O-035
Instant noodles: The impact of processing variables on the quality attributes
C. A. Widjaya (2), L. CATO (1), D. M. Small (2)
(1) Department of Agriculture W. A. (DAFWA), Perth, WA 6151, Australia; (2) RMIT University, Melbourne, Victoria, Australia

Instant noodles are the fastest growing sector in the noodle industry and have gained popularity amongst western countries due to the convenience of fast preparation, desired flavour and texture. The aim of this study has been to evaluate the quality of instant noodles processed using varying conditions including mixing time (1–5 min), resting time (0–30 min) and the steaming time (2–4 min) as well as the number of folding steps used during the sheeting process (0–4 times). Resting times were investigated at two stages of the process, after the first sheeting through the largest roll gap of the noodle maker and after the final sheeting of the dough sheet. Instant noodle quality attributes assessed include noodle colour measured using the Minolta Chromameter (CR-100) and noodle texture assessed by texture analyser (TAXT2). The experimental design and statistical evaluation involved response surface methodology (RSM) following second order central composite face centered design (Design Expert version 7.1). It was found that mixing and resting times did not impact noodle colour significantly, however noodle texture (hardness) was significantly and negatively correlated with mixing time. Brightness (Minolta L* values) of instant noodles was significantly affected by steaming time and the number of folds during the processing. Increasing both steaming time and number of folds resulted in enhanced brightness of the final product. While hardness was not significantly influenced by varying the steaming time or the number of folding steps, steaming time was significantly and positively correlated with the yellowness (Minolta b* values) of the noodles.

O-067
Is the wheat flour supplemented with malted barley flour or fungal alpha-amylase affecting the Asian noodle quality?
G. HOU (1), B. Lee (1), D. Shelton (1)
(1) Wheat Marketing Center, Inc., Portland, OR, USA

Asian noodles have become a popular product in the U.S., but specially marketed noodle flours have limited availability. Most of noodle manufacturers in the U.S. use bread flour for producing Asian noodles. Bread flour is commonly supplemented with malted barley flour or fungal alphaamylaseto improve baking performance. However, there are some concerns to the noodle manufacturers whether these added malt or fungal alpha-amylase have a negative impact on noodle color and texture because amylases may breakdown the starch and soften the boiled noodle texture, and possibly make noodle color less stable. In this study, four commercial classes of U.S. wheat -soft white, hard red spring, hard red winter, and hard white wheat, were milled using a Miag pilot mill to produce straight-grade flours (~70% extraction) and60% patent flours. Malted barley flour was added into each flour to achieve~250 s falling number and fungal alpha-amylase was added to each flour according to the manufacturer recommended dosage based on each flour’s initial falling number. These flours were made into Chinese fresh white salted noodles on a pilot scale noodle line, and the noodle color and boiled noodle texture were measured. Preliminary results indicated that both the malted barley flour and fungal alpha-amylase did not significantly affect the cooked noodle texture measured with a TA.XTplus Texture Analyzer, but the fungal alpha-amylase significantly reduced the fresh noodle color stability (lightness L* and yellowness b* values) from 0 to 48 hr. As the amount of malted barley flour in the wheat flour was increased to achieve the falling number of 180-200 s, the noodle lightness L* reduced significantly, but the cooked noodle texture was little changed. These results suggest that the supplementary malted barley flour has little influence on the fresh white salted noodle quality. Wheat flour supplemented with malted barley flour can be used forsaking fresh noodle products; nevertheless, flour supplemented with fungal alpha-amylase is not desirable for producing fresh noodles because it makes noodle color duller and yellower.

O-106
Effect of dough rheology on gas cell stability and baked product microstructure
M. PICKETT (1), H. Dogan (1)
(1) Kansas State University, Department of Grain Science, Shellenberger Hall, Manhattan, KS, USA

The quality and functionality of baked foods rely on their cellular foam structure. Dough exhibits extremely complex rheological properties which affects the number of bubbles and their size distributions. The ability of the gas cells to resist failure and remain stable throughout the proofing and baking process is critical to final bread texture and volume. In this study we developed an experimental protocol which allows us to capture micro structural properties of dough systems made from three different wheat flours. Doughs were prepared according to AACC Method 10-10B optimized straight-dough bread-making method. Sections from unproofed (0 min), underproofed (19 min) and optimally proofed (38 min) doughs were carefully cut and frozen at –80°C. Several small specimens of frozen dough were cut from each loaf prior to micro structural analysis. Dough samples were scanned using a high resolution desktop X-ray micro-CT system, Skyscan1072(Skyscan, Belgium) consists of an X-ray tube operating at a voltage of 75 kVand current of 98 µA, an X-ray detector and a CCD-camera. X-ray images were obtained from 100 rotation views through 180° of rotation. The scanning process was controlled by a software package, which also allows micro tomographical reconstruction using a filtered back-projection algorithm. Angular projections were used to generate 2-D cross-sectional images. 3-Dobjects were then reconstructed from multiple 2-D images and virtually sliced for quantitative analysis. Hundreds of reconstructed cross sectional images were analyzed using CTAn (v.1.7) processing, and analysis software. The gas bubbles were clearly visible within the dough matrix by their low grey value(low absorption coefficient). 3-D analysis of the bubbles indicated that the dough void fractions changes dramatically during proof time. Gas cell size distributions ranged from 0.29 and 0.43 mm for the under proofed and optimally proofed doughs, respectively. A corresponding increase was observed from 61.1% to 73.7% in void volume fraction. Average cell wall thickness decreased from 0.10 mm to 0.09 mm during proofing. Fully proofed doughs were baked and gas cell structure in the final baked product was characterized using C-Cell imaging system. The biaxial extensional rheological properties of dough measured using Stable Micro Systems Ltd.D/R Dough Inflation System were correlated with microstructure of both proofed dough and final baked product.

P-035
Effects of addition of mushroom fiber on the baking qualities and on the total dietary fiber content of baked products
W. CHEUNG (2), P. Cheung (2), P. Ng (1)
(1) Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, USA; (2) Food and Nutritional Sciences, The
Chinese University of Hong Kong, Shatin, Hong Kong

Sclerotia of Pleurotus tube-regium contains over 80% total dietary fiber(TDF). It has a high degree of whiteness which makes it a possible source of dietary fiber for addition to food. Due to its low moisture, plain taste, and higher fiber content, the sclerotia of the mushroom can be ground to a fine powder and added to food products without further treatment. Effects of addition of the mushroom powder (MP) on bakery product qualities as well as the effect of baking processes on TDF content of the MP added to the baked products were studied. Three bakery products (bread, cookies and crackers)were used in the experiment. 0%, 5%, 7.5% or 10% (w/w) MP was added to each of the bakery formulations. It was found that the volume of bread significantly decreased and the hardness of bread significantly increased when7.5% or higher of MP was added. Diameter of cookies and the hardness of cookies significantly decreased when 7.5% or higher of MP was added. For crackers, length, width, thickness and hardness decreased with increasing percentage of MP added. A decrease in moisture was observed for crackers with addition of the MP. Among the products containing 7.5% MP, TDF content of crackers increased after baking, while TDF contents of both bread and cookies decreased after baking. No significant changes in size and texture were found for any of the three studied bakery products with incorporation of5% (w/w) mushroom powder. Thus, sclerotia of Pleurotus tube-regium could be a possible source of fiber for enrichment of bakery products.

P-044
Resistant starch content of re-made maize tortillas, and their physicochemical and textural properties
G. ARAMBULA-VILLA (1), S. Galvan-Alvarez (2), E. Gutierrez-Arias (1), I.Resendiz-Lopez (2), A. L. Arambula-Peña (1)
(1) CINVESTAV-Qro., Queretaro, Qro., Mexico; (2) Universidad Autonoma de Queretaro, Facultad de Ciencias Quimicas, Queretaro, Qro., Mexico

The maize tortilla is a basic food in the daily diet of the population of Mexico and Central America. Due to its high contained of starch (72%), in Mexico, a high percentage of the population presents problems of health as diabetes and obesity. To diminish the caloric content of this type of food, it is possible to process them and the native starch transforms in resistant starch. In this work, different forms were evaluated to increase the contents of resistant starch in the maize tortillas. The variables and levels tested, were: type of maize, white and yellow; type of process, addition of pericarp and re-processing of tortilla; and temperature of dehydration, 30 and 60°C. The tortillas were produced, characterized, dehydrated and re-processed several times. For all treatments, the content of resistant starch (RS), retrograded resistant starch (RRS),physicochemical and texture properties were determined. The RS and RRS increased from 3.41 to 5.90% and from 1.13 to 2.69% respectively, respect to the re-process number. In some treatments, the water absorption capacity(WAC), moisture content, maximum (MV) and retrogradation viscosity (RV)of the flours, and the tensile and cutting force of tortillas were negatively affected. Tortillas elaborated with white maize presented higher content of RS (5.90%), and RRS (2.36%), than those of yellow maize, and their characteristics were similar to that tortillas prepared by the traditional method. Two types of maize produced tortillas of good quality during the first making process, although the MV and RV were different, showing the biggest values those tortillas prepared with yellow maize. The flours of both types of maize presented similar WAC (1.84 mL/g), in the first, the second and the third re-process times. The same flours, after transforming them into tortillas, presented the best characteristics. The RS and RRS contents were similar in tortillas from two types of maize. Although all the variables evaluated, affected the RS and RRS contents, the biggest increases were appeared when changed the type of process and the dehydration temperatures, mainly. The re-processes, which involve cooking of mass and dehydration of tortillas, were who provoked the biggest increases of RS and RRS, and the tortillas were obtained with acceptable characteristics for the consumer.

P-046
Physical and molecular properties of total and resistant starches from corn with different doses of mutant amylose-extender and floury-1 alleles for use in Hispanic food products
N. YAO (1), A. V. Paez (2), L. M. Pollak (1), P. J. White (1)
(1) Iowa State University; (2) GEI, Johnston, IA

Corn types with different numbers of mutant amylose-extender (ae) andfloury-1 (fl1) alleles: #1, aeaeae; #2, fl1fl1fl1; #3 aeaefl1; and #4 fl1fl1aewere developed for use in making Hispanic food products with high resistant starch content. Starches from these corn types were evaluated for pasting properties with a Rapid Visco Analyser (RVA) and for thermal properties with a Differential Scanning Calorimeter. #1 had a low peak viscosity (PV) caused by incomplete gelatinization, whereas #3 had the greatest PV and breakdown. Starches #2, #3 and #4 had pasting temperatures of 78–81°C. #2 had the lowest onset temperature and greatest enthalpy. #3 and #1 had similar onset and peak temperatures, both higher than those of #2 and #4. The gel strength of the starch cooked by RVA then stored at 4°C for 10 days (retrograded) was evaluated by using a Texture Analyzer. The #1 gel appeared watery and had the lowest strength of 30 g. The #3 gel, although exhibiting syneresis, had greater gel strength (286–305 g) than #2 and #4 (194–209 g). Resistant starches (RS) in the original starches were: #1, 54.6%; #2, 1.1%; #3, 5.1%; #4,1.9%. The structures of the original starches, of the RS in the original starch(RS-O) and of the retrograded starch (RS-R), were evaluated by using size exclusion chromatography. The chain-length distribution of amylopectin was analyzed by fluorophore-assisted carbohydrate electrophoresis. Starch #1 had greater % amylose than the other starches. RS-O of all starches had a lower % amylopectin and a higher % low-molecular weight (MW) amylose than in their original starches. The RS-R from all starches had no amylopectin or high-MW amylose; however, the low-MW amylose (fractions 34-47) of RS-R from #2, #3, and #4 had strong blue values, with a different maximum absorbance wavelength than that of #1. The bigger chain lengths (DP 35-60)were greater in #1 and #3 than in #2 and #4, and the smaller chain lengths (DP10-20) were greater in #2 and #4 than in #1 and #3. In general, #3 starch inherited some pasting, thermal and structural characteristics from both #1 and#2, but was distinctly different from #4. The appropriate dosage of ae with fl1will be further pursued to optimize structure-function relationships in food applications.

P-055
The incorporation of Teff (Eragrostis teff) in bread-making technology
E. Ben-Fayed (1), P. Ainsworth (1), V. STOJCESKA (1)
(1) The Manchester Metropolitan University

Teff is a little-known cereal grain. It is indigenous cereal in Africa and is currently grown in some areas of the Netherlands, the United States and Canada. It has a very high fibre and iron content and an excellent source of essential amino acids, especially lysine, the amino acid that is most often deficient in grain foods. Teff has a high calcium content, and contains high levels of phosphorous, copper, aluminum, barium, and thiamine. The objective of this work was to incorporate Teff in breads and to study its effect on the textural properties of baked bread. Teff flour at levels of 10, 20 and30% was added to the dough mix and a standard wheat loaf was used as a reference. A number of analyses were conducted using a Farinograph to determine water absorption ability, the rapeseed displacement method to determine loaf volume, a texture analyzer to study texture and shelf life over a period of 6 days and a Hunter Lab Colorimeter to record colours of breads. The results showed that addition of Teff increased the level of water absorption and decreased the loaf volume, increased stability and decreased dough development time at samples containing above 20% Teff flour and increased the degree of softening at 30% Teff. Lightness was negatively affected by the higher level of Teff, while crumb redness and yellowness were positively affected. The textural characteristics revealed increasing of crumb firmness at 20 and 30% Teff addition. Further increase in crumb firmness at20 and 30% Teff addition was recorded during the each day of storage.

P-058
Evaluation of the effects of Jatropha curcas L. flours on the quality of cookies
L. López (2), J. Herrera (1), S. Simental (2), E. Soto (2), J. Chavez (2), A.Fuentes (2), N. VERA (2)
(1) Centro de Productos Bioticos del Instituto Politecnico Nacional; (2) Instituto de Ciencias Agropecuarias de la Universidad Autonoma del Estado de Hidalgo

The Jatropha curcas L. flour has an important value nutritional for the bread products. The aim of the present work was to characterize the dough texture, adhesiveness and extensibility of cookies fortified with Jatropha curcas L.flour. A proximal analysis was developed. After that dough was prepared with Wheat Flour (WF) fortified with various levels of Jatropha curcas L. flour(2.5, 5, 7.5,10 and 12.5%). Later the rheological analyses (TPA, adhesiveness and extensibility) were performed by using a TA.XT2i texture analyzer(Stable Micro Ssystems Ltd, Surrey, UK) in a compression mode. The chemical composition of the flour was 6.5% protein for WF and 25% protein for J.curcas flour. The cookie fortified with 10% of had 24.6% protein content as compared to 6.4% in the regular product, which agreed with other results reported in the literature. The addition of 10 and 12.5% protein content produced a decrease in the firmness and consistency, and an increase in the cohesiveness of the dough. Generally speaking, higher amounts of precipitate(30%) did not significantly affect the firmness, consistency or cohesiveness of the dough. The adhesiveness increased particularly in samples prepared with 10 and 12.5% of J. curcas flour. The presence of Jatropha curcas L.flour produced an excellent firmness and consistency of the cookies and an increase in its cohesiveness, which favours the production of a high-quality product. Using flour J. curcas fortified cookies to give a protein intake and nutrition.

P-059
Jatropha curcas L. flour addition to wheat flour tortillas and their effects textural properties
I. Villafuerte (2), J. Herrera (1), J. Chavez (2), M. Santamaria (2), A. Fuentes (2), N. VERA (2)
(1) Centro de Desarrollo de Productos Bioticos del IPN; (2) Centro de Investigaciones en Ciencias y Tecnologia de los Alimentos del ICAP-UAEH

Texture is a property of major importance in the evaluation of baked products. The objective of this investigation was to study the effects of added Jatrophacurcas L. flour into wheat flour tortillas on protein content and tortilla rheology. Total protein content according AOAC (1995); tortilla extensibility and texture profile analysis test were conducted using a texture analyzer (TAHDi).Wheat-J. curcas mixture dough making were prepared with wheat flours (WF) fortifying with various levels (Jc: 5.0, 10.0, 15.0 and 20.0%) were evaluated. The tortillas made with the hot-press method. The extensibility of wheat flour tortillas showed that, increasing the J. curcas flour percentage from 0% to 20%, the dough were less extensible, the best mixture was 10% J.curcas wheat flour tortillas. Stretchability measurements were repeatable and are an important textural property of wheat flour tortillas J. curcas flour. This indicates that the tortillas of the blends are still strong and elastic. However, when the amount of Jatropha flour was increased up to 20%, the tortillas flour became very strong. The hardness increased particularly in samples prepared with 20% of Jatropha flour. The presence proteins produced a increased in the firmness and consistency of the dough and an decreased its cohesiveness, which favours the production of a high-quality product. The content of protein was 24.5% and 11% of fat in wheat flour tortillas with 10% of J. curcas flour.

P-074  (likely)
Spectral evaluation of anti-staling enzymes
M. NIELSEN (1), J. Jensen (2), S. Engelsen (2)
(1) Novozymes A/S, DK-2880 Bagsvaerd, Denmark; (2) University of Copenhagen, DK-1958 Frederiksberg C, Denmark

Staling of bread is a collective name for all the deteriorating changes occurring in bread during storage. The most important changes examined in this study were the increase in firmness of the bread crumb due to retrogradation of starch, changes in the gluten phase and loss of water. Staling of bread has been studied by a number of experimental methods including differential scanning calorimetry (DSC), Ultrasound measurements (US), Xray diffraction (X-RAY) and nuclear magnetic resonance (NMR) and the textural changes has been measured by Texture Analyzer. In this study the aim was at finding a sensitive spectroscopic method capable of measuring the textural changes (staling) happening during storage of bread for up to 21 days by the use of spectroscopy. The application of Fourier transform-infrared spectroscopy (FT-IR) and Near Infrared spectroscopy (NIR) in combination with chemo metrics were investigated on whole wheat bread with or without added anti-staling enzymes (Novamyl® or BAN®). For this purpose 180 bread samples, with or without added enzymes, were measured (TA, NIR and FTIR)with decreasing intensity up to 23 days after baking. The results showed that FT-IR spectroscopy combined with chemometrics was a suitable method to predict the degree of staling, whereas NIR spectroscopy was able to differentiate between the enzyme treatments and to predict the degree of staling. The results are interpreted in great detail and while the FT-IR results could be directly related to starch retrogradation the NIR results were of more holistic nature.

P-088
Dried flour-oil composites for lipid delivery in low-fat cake mixes
M. SINGH (1)
(1) USDA-ARS-NCAUR

The aim of this study was to prepare and evaluate flour-oil composites for lipid delivery as a dry ingredient in cake mixes at different levels of fat. Four excess steam jet-cooked composites containing wheat flour and varied amounts of canola oil (30 to 55%) were drum dried and used as a replacement for fat and part of the flour in low-fat cake mix formulations. Cakes were baked using the mixes and compared to those prepared with same amount of canola oil added as a source of fat. Specific gravity and viscosity of cake batters were measured. The cakes were analyzed for crumb grain using digital scans of the cake crumb; color by Labscan Xe Hunter colorimeter; texture using the TA Texture analyzer with ½ inch acrylic probe (TA 10); and water activity using Aqua Lab water activity meter, model series 3. The effects of storage were determined by evaluating cakes stored at 0, 1, 4, and 7 days. Cakes made with the composites were softer as they required significantly less force than those made with equivalent canola oil and had more spring as measured by the texture analyzer. Similar differences in texture were observed with cakes stored for a week. With storage the cake lost their softness and spring. The cakes made with composites retained their softness and moisture better than control cakes made with equivalent flour and oil. The crumb grain and color were not significantly affected by the use of composites as source of fat in the cakes. The composites have great potential for use as an ingredient in baking industry for delivery of lipids for bake mixes.

P-090
Rice-shaped extruded kernels: Grains for Hope
J. YOO (1), S. Alavi (1), K. Adhikari (1), M. D. Haub (1), R. A. Aberle (2), G. R. Huber (2)
(1) Kansas State University, Manhattan, KS, USA; (2) XIM Group, Sabetha, KS, USA

Rice-shaped extruded kernels were developed to address nutritional deficiencies in developing countries and utilize sorghum which is a dominant crop in Africa but has been limited in food applications due to its poor digestibility and protein functionality. Also, as these extruded kernels were pre-cooked, it was expected to shorten the cooking time. Grains for Hope “rice” kernels were made with blends of corn and wheat flour, sorghum and wheat flour, or rice flour alone using a pilot-scale twin screw extruder. Each blend was fortified with an enrichment blend including vitamin A and C, folic acid, and iron. Extrusion conditions were controlled to obtain optimized product quality depending on the properties of these blends. Cooking quality test was conducted to determine cooking loss and water absorption. Texture profile analysis (TPA) and color measurements were conducted using TAXT2 and Minolta colorimeter, respectively, and the results were correlated with descriptive analysis (DA) data. Retention of vitamins after processing was also evaluated. Extruded kernels with corn and wheat flour were high in yellowness and greenness. Kernels with sorghum and wheat flour showed highest cooking loss (13.4%) and water absorption (124.4%). Mean separation by least significant difference (Fisher) indicated that extruded kernels with sorghum and wheat flour were significantly different (P < 0.05) from the other samples for both TPA and DA results. Instrumentally measured adhesiveness with TA-XT2 was highly correlated to 6 of the 8 texture sensory attributes. One serving size of final product (150 g) provided up to 69.8%, 24.4%,84.4%, and 96.9% of RDI of vitamin A, vitamin C, folic acid, and iron, respectively. After extrusion processing, the retention % of vitamin A was about 44% or less, however retention % of vitamin C was lower at 42% or less.

P-100
The influence of adding chia flour and vita-gluten on the technological quality and shelf life of bread loaves
P. Luna Pizarro (2), A. Silva Coelho (1), N. Sammán (2), M. Dupas Hubinger (3), Y. CHANG (1)
(1) Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Brazil; (2) Faculty of Engineering, National University of Jujuy, Argentine; (3) Food Engineering Department, Faculty of Food Engineering, State University of Campinas, Brazil

The current trend in nutrition indicates the importance of incorporating in to the diet essential fatty acids and dietary fiber; the seed of chia fulfills these conditions. Chia (Salvia hispanica L.) is a seed native to middle America characterized by a high alpha linolenic acid content (w3 = 61 g/100 g lipids)and high protein content (21.6 g/100 g chia, d.w.b.), and thus its addition to bread is currently being studied. The objective of the present work was to study the addition of chia flour in combination with vita-gluten (3-0.6, 17-0.6,3-3.4, 17-3.4, 0-2, 20-2, 10-0, 10-4, 10-2%), to wheat flour and determine the influence on the technological quality and shelf life of bread loaves. The loaves were produced by the direct dough method, using a 22 complete factorial design, and the respective mathematical models were obtained and the response surfaces for each variable evaluated. Volume, moisture content, compression force and color were studied during the shelf life of 1, 4 and 7days of storage. The response surfaces showed that the specific volume did not present significant variation up to 10% of chia flour content. With respect to moisture content, the values remained practically constant during storage, increasing with increasing concentration of chia flour, from 17 to 20%. High levels of chia flour decreased the hue angle values (H*), and the values for L*showed the same tendency. Nevertheless the color of the loaves did not change during storage. The compression force was affected by the addition of chia flour and vita-gluten, the best responses and crumb texture quality of the loaves being obtained with lower chia flour and vita-gluten contents. The results showed that the substitution of up to 10% of the wheat flour with chia flour presented acceptable technological characteristics in the elaboration of bread loaves.

P-113
Effects of pearling level on physical, compositional, and cooking properties of selected Western Canadian barley varieties
L. M. HUMISKI (3), M. Izydorczyk (1), L. Malcolmson (2)
(1) Canadian Grain Commission, Winnipeg, MB, Canada; (2) Canadian International Grains Institute, Winnipeg, MB, Canada; (3) University of Manitoba, Winnipeg, MB, Canada

Interest in incorporating barley into the diet of North American consumers isincreasing considerably due to the reported health benefits associated with barley. The most common method for processing barley for food use is pearling which involves the gradual removal of the outer layers of the kernel including the hull by abrasive action. Limited information exists about the effect of pearling level on the physical, compositional, and cooking properties of barley, especially hulless barley varieties. In this study, ten genotypes of Western Canadian barley differing in hull and starch characteristics were pearled to three differing levels (5%, 10% and 25%) with a Satake grain testing mill. Multivariate analysis was performed to determine differences among genotypes and among different pearling levels. Genotypes with high amylose or low amylose (waxy) starch were found to be higher in protein and beta-glucan contents than genotypes with normal starch. In addition, high amylose genotypes were harder as determined by the single kernel characterization system (SKCS) and had firmer instrumental cooked texture as determined by the texture analyzer (TA-XT2 Plus). As pearling level increased, both starch content and lightness (L*) increased. In contrast, a decrease in protein, arabinoxylans, and free phenolic acids was observed with increasing pearling levels. Small differences in beta-glucan were observed as the degree of pearling increased Differences in the sensory characteristics ofthe cooked pearled barley were also observed by a trained sensory panel.

P-114
Influence of pinto bean (Phaseolus vulgaris L.) flour and modified food starch on some physical properties of sugar-snap cookies
A. D. TANOJO (1), R. Ramasamy (1), K. D. Dolan (1)
(1) Michigan State University, East Lansing, MI, USA

Common beans (Phaseolus vulgaris L.) are a traditional food in the human diet and are rich in dietary fiber, protein, vitamins, and essential minerals such as iron, zinc, and calcium. Pinto bean flour addition to the sugar-snap cookie was chosen due to its familiar use in many food products: refried beans, soups, salads, and chilies, and are globally well known. In addition, functional food and nutraceutical industries are increasingly promoting the value-added products with better nutrition profiles and health-promoting properties. The objective of this experiment was to study the effects of pinto bean flour and modified food starch on some physical characteristics of sugar-snap cookies. Two separate experimental sets were conducted: 1) different levels of pinto bean flour (control, 10%, 20%, and 30% flour basis) were added into the sugar snap cookies formulation, 2) one percent (flour basis) of Baka-Snak® food starch-modified from National Starch was incorporated into experimental set1. Initially, the dough characteristics were observed. The higher the pinto bean flour content, the tougher the dough was. Modified starch addition made the dough fluffier, softer, and smoother, as to compare to the ones without modified starch counterparts. The dough compressibility values were slightly increased with increasing levels of pinto bean flour for both with and without the addition of modified starch. Cookies’ physical characteristics on color, texture, height, and spreadability (diameter) were further examined. The color L-values (lightness) were increased with increasing level of pinto bean flour in the formulation. The addition of modified starch also increased the L-values in all levels (P < 0.05). The cookie’s breaking strength was also increased in the higher level of added pinto bean flour cookies. In the absence of modified starch, the average height of six cookies was found to be 5.57, 5.76, 6.64, and6.65 cm for control, 10%, 20% and 30%, respectively. The same trend happened to the height of six cookies with added modified starch: 5.62, 5.82,6.68, and 6.71 cm. However, the average values of six cookies diameter were generally decreased with pinto bean flour addition, and increased with modified starch addition. In conclusion, Baka-Snak® modified food starch improves the quality of sugar-snap cookies with partially added pinto bean flour in terms of more lightness, less breakage, and increasing height and spreadability, which are desirable characteristics in cookies.

P-127
Ecological alternative heat sources to cook maize tortilla
G. ARAMBULA-VILLA (1), E. Gutierrez-Arias (1), I. Guzman-Acosta (2)
(1) CINVESTAV-Qro., Queretaro, Qro. Mexico; (2) Universidad Tecnologica de San Juan del Rio, Queretaro

Maize tortilla is the basic food of daily consumption in Mexico. A main step in the elaboration of maize tortilla is the baking. Tortillas are baked in a continuous oven on a metallic gas. Today, tortillas machines, which consume gas L.P. are used. The fire produces some pollution gases, poor thermal energy transfer between the hot plate of the conveyor and the product, the process is slow and inefficient. The baking stage of tortillas elaboration process has not had important changes. In this work, tortillas elaborated by the traditional method and cooked in an infrared oven (IR) with different times and cooking temperatures, and in a microwaves (MW) stove with times of0.0, 1.0 and 24.0 hrs, were tested and compared with cooked tortillas on coal heated with L.P. gas. Quality parameters were determined. Tortillas elaborated with traditional and lR methods were similar and their quality characteristics (color, texture and puffing degree) were very good. Advantages of IR ovens are: capability of penetration and uniform heating, direct energy transfer with high efficiency, clean process without pollution and safety to humans and food products. Base on results we concluded that the IR method is one of the best alternatives for the maize tortilla elaboration.

P-138
Effect of nitrogen fertilization on physical dough properties and baking quality of three experimental lines of wheat (Triticum aestivum L.) of the northwestern of Mexico
F. Vásquez-Lara (2), J. Mercado-Ruiz (2), M. Granados-Nevárez (2), M. A. Camacho-Casas (1), A. R. ISLAS-RUBIO (2)
(1) Campo Experimental Valle del Yaqui-CIRNO-INIFAP; (2) Centro de Investigación en Alimentación y Desarrollo, A.C.

Four schemes of nitrogen fertilization (Nd) were applied to three experimental lines of wheat (EL), evaluating their effect on protein content, some physical properties of the dough and baking performance. Nitrogen fertilization treatments were Nd1 (0-0-0), Nd2 (50-50-50), Nd3 (150-0-0) and Nd4 (100-100-100); the numbers in parenthesis indicates kg of urea/ha applied at replanting, first and second auxiliary irrigation, respectively. The amount of total protein was higher in the EL-3 (13.22%), whereas EL-1 showed the smaller amount (11.01%). Physical dough tests were carried out with the texture analyzer TA-XT2. The extensibility (Ext) of dough with Nd3 was similar to the control (Nd1), independently of the EL, however, the maximum resistance (R max) was observed when this Nd was applied to LE1 and 3. On the other hand, between the split application of urea to all EL, Nd2 resulted in dough with the highest R max. The split urea application also favored the baking quality of the EL tested. It appears that dough with a well balanced gluten determined the baking quality of the EL

P-139
Effect of processing conditions on tofu characteristics
N. WANG (1), L. Maximiuk (1), R. Toews (1)
(1) Canadian Grain Commission, Grain Research Laboratory, Winnipeg, Canada

Tofu is a soybean (Glycine max) protein gel-like product and its physical properties such as yield, texture and color determine the quality of tofu. Factors including solids in soymilk, concentration of coagulant, stirring speed and time, and temperature of coagulation influence tofu quality. The effect of these factors on tofu characteristics was investigated using response surface methodology(RSM). It was found that concentration of coagulant and the ratio of bean to water were the most significant factors affecting tofu yield, textural properties (hardness, fracturability, adhesiveness, gumminess, springiness and chewiness) and color (L*, a* and b* value), followed by stirring time, temperature of coagulation and stirring speed. Models for predicting tofu characteristics were developed as functions of processing factors (solids in soymilk, concentration of coagulant, stirring speed and time, and temperature of coagulation).

P-140
On the storage period of stone-milled buckwheat flour: Changes in flavor, scent and texture
I. HAYASHI (1), S. Kawasaki (2), T. Igasaki (1), Y. Hayashida (1), N. Murayama (1)
(1) Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan; (2) Kumamoto Flour Milling Co. Ltd., Kumamoto, Japan

The noodle made of buckwheat flour is one of the Japanese traditional foods, and is preferred to be fresh in its flavor, scent and texture. The objective of this study was to test how the storage period of stone-milled buckwheat flour affects the flavor and texture. The sensory evaluation and instrumental analyses were made in a set of stone-milled buckwheat flour stored for 0, 7,and 14 days at 25° in craft-bags. The moisture content decreased with the longer stored periods. In the sensory evaluation of flavor, the stored samples showed high scores in the bitterness and the astringency when compared with the non-stored sample (n = 6, P < 0.05, Students’ t-test). In the instrumental analyses using the taste sensors, some of the sensor outputs were significantly different with different storage periods (n = 6, P < 0.05, Students’ t-test),being consistent with the result of the sensory evaluation. In the sensory evaluation of scent, the score decreased with the longer stored periods. In the sensory evaluation of texture, the score of the hardness and the smoothness changed with the storage. In the instrumental analyses using the texture analyzer, the stretch decreased with the longer stored periods. Since the RapidVisco analysis showed an increase of the max viscosity with the longer stored periods, it was suggested that degradation of the starch during the storage cause the texture change. The present study showed that a long period of the storage can change the flavor, scent, and texture of stone-milled buckwheat flour, and that the instrumental analyses we utilized can be valid for the quantitative evaluations of such changes.

P-146
Effect of ozonated flour on bread quality
H. SANDHU (2), Y. Liu (1), S. Simsek (2), G. Hareland (3), F. Manthey (2)
(1) North Dakota State University, Department of Cereal and Food Sciences, Fargo, ND; (2) North Dakota State University, Department of Plant Sciences, Fargo, ND; (3) USDA/ARS Wheat Quality Laboratory, North Dakota State University, Fargo, ND

Ozone is a tri-atomic molecule (O3), and is a powerful oxidant with anoxidation reduction potential of 2.07 V. The use of ozone in the food industry has been limited mainly to shelf life extension of commodities. Recently, there has been renewed interest in ozone and its application in food processing. This project was aimed at studying the effect of ozonated flour on bread quality. Ozone generator model number CDO-8000 was used to ozonate commercial flour, at 1500 ppm for 40 minutes. The ozonated flour was added to commercial flour at 10%, 20%, and 30% (w/w) levels, which were compared with the control flour that was not ozonated. Moisture content, Farinograph, and Rapid viscoanalyzer (RVA) measurements were made according to AACC Methods 44-15-A, 54-21, and 76-21, respectively. Texture analysis and modified extensigraph measurements were made using the Texture analyzer (TA-XT2 texture analyzer). The C-cell-digital imaging instrument was used to compare bread structure and quality. Results showed that ozonated flour added at the 10% level produced bread with the highest specific loaf volume and increased bread firmness. RVA results showed that peak value, breakdown value, final viscosity, and setback values increased with increasing amounts of ozonated flour added to the commercial flour. CCell data showed that the 10% ozonated flour produced bread with the least number of holes and the finest cell structure than the bread produced with higher levels of ozonated flour.

P-147
Effect of defatted maize germ flour addition on the quality attributes of wheat bread
M. SIDDIQ (1), M. Nasir (2), M. S. Butt (2), R. Ravi (1), K. D. Dolan (1), J. B. Harte (1)
(1) Michigan State University; (2) NIFST, Univ. of Agri., Faisalabad, Pakistan

Defatted maize (Zea mays L.) germ cake, a by-product of the corn oil industry, is rich in protein content, dietary fiber and minerals. Presently, the defatted maize germ (DMG) is mainly used for animal feed. The objective of this study was to assess the feasibility of using this nutrient-rich food ingredient in bread by substituting wheat flour with 5–20% DMG flour. Breads prepared with wheat-DMG flour blends were analyzed for loaf volume, density, Hunter color values, instrumental texture, and selected sensory attributes. Our results showed that loaf volumes decreased significantly, from 318.8 mL to 216.3 mL, as the DMG flour level was increased from 0 to 20%; whereas, bread density increased significantly at all four DMG flour levels. The bread made with 100% wheat flour (control) was lighter in color, as shown by higher Hunter “L” values than those made with added DMG flour. A similar trend was observed for chroma and hue angle values, which were significantly higher in treatment breads. The bread slice firmness, measured by SMS Texture Analyzer (TA-XT 2i), was significantly higher for breads containing DMG flours, 61.58 N in 20% DMG bread as compared to 32.84 N for the control bread. In general, minimal or no differences were observed for the sensory attributes of crumb color, cells uniformity, aroma, firmness, mouthfeel, and off flavor in breads with up to15% DMG flour. However, most of the sensory attributes were impacted negatively with 20% DMG flour addition. Based on the findings of this study, it is concluded that bread with acceptable quality attributes could be made with up to 15% DMG flour.

P-149 (likely)
Contribution of lipids to flour and dough properties and Mantou-making quality of wheat flour
S. YAN (2), H. Sun (1), W. Jiang (1), F. MacRitchie (2)
(1) Academy of State Administration of Grain, Beijing, 100037, PRC; (2) Kansas State University, Manhattan, KS, USA

Wheat flours from three wheat varieties, Karl (American Hard Wheat with strong gluten), Jagger (American Hard Wheat with weak gluten) and Zimai 12(Chinese Soft Wheat with weak gluten), and their defatted counterparts, obtained after lipids were extracted by chloroform, were used to investigate the effect of lipids on physicochemical properties and Mantou-making quality of wheat flour. Mantou is steamed bread. Microstructure and thermal properties of these samples were measured by scanning electron microscopy(SEM) and differential scanning calorimeter (DSC) respectively. The defatted flours had more single starch granules and higher gelatinization enthalpies than the normal flour samples. Rheological properties were determined by Farinograph, Rapid Visco Analyzer and Mixolab. In contrast to the normal wheat flour, defatted flour had a higher water absorption, longer pasting peak time, higher peak and hold viscosities, but lower setback and breakdown. Characteristics of the first two stages of Mixolab, dough development and protein reduction, did not show differences except for water absorption. A distinct variation during the other three stages, starch gelatinization, amylasic activity and starch gelling were observed. It showed that defatted flour had a higher maximum consistency during starch gelatinization, a lower amylasic activity and a higher consistency value as dough temperature was lowered. CCELL technology and Texture Analyzer were used to test internal grain and texture of Mantou. It showed that the volume of Mantou made from defatted flour did not change, but the crumb grain was poorer, showing bigger cell diameter, less cell number and thicker cell wall compared to those made from non-defatted samples. Results of Texture Analyzer tests showed that Mantou made from defatted flours of two weak gluten wheat had higher hardness and resilience than that made from non-defatted samples but this was not found for the strong gluten wheat. Keywords: lipids, defatted flour, physicochemical properties, Mantou making quality, wheat.

P-170
Modification of extensigraph dough preparation method developed for wheat breeding lines and commercial wheat
R. Y. CHEN (2), B. W. Seabourn (2), F. Xie (1)
(1) Department of Grain Science, Kansas State University; (2) USDA, ARS, GMPRC

Dough rheological characteristics – resistance to extension and extensibility, are very important wheat flour quality traits for the milling and baking industries, and for new wheat varietal selection in wheat breeding programs. Current available techniques or test methods, such as the AACCI extensigraph standard method or the small-scale TA-XT2 Kieffer method, have some limitations with respect to flour sample size, testing time, water absorption, sample throughput, data interpretation, and results. A modified extensigraph test method utilizing 100 g flour and 2 g salt and adapting 50-g Farinograph optimum water absorption for dough prepared in a 100-g mixer with an orbital speed of 86 rpm was developed to measure dough rheological characteristics. The dough is mixed until it is fully developed. Mix time was much shorter and dough preparation was much easier in the 100-g mixer than that in the 300-gFarinograph. Data generated by the modified method is highly correlated with data obtained by the standard extensigraph method (AACC method 54-10).The correlation coefficients (r) for 93 pairs of each of six extensigraph dough characteristics of 31 different tested wheat samples, grown in Texas, Oklahoma, Kansas, Colorado, Nebraska, South Dakota, and Montana were0.95 for resistance to extension, 0.93 for maximum resistance to extension,0.80 for extensibility, 0.93 for ratio of resistance to extension to extensibility,0.92 for ratio of maximum resistance to extension to extensibility, and 0.81for the area under the curve. There were also significant correlation coefficients for the data of extensigraph dough characteristics evaluated at each of three tests (30, 60, and 90 min.) between the modified and standard methods. Therefore, the modified extensigraph test method is a useful and valuable alternative for wheat breeding programs, milling and baking industries, crop quality surveys, and wheat quality research due to its smaller flour sample requirement and the reduced time required for dough preparation.

P-172
Dough strength: A measurement of quality in wheat flours
F. Vásquez-Lara (2), M. Granados-Nevárez (2), B. Silva-Espinoza (2), M. Camacho-Casas (1), A. R. ISLA-RUBIO (2)
(1) Campo Experimental Valle del Yaqui-CIRNO-INIFAP; (2) Centro de Investigación en Alimentación y Desarrollo, A.C.

The proteins are the most important components of the flour of wheat by the capacity that they have to form a viscoelastic dough when they are mixed with water. The rheological tests are some of the tests to predict functionality of wheat flours. They must like objective study the physical properties of the gluten formed by the action of the kneaded one. In programs of genetic improvement of wheat, besides of evaluating the agronomic characteristics of wheat is necessary to evaluate the potential of wheat flours to determine its end-use. In this work 12 flours of experimental wheat were evaluated. Rheological measurements were made with the National Mixograph and the Texture Analyzer TA-XT2 with the Kieffer extensibility rig. The relative amounts of mono- and polymeric proteins were determined by SE-HPLC extracts obtained with buffer-SDS. The bread was prepared according to the direct method and loaf volume was determined by rapeseed displacement. Significant differences in protein composition of flours, dough strength (g)and extensibility (mm) of the obtained dough of different flours were observed

P-174
Rheological behavior of defatted maize germ-wheat flour blends
M. NASIR (2), M. Butt (2), M. Sharif (2), M. Sultan (2), M. Siddiq (1)
(1) Department of Food Science and Human Nutrition, Michigan State University, East Lansin, MI, USA; (2) National Institute of Food Science & Technology, University of Agriculture, Faisalabad, Pakistan

Exploring unconventional foods having good nutritional profile is the dire need of time due to the increasing demand for cheap dietary recourses, particularly in countries facing food scarcity and for the people with low income. Defatted maize germ (DMG) with nutrient dense composition is one of the examples of unconventional food sources which, is currently destined as animal feed. Defatted maize germ was grinded in to flour and sieved to remove the course fibrous materials. DMG flour was blended by partially replacing wheat flour at 5, 10, 15, 20 and 25% levels with DMG flour. Water absorption, dough development time and dough stability drawn from farinogram made on Brabender Farinograph depicted that DMG flour level in blends has a significant (P < 0.05) influence on all these parameters. Water absorption and dough development time increased while dough stability decreased with the increased augmentation level of DMG flour. Farinographic water absorption increased from 61.04% to 86.63% while an increase in dough development time was 4.73% to 7.08% with 25% of DMG addition level. Apparent viscosity was more at higher level of DMG fortification in flour blends and same trend was obtained at all suspension levels of 5, 10, 15and 20 percent of flour in distilled water. The force-deformation curve was recorded for doughs prepared at 60% water level from different flour blends by SMS Texture Analyzer. The control dough had a hardness value of 7.56 N, which increased significantly to 84.6N, when the DMG flour level increased up to 25%. The stickiness also increased significantly from –0.372 N to –4.610 N when the DMG level was 25% in the dough. It is evident from the results that the increased water absorption may result in increased yield of the finished product and less gluten thus, it may be successfully incorporated in products where extensibility of finished product (i.e. cookies) is not needed.

P-178
Stress relaxation behavior of wheat flour dough as a function of water content and extruded cranberry bean flour addition
R. RAVI (1), J. Harte (1), K. Dolan (2), A. Tanojo (1)
(1) Dept. of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, USA; (2) Dept. of Food Science and Human Nutrition and Dept. Biosystems and Ag., Michigan State University, East Lansing, MI, USA

The objectives of this study were to characterize the stress relaxation behavior of wheat flour dough as affected by the water content and extruded cranberry bean flour. Beans have been noted specifically for their ability to lower blood cholesterol, glucose, and homocysteine levels and to elevate dietary fiber and blood antioxidant levels. Cranberry flour addition improves the protein content and nutritional quality of the foods by improving the fiber, non digestible starches, vitamins, and minerals contents. Stress relaxation technique would provide valuable information on the dough behavior under various processing conditions like flattening, sheeting and rolling. The study was conducted by varying the a) water content (50–60%), b) raw cranberry bean flour and c) extruded cranberry bean flour, at 10, 20 and 30% levels using a texture analyzer (TA-XT2i) under 10% strain levels. The stress relaxation decaying constants k1 (initial decay rate) and k2 (asymptotic value of the normalized force) were obtained by linearising and plotting ‘relaxation time’ against ‘F0t/[F0-F(t)]’. The constants 1/k1 →0 relates to elastic solid and1/k2→1 indicates for a liquid. An increase in water content in the dough decreased the k1 values and increased the initial compressive strength. Both k1and k2 constants were significantly affected by the addition of raw and extruded Cranberry flour addition. The extent of stress relaxation (ESR)constant calculated from the force recorded after 1 min from the peak, increased from 25.36 to 28.13% when the raw bean flour addition from 10 to30% respectively, on the other hand the same increased from 31.07 to 37.58%for extruded bean flour. Similar increasing trends were also observed for peak force of dough for raw as well as extruded bean flour added doughs. These findings would help in predicting the behavior of dough under various processing conditions and consequently on the final product quality (cookie)including texture and consumer acceptability.

P-180
Qualities of dough and bread made from rice with various starch properties
N. AOKI (1), T. Umemoto (1), Y. Suzuki (1)
(1) National Institute of Crop Science, Tsukuba, Ibaraki Prefecture, Japan

Starch consists of two kinds of glucose polymer, amylose and amylopectin. The amylose content and amylopectin chain length distributions differ among rice cultivars. It is known that these starch properties affect quality of the cooked rice. The objective of this study is to evaluate how the starch properties affect qualities of the breads made with rice flour. Ten rice cultivars with various starch properties, including high, middle, and low amylase contents or amylose extender (ae) were used in this study. Dough was made from mixture of eighty grams of rice flour and twenty grams of wheat gluten(both are 14% moisture basis). Dough volumes, loaf volumes, amylase contents, amylopectin chain lengths distributions, protein contents, and damaged starch contents were measured. The dough development became higher with the decrease of damaged starch content in flour. However, those of ae mutants were low in spite of its low damaged starch content. Correlations were not observed among the dough development, amylase content and protein content. Interestingly, the rice with higher ratio of amylopectin short chains (S type) gave higher dough volume development than the rice with lower ratio of short chains (L type). Although there was no correlation among loaf volume, amylose content or protein content, loaf volume was negatively correlated with damaged starch content except aemutants. Bread hardness was positively correlated with amylose content, but not with protein content. The bread hardness was highest with the bread made from the rice with L type amylopectin. These results showed that damaged starch content is one of the most important factors responsible for rice dough and bread qualities, and that amylose contents and amylopectin chains affect bread hardness, but rice protein does not affect dough and loaf properties.

P-184 (likely)
The change of physicochemistry of 4 Japonica rice cultivars on milling ratio
Y. OH (1), C. Lee (1), K. Lee (1)
(1) CJ Cheiljedang Corporation, Seoul, Korea

Traditionally, millers standardize only whiteness of rice when they mill for cooked rice. So there is no consideration about nutrients loss and texture of rice, and over-milling is done with frequency. This study examined how the nutrients and texture change due to the milling ratio, and would help that millers find the proper ratio balancing between whiteness and other physicochemical properties. Four korean japonica rices well known as good taste were milled with 0.8% mass ratio interval from 92% to 89.6% to brown rice. The amounts of protein and lipid decreased according to the fall in milling ratio of white rice to brown rice, but the whiteness - L value tested by spectrophotometer increased. RVA viscosity was analyzed using powder of milled rice. Peak viscosities and breakdown viscosities increased slightly according to the fall in milling ratio. Texture analysis were studied with cooked rice. TA (texture analyzer) tested hardness and stickiness of cooked rice. Stickiness of cooked rice increased according to the decrease of milling ratio, but hardness decreased. The above results show that overall properties of stickiness or glutinosity grow strong according to the decrease of protein and lipid content induced by increase of milling ratio, but hardness decreases.

P-192
Evaluation of isolated emmer and einkorn starches
G. HAGHAYEGH (2), R. Schoenlechner (1)
(1) Department of Food Science and Technology, University of Natural Resources and Applied Life Sciences, Vienna, Austria; (2) Department of Food Science and Technology, Zabol University, Zabol, Iran

Emmer and einkorn were one of the earliest domesticated forms of wheat. Today they are only seldom cultivated. To increase the variety of raw materials old crops are now rediscovered and analysed for potential uses in food processing. To characterise isolated emmer and einkorn starch the main components and the functional properties were analysed. Starch was isolated from emmer and einkorn in pilot scale by using the tabeling method. Theamylose (Megazyme testkit), protein (Kjeldahl) and fat (Soxleth) content of the starch was measured. The functional properties water binding capacity, swelling power, solubility and transmittance (spectrophotometer) of the starch and the freeze-thaw stability (freezing starch gels at –7°C overnight, thawing at 30°C for 2 h, four cycles), viscosity (Brabender viscograph) and hardness (Texture Analyser TA-XT2i®) of emmer and einkorn starch gels were analysed. The amylose content was higher in einkorn starch than in emmer starch. The protein and fat content of emmer starch was lower, suggesting that the cleaning and isolation process was more successful than in einkorn starch. Isolated emmer starch showed a higher solubility, a higher water binding capacity but a lower swelling power compared to einkorn starch. The freeze thaw stability of einkorn starch was higher as shown by lower syneresis values. The peak viscosity, viscosity at 30 and 95°C and the setback profile of einkorn starch was higher than that of emmer starch. The transmittance of the einkorn starch gel decreased faster than that of the emmer starch gel during 5days. The hardness of the emmer starch gel was higher at the first day than that of the einkorn starch gel. The increase of the hardness during one week storage at 4°C was higher in the einkorn starch gel.

P-206
Differences in functional properties of starches between hard and soft wheat genotype
H. CHOI (1), B. Baik (1)
(1) Washington State University, Pullman, WA, USA

Gelatinization, pasting and retrogradation properties of starch significantly affect processing, cooking and textural quality as well as shelf life of many wheat-based food products. Amylose content of starch depends mainly on the genetic background of wheat and is largely responsible for variation in functional properties. To explore the differences in gelatinization, pasting and retrogradation properties of starches between wheat classes, we isolated prime starches from wheat genotypes of contrasting classes, including regular and partial-waxy starch endosperm, hard and soft, white and red, and winter and spring wheat, and determined their pasting properties using a micro-viscoamylograph, syneresis during storage and hardness of gel. Six partial-waxy wheat genotypes exhibited lower pasting temperature and greater peak viscosity than 12 genotypes of regular starch. In wheat genotypes of regular starch, starch pasting temperatures of four hard white (HW) wheat genotypes ranged from 83.4 to 85.7°C, while those of seven soft white (SW) wheat genotypes ranged from 79.2 to 82.9°C. SW wheat genotypes, with the exception of one SW genotype, were lower in peak viscosity of starch than HW genotypes. Similarly, in genotypes of partial-waxy starch, three SW wheat genotypes exhibited lower pasting temperature (69.2–76.6°C) and smaller peak viscosity (201-236 BU) than three HW wheat genotypes, which had pasting temperature and peak viscosity of 78.0–80.1°C and 246-261 BU, respectively. In both regular and partial-waxy genotypes, hard white wheat exhibited greater peak temperature than hard red wheat genotypes, while differences in peak viscosity between white and red wheat genotypes were inconsistent. Syneresis and hardness of starch gel stored for 7 days at 4°Cvaried widely among genotypes, but the differences between hard and soft wheat genotypes were not significant. Starches of regular amylose content showed much greater syneresis and hardness of starch gels than partial-waxy starches, which ranged from 1.51 to 7.18% and 15.5 to 23.0 N in the former, and from 0.20 to 0.57% and 12.1 to 15.8 in the latter, respectively.

P-214
The affect of low-amylose starch properties on tortilla quality
K. L. WHITNEY (1), S. Simsek (1), W. Berzonsky (1)
(1) North Dakota State University, Department of Plant Sciences, Fargo, ND, USA

The largest component of wheat flour is starch, and properties of the starch affect wheat flour tortilla quality. Flour from seven genotypes of wheat grown at three separate North Dakota locations as well as commercial flour samples were analyzed for their starch properties and tortilla quality. Genotypes studied were Alsen, Glenn, Lolo, NDSW 0481, Parshall, Penewawa, and Reeder. All are hard spring wheat genotypes, and NDSW 0481 has low amylase starch. Starch was isolated from the flour samples, and the physicochemical properties were correlated with tortilla quality. Tortillas made with the low-amylose flour had unique handling and storage properties, which related to the starch composition of the flour. These tortillas were very moist and sticky after baking and very elastic and extensible on the day of production. Low-amylose flours likely absorb more water as indicated by their high farinograph absorptions. During storage the low-amylose tortillas became more leathery, less extensible, and the force needed to stretch the tortillas increased greatly. The physical characteristics of these tortillas were also affected by the starch properties. The low-amylose tortillas tended to be thin, with a larger diameter, and they had a lower specific volume than the other tortillas. The color of the low-amylose tortillas tended to be more yellow than the other tortillas. The yellowness of the low-amylose tortillas was evident from visual comparisons. These results demonstrate that NDSW 0481flour has potential to improve tortilla quality if it is blended with flour from other spring wheat varieties.

P-217
Investigating the effect of dough prepartion using hot water and pregeleatinized starch on tortilla quality
F. XIE (1), B. Seabourn (2), M. Tilley (2), R. Chen (2)
(1) Kansas State University, Manhattan, KS; (2) USDA Grain Marketing and Production Research Center, Manhanttan, KS

One of the traditional ways to make “Lao Bing”, a Chinese tortilla-like flatbread, is to mix dough in which one-half of the added water is heated up to60–800C. The product is preferred due to its softness, but the reason for this increased softness is unknown. Our hypothesis is that addition of hot water gelatinizes part of the starch, which could hold more moisture, and hence increase the softness. The objective of this study was to determine if pregelatinized (pre-g) starch could improve tortilla quality. A complete randomized block design was applied. Tortillas were made using a commercial tortilla flour with the addition of 0%, 10%, 20%, and 30% pre-g starch. To examine the effects of hot water on tortilla quality, tortillas were prepared using the commercial flour and 50% of the total water at 75°C.Samples were kept in plastic ziplock bags at room temperature immediately after cooling. Rollability test was conducted on day 1, 7 and 14 of storage and samples were rated on a 1–5 scale with 5 as best. Stretchability (maximum force (MF) and distance) was analyzed on day 0, 1, 7, and 14 after baking using a Texture Analyzer (TA-XT2, Texture Technology Corp., Scarsdale, NY). At least 6 replicates were tested for rollability and 12 were tested for stretchability. The control had the lowest rollability compared to the others at all time points. At day 14, the rollability of the 30% pre-g was 3.85, which was1.71 times of that of the control. MF of all the samples was about the same at day 0 and increased during storage. However, the 30% pre-g had the lowest rate of increase. On day 14, the control had the highest MF, which was 1.5time of that of the 30% pre-g. The results indicated that pre-gelatinized starch could improve tortilla quality. Increasing water temperature could easily gelatinize starch and hence improving tortilla quality with minimal cost. This method would largely benefit the commercial tortilla producer.

P-219
Leavening and temperature effect on tortilla physical properties
L. M. WINSTONE (2), S. J. Mulvaney (1), P. Rayas-Duarte (2)
(1) Cornell University, Ithaca, NY, USA; (2) Robert M. Kerr Food & Ag Products Center at Oklahoma State University, Stillwater, OK, USA

Tortillas are the second most popular bread type in America, according to results of the 2002 State of the Tortilla Industry Survey. Having cornered 32%of the sales for the U.S. bread market, tortillas trail white bread by only 2%.Challenges in meeting consumer demands for new and lower fat tortillas have included negative effects on the machine-ability and quality of the products. Four treatments and control tortillas were processed at a commercial scale facility. The treatments included: 1) 0.3% leavening and 315°F, 2) 0.3% leavening and 390°F, 3) 1.2% leavening and 315°F, and 4) 1.2% leavening and390°F. Physical properties of tortillas included strength, roll-ability and blister scores. The tortillas for all treatments were stronger and more extensible than the control group. On average, the treatments produced tortillas with 32%higher force and 26% longer distances before they ruptured. After 4 days of storage at about 25°C, tortillas from all treatments including the control had roll-ability scores of 5 on a scale of 1–5 with 5 meaning no cracks or breakage. Treatment 1 had 87% less blister spots than the control treatment which represented a lower temperature group. Treatments 3 and 4 had approximately the same amount of blistering as the control group but treatment 2 had 65%more blisters. The transparency of tortillas from treatment 1 was about twice that of the other treatments. Common food service industry practice of warming tortillas in a steam cabinet often promotes surface stickiness, but no surface stickiness was observed after 1 hour with saturated steam at 100°C.Properties of tortillas stored for up to one month will be discussed

P-221
Investigating the textural properties of starch gels treated with iodine
S. DHILLON (1), K. Seetharaman (1)
(1) University of Guelph, Guelph, Ontario, Canada

The goal of our research is to use iodine as a tool to understand the structural, architectural and functional behaviour of starches from different botanical sources. The objective of this study was to investigate the effects of different levels of iodine on the textural properties of Corn (CS), Waxy Corn (WCS),Potato (PS), Waxy Potato (WPS) and Wheat (WS) starches. Iodine at different concentrations ranging from 0.1% to 2% dry starch basis were added to starch(8% db) in a RVA at room temperature or at 95°C. Gel firmness was measured following storage at room temperature (RT) for 1 day and following 7 days at refrigeration by using a TA.XT Plus Texture Analyser. Both the waxy starches remained a viscous paste and did not form a gel even after 7 days of storage at all treatment levels. For the normal starches, as expected, the gel firmness increased with time for both the control and treated gels. Furthermore, gel firmness in the treatments where iodine was added at 95°C was lesser than the corresponding RT treatments due to the additional water introduced during the treatment. However, significant differences were observed in gel firmness of normal starches following different treatments. The highest level of iodine concentration where gel formation was observed was different for different starches at RT and at 95°C. PS was able to form a gel at 5x and20x iodine concentration at RT and 95°C, respectively, compared to the other starches. Furthermore, the extent of staling of the gels treated with iodine was different for the different starches as well. These observations suggest that despite the similar amylose contents of the starches from different botanical sources, there was dissimilarity in the gel formation and retrogradation. This can be associated with the contrasting pasting properties of these starches as a function of the granular architecture, and the differential extent of polymer leaching and the ability of the starch polymers to bind iodine.

A comparison of the effect of selected oils and fats on the final volume and physical properties of bread and puffed pastries
M. Abu-Hardan (1), S. E. HILL (1)
(1) University of Nottingham, UK; Cereal Foods World 52:A33

Fats play an important role in many aspects of baked products. The growing preference for non-hydrogenated fats stimulated this study examining the potential of vegetable oils and their fractions in the manufacture of baked products. Breads and flaked pastries were made without additional lipid or with butter, soybean oil, palm oil and fractions of palm oil. The samples produced with butter had the highest expansions. There were no significant differences for the volumes between the samples prepared with palm oil, mid fraction, stearine and the soybean oil. These oils were all significantly better, in terms of volume of product, than palm olein, which in turn was only 3% better than the non-oil control. The expansion was therefore not correlated with the solid/fat ratios. Investigation of the bubble formation showed the greatest number of bubble cells per unit area to occur in the palm stearine loaves and the smallest number in the soybean sample. The palm mid faction had the largest cell diameter and palm oil the smallest. Bread staling was investigated by change in texture and calorimetry, where the results showed changes after one day and continuing retrogradation throughout the next four days of storage (at ambient temperature and in sealed containers). The recrystallisation endotherms showed little dependence on the oil type. However, though the hardnesses of the samples were not significantly different after baking, significant differences were apparent after four days of storage. The butter and palm oil samples were softer than the other breads. The hardest stored samples were those containing no oil or the palm olein. As it was hard to obtain the plasticity necessary to layer the solid fats for making flaked pastries, the palm oil was tempered at ambient for 24 hours. The layered pastries then expanded by a similar amount to those made with butter.

Handling properties of cereal materials in the presence of moisture and oil
M. Abu-Hardan (2), L. Young (1), S. E. HILL (2)
(1) Stable Micro Systems, UK; (2) University of Nottingham, UK; Cereal Foods World 52:A33

The final quality of baked materials can depend on their initial mixing and handling behaviour. The particle size and shape, as well as water content and ingredients will govern material flow. A powder flow analyzer attached to a Texture Analyser (Stable Micro Systems, UK) was used to compare the flow behaviour of four cereals systems: maize and wheat (in both starch and flour forms), as functions of particle size and distribution, water content and the addition of different types of oil. It was expected that the smaller the particle size the higher the tendency to stick (because of less free volume between the particles), but that was not the case. The results showed that wheat starch, with a bigger particle size than maize starch, had higher cohesion properties and as water content increases the cohesion increases by the same magnitude. Caking strength for both starches was influenced by the water content; in particular at 30% water content (w/w), neither cohesion nor caking indices could be measured for wheat starch because of the high stickiness of the particles. Although the two flours had particles of very similar sizes, with differences in the distributions only, maize showed higher cohesion indexes compared to wheat flour, these values decreased with increasing water content. The caking property for maize was not significantly affected by water content with values of approximately 100 ± 5. The caking strength increased for wheat flour from 8 to 500 as moisture increased from 12.5 to 30%. Generally cohesivity and cake forming ability were affected by the physical state of the oil i.e. by solid/liquid ratios. Wheat starch showed the greatest packing and cohesive behaviour, with and without the oil. Maize flour exhibited the weakest packing and cohesive properties.

Dough physical properties and bread making performance of flours from four Mexican wheat varieties
P. A. Alvarado-Felix (1), A. R. ISLAS-RUBIO (1), M. A. Camacho-Casas (2), M. G. Salazar-Garcia (3), M. Granados-Nevarez (1), F. Vasquez-Lara (1), T. L. Maldonado-Parra (1)
(1) CIAD, A.C.; (2) INIFAP-CIRNO; (3) Universidad de Sonora; Cereal Foods World 52:A34

Flours from four Mexican wheat varieties grown during the 2005–2006 cycle, at the INIFAP-Yaqui Valley Experimental Station located in Ciudad Obregon, Sonora, were analyzed for moisture, protein and ash content. Dough physical measurements with the National Mixograph, Chopin Alveograph, and Texture Analyzer TA-XT2 were performed. Bake test was also carried out for each variety. Among varieties, Rayon presented the shortest mixograph development time (4.2 min), statistically different (P < 0.05) from Kronstad and Tacupeto varieties. According to the Alveograph test, Tarachi and Rayon were significantly less extensible and presented the lowest G and W values than Tacupeto and Kronstad. There was no difference (P > 0.05) on tenacity among the varieties; however, differences in P/L and P/G ratios were observed, indicating that Tarachi had the most unbalanced gluten. Dough maximum resistance (Rmax) and extensibility measured with TA-XT2 varied from 29.8 to 61.1 g-cm, and 4.5 to 7.4 cm, respectively. Rayon showed the highest Rmax and almost doubled the Rmax value of the other varieties. The highest bread volume (235.7 cm(^3)) and specific bread volume (5 cm(^3)/g) was obtained from Kronstad flour, being only significantly different from Tarachi flour. Flours from Kronstad and Rayon showed a better bread-making gluten.

Effects of protein-modifying enzymes on the structure and shelf-stability of flour tortillas
J. ALVIOLA (1), R. Waniska (1)
(1) Texas A&M University, College Station, TX, USA; Cereal Foods World 52:A34

Effects of protease and transglutaminase (TG) on dough and tortilla structures, and on shelf-stability were determined to infer the role of gluten in tortilla production and storage. Confocal microscopy was used to study the effects of the enzymes on dough and tortilla microstructure. Control and treated tortillas were prepared using standard procedures in a pilot-plant scale hot-press and gas oven, and evaluated for texture properties and shelf-stability after 0.04, 1, 3, 7, 14 and 21 days. Micrographs of control dough had thin protein strands forming a continuous, web-like matrix. Protease-treated dough had pieces of proteins in place of the continuous matrix, while TG-treated dough had thicker protein strands that were heterogeneously distributed. Control tortillas had a well-developed and well-distributed continuous protein structure. Protease-treated tortillas had a continuous structure despite being composed of hydrolyzed proteins in the dough, while the TG-treated tortilla retained clumps of proteins. Protease-treated tortillas required the least force, distance and work to rupture. Tortillas prepared with protease and TG broke on the third and seventh days of storage, respectively, while the control broke after two weeks using the subjective rollability evaluation. Both protease (hydrolyzing enzyme) and TG (cross-linking enzyme) weakened dough and tortilla structures. Thus, it appears that at least a moderate gluten network is necessary to impact a longer retention of tortilla flexibility during storage.

Effect of incorporation of bean (Phaseolus vulgaris L.) flour on some physical and nutritional properties of wheat flour tortillas
A. A. ANTON (2), R. Fulcher (3), O. M. Lukow (1), S. D. Arntfield (2)
(1) Cereal Research Centre, Agriculture and Agri-Food Canada, Winnipeg, MB, Canada; (2) Department of Food Science, University of Manitoba, Winnipeg, MB, Canada; (3) University of Manitoba, Winnipeg, MB, Canada; Cereal Foods World 52:A14

Composite flours containing varied levels (15, 25, and 35%) of bean (navy, black, pinto, and red) and wheat flours were made into tortillas. Farinograph results showed increased water absorption and increased mixing tolerance index as bean concentration increased. Firmness and cohesiveness were evaluated using a Texture Analyzer (TA-XT2). Significant changes in texture were observed in tortillas containing different levels of bean flour, however, the effect of bean variety was insignificant. Similarly, diameter, thickness and rollability indicated acceptable bean tortillas at 25% substitution. Except for navy bean tortillas, bean addition had a significant impact on color. Nutritionally, all bean tortillas had significantly higher levels of crude protein, total phenolics and antioxidant activity. Protein content of formulations containing beans ranged from 12.29 to 14.38%, demonstrating that even at the lowest concentration, bean tortillas were 13.6% richer in protein than the control (10.98%). Phenolics ranged from 62.67 to 157.75 mg of ferrulic acid eq/100g of sample, with the highest levels found in tortillas substituted with 35% of red and pinto bean flours. This parameter was positively correlated with antioxidant activity (r = 0.90), confirming the importance of colored beans in the prevention of oxidative stress. Based on the overall analyses, flour tortillas containing 25% bean flour have good sensory properties, thus representing a new opportunity for the functional foods market and adding value to bean crops.

Evaluation of alternative heat sources to cook maize tortilla
G. ARÁMBULA-VILLA (1), E. Gutiérrez-Arias (1), M. A. Piña-Martínez (2), I. Gúzman-Acosta (2)
(1) CINVESTAV IPN. Unidad Querétaro. Querétaro, Qro. México; (2) Universidad Tecnológica de San Juán. San Juán del Rio, Qro. México; Cereal Foods World 52:A34

A main step in the elaboration of maize tortilla is the baking. Since its beginning, the mud “comal”, heated with direct fire, was used to cook the nixtamalized maize masa. The mud comal was changed by the metal comal later. The baking stage of maize tortillas elaboration process has not had important changes. Today, tortillas machines, which consume gas L.P. are used. In this work, tortillas elaborated by the traditional method and cooked in an infrared furnace (IR) with different times and cooking temperatures, and in a microwaves (MW) stove with times of 50, 55 and 60s, were tested and compared with cooked tortillas on comal heated with L.P. gas. Puffing degree, color parameters (L, a, b), tensile strength and cutting force tests were determined. The moisture content of tortillas elaborated with MW was very low (32%, w/w), and the appearance and rheological properties were poor quality. Tortillas elaborated with traditional and lR methods were similar and their quality characteristics (color, texture and puffing degree) were very good. Base on results we concluded that the IR method is one of the best alternatives for the maize tortilla elaboration.

Rice individual kernel breaking force and hardness index distributions and the relationship to milling quality
R. C. BAUTISTA (1), T. J. Siebenmorgen (1), R. M. Burgos (1)
(1) University of Arkansas; Cereal Foods World 52:A15

The objective of this study was to investigate rice individual kernel breaking force and hardness index distributions and their correlations to milling quality. Specifically, the goal was to correlate the percentage of strong kernels (kernel with breaking force greater than 20 N) and kernel hardness index to head rice yield as a possible indicator of milling quality. To accomplish this goal, rice varieties/hybrids Bengal, Cheniere, Cocodrie, Francis, Wells, and XP723 were harvested at various harvest moisture contents from Arkansas, Mississippi, and Missouri in 2004 and 2005. Samples were cleaned and gently dried at 20°C and 56% RH to approximately 12% MC, then analyzed for kernel breaking force, hardness index, and HRY. For breaking force measurements, 200 rough rice kernels were randomly selected from each sample lot and manually-dehulled to produce brown rice. Individual kernel breaking force of brown rice kernels was measured using a texture analyzer (TA.XT2i, Texture Technologies Corp., Scarsdale, NY) with a flat-faced loading head, having a thickness of 1.48 mm and a width of 9.9 mm, and a loading rate of 0.5 mm/s. For kernel hardness index, 300 rough rice kernels were randomly selected from each sample lot. Individual kernel hardness index of rough rice was measured using a single kernel classification system (SKCS 4100, Perten Instruments, Springfield, IL). Individual kernel breaking force and hardness index distribution trends among varieties/hybrid were discussed. Results indicated a generally good correlation (R = 0.81) between HRY and percentage of strong kernels across varieties/hybrids tested. Average kernel breaking force and kernel hardness index showed weak correlations with HRY across varieties/hybrid; however, a linear trend existed between the average breaking force/hardness index and head rice yield.

Effect of edible film coating on lipid oxidation inhibition, moisture retention and hardness improvement of Korean traditional cookie (Yackwa)
Y. S. CHO (2), G. J. Han (2), K. B. Song (1)
(1) Chungnam National University, Daejeon, South Korea; (2) National Institute of Agricultural Science and Technology, Suwon, South Korea; Cereal Foods World 52:A38

Effect of edible film coating on lipid oxidation inhibition, moisture retention and hardness improvement of Yackwa (Korean traditional cookie) manufactured by deep fat frying was investigated. The Yackwas were prepared by conventional method in Korea and coated with corn zein (CZ), soy protein isolate (SPI), hydroxypropyl methyl cellulose (HPMC) or methylcellulose (MC), respectively. Uncoated samples were used as control. All of the samples were stored at 60(C for 2 weeks. and moisture content, acid values, peroxide values and hardness of samples were measured at intervals of 2 days. The moisture contents in Yackwas coated with various edible films were higher than those of control during storage. Also acid and peroxide values of coated samples were lower than those of control. No significant differences in hardness of coated samples and control were observed. CZ and SPI coatings were more effectiveness in reducing moisture loss and acid value and peroxide value of Yackwa than HPMC and MC ones during storage at 60(C for 2 weeks. These results showed that protein–based edible coating is useful as means for moisture retention and reduction of lipid oxidation of Yackwa during storage.

Jatropha curcas L. flour addition to wheat flour doughs and their effects rheological properties
R. Cruz-Villegas (2), J. Martínez-Herrera (1), S. Soto-Simetal (2), E. Perez-Soto (2), A. Hernández-Soto (2), M. Reyes-Santamaria (2), J. Hernandez-Chavez (2), N. N. GUEMES-VERA (2)
(1) CEPROBI-IPN Carr.Yautepec-Jojutla Km 8.5. Col. San Isidro. Yautepec, Morelos, Mexico; (2) ICAP-UAEH-Tulancingo, Hidalgo, México; Cereal Foods World 52:A39

The purpose of this investigation was to study the effects of added Jatropha curcas L. flour into wheat flour to prepare fortificated dough on protein content and dough rheology. Total protein content according AOAC (1995); dough extensibility, adhesiveness and texture profile analysis test were conducted using a texture analyzer (TA-HDi). Wheat-J. curcas mixture dough making were prepared with wheat flours (WF) fortifying with various levels (Jc: 5.0, 10.0, 15.0 and 20.0%). The protein content for J. curcas was 63.3%, the extensographs showed that, increasing the J. curcas flour percentage from 0% to 20%, the dough were less extensible as indicated by higher ratios of R50/Ex, while the area under the curve (i.e. the energy required to break the strength of dough) increased substantially by adding up to 5% Jatropha flour. This indicates that the dough of the blends are still strong and elastic. However, when the amount of Jatropha flour was increased up to 100%, the dough became very weak and the stability and development time decreased as well as the extensibility and the resistance. The adhesiveness decreased particularly in samples prepared with 20 and 100% of Jatropha flour. The presence proteins produced a decrease in the firmness and consistency of the dough and an increase its cohesiveness, which favours the production of a high-quality product.

Pre-cooked fiber-enriched wheat flour obtained by extrusion: Functional, nutritional and baked product sensory properties
H. Gajula (1), S. ALAVI (1), K. Adhikari (1), T. Herald (1)
(1) Kansas State University, Manhattan, KS; Cereal Foods World 52:A41

Foods with high fiber can reduce calorie uptake and provide health benefits linked to obesity, and chronic ailments like diabetes and cardiovascular disease. However, inclusion of fiber diminishes the final product quality and consumer acceptability of cereal products. The overall objective of this project was to produce fiber-enriched (0, 10, 20 and 30% wheat bran) pre-cooked wheat flours using extrusion processing (at mild and high shear and temperatures) in order to enhance their nutritional value, while maintaining functional and sensory properties in baked products such as cookies and tortillas. For all flours, as % bran increased, RVA peak viscosity (RVA-PV) and Mixograph peak height (M-PH) decreased by up to 46% and 38%, respectively, with the exception of mildly processed flour with 20% bran that had higher RVA-PV and M-PH as compared to 0% bran. At all bran levels, RVA-PV and M-PH were significantly lower for pre-cooked flours as compared to uncooked flours. The quality of cookies (weight and spread factor) and tortillas (specific volume, rollability and extensibility) from both pre-cooked and uncooked flours deteriorated progressively as % bran increased, with a greater negative effect of pre-cooked flours as compared to uncooked flours. Soluble dietary fiber increased by 20–45% and insoluble dietary fiber decreased by 25–35% in pre-cooked flours as compared to uncooked flours at corresponding bran levels. Consumer acceptability results showed that pre-cooked flour products were comparable in overall liking to uncooked flour products. Extrusion pre-cooking did not lead to enhancement in functional properties of fiber-enriched flour or quality of cookies and tortillas. However, pre-cooked flours had higher soluble dietary fiber level as compared to uncooked flours, and also resulted in cookies and tortillas of comparable consumer acceptability.

Plasticizers effects on mechanical properties of oat starch films
M. GALDEANO (1), M. Grossmann (1), S. Mali (1)
(1) Universidade Estadual de Londrina, Londrina, Paraná, Brazil; Cereal Foods World 52:A41

Oat starch films were prepared by casting using glycerol, sorbitol, glycerol: sorbitol (1:1) mixture, urea and sucrose as plasticizers. The effects of these plasticizers were investigated on mechanical properties of films stored at different (11, 57, 76 and 90%) relative humidities (RH). The plasticizers did not affect significantly (P < 0.05) the equilibrium moisture content of oat starch films, except at 90% RH, at which condition films without plasticizer adsorbed less water. In general, a decrease in stress at break and Young’s modulus and an increase in strain at break were evidenced when RH increased in all film formulations. Films without plasticizer, in all RH values, showed higher stress at break values than plasticized ones and presented strain at break stable at different RH conditions. Sucrose plasticized films were more fragile than others at low RH conditions probably because the bulky-ring of its structure difficult the interaction with starch chain molecules compared to straight chains of the other plasticizers.

Buckwheat in wheat flour tortillas
M. GRITSENKO (1), N. Alviola (1), L. Rooney (1), R. Waniska (1), C. McDonough (1)
(1) Cereal Quality Laboratory, Department of Soil & Crop Sciences, Texas A&M University, College Station, TX, USA; Cereal Foods World 52:A42

Buckwheat (Fagopyrum esculentum) is a pseudo-cereal grown in Eastern Europe and Asia. Its proteins have good distribution of essential amino acids, such as lysine and tryptophan. These proteins have high solubility and nutritional value. Buckwheat contains dietary fiber, vitamins (B1, B2, B3) and minerals (P, Ca, Fe), resistant starch, rutin and D-chiro-inositol. Rutin is an antioxidant in buckwheat with desirable properties for treatment of chronic heart disease and varicose veins. D-chiro-inositol occurs in relatively high levels in buckwheat. It might reduce levels of sugar in the blood and have applications in diets of people with type II diabetes. Whole buckwheat was ground into buckwheat flour that was blended with wheat flour to produce press type flour tortillas containing 5, 10 and 20% buckwheat. Tortillas containing buckwheat flour were darker; the 10% blend had an attractive color with a pleasant aroma, and taste. Rollability of the fresh tortillas decreased slightly from 5 to 4.5 for the tortillas containing 0 and 20% buckwheat flour respectively. Distance to rupture and force to rupture were 14, 8 and 7.5 for the control and 17.1 and 7.5 for the tortillas containing 20% buckwheat flour. In 4 days force to rupture did not significantly change. Rupture distance decreased to 12.6 mm for the control and to 12.2 for the tortillas containing 20% buckwheat flour. After 4 days, the rollability decreased slightly to 3.5, 3.5, 2.4 and 3.0 for the control, 5, 10 and 20% buckwheat tortillas, respectively. The modifications in composition and in vitro starch hydrolysis and estimated glycemic index will be measured.

Tortilla quality and antioxidant properties of flour tortillas with tannin sorghum bran and brown flaxseed
D. GUAJARDO-FLORES (1), N. Alviola (1), C. M. McDonough (1), R. D. Waniska (1), L. W. Rooney (1)
(1) Texas A&M University, College Station, TX, USA; Cereal Foods World 52:A42

The flour tortilla market continues to grow and become popular in the U.S. Consumption of whole grains or products containing healthy ingredients are increasing. Two ingredients that contribute natural sources of dietary fiber, antioxidants and color include tannin sorghum and brown flaxseed. Inclusion of bran into baked products increases a healthy perception, but often changes the texture of products. Therefore, the goal of this study was to analyze the effect of the addition of tannin sorghum bran with stabilized and ground whole brown flaxseed on antioxidant properties and texture properties during storage in flour tortillas. Antioxidant activity, phenol content, subjective tortilla rollability and objective texture measurements using the 3D extensibility method were evaluated in flour tortillas with different levels of tannin sorghum bran (0%, 5%, 10%) combined with 5% whole ground flaxseed. Color (CIE L*a*b* scale) was measured 24 hours after baking. Texture was evaluated using the TA.XT2i Texture Analyzer (Texture Technologies Corp., Scarsdale, NY/Stable Micro Systems, Godalming, Surrey, UK) using a 3D extensibility method. The addition of flaxseed and bran significantly darkened the tortillas in each successive treatment. After day 1 there was no significant difference in rupture force and modulus values between treatments. Control tortillas retained flexibility longer than the other treatments; tortillas with 10% bran had cracks after eight days of storage, while the control lasted 16 days without cracking. Treatments containing 10% and 5% sorghum bran with 5% flaxseed had higher values for phenols and antioxidant activity and the lowest L values. Tannin sorghum bran and brown flaxseed provided natural color with higher antioxidant capabilities than control treatment.

Whole grain barley and oat breads enriched with soluble fibers
Y. KIM (1), W. Yokoyama (1)
(1) USDA, ARS, WRRC, Albany, CA; Cereal Foods World 52:A47

Barley and oat beta-glucans are recognized to reduce risk of heart disease. Whole grain consumption is also associated with decreased risk of chronic metabolic disease. In order to increase the consumption of whole grain barley and oat we have developed breads made up entirely of their flours enriched with 3–6% of soluble cellulose, a form of soluble dietary fiber. Soluble cellulose, hydroxypropylmethylcellulose (HPMC), is a linear glucose polymer of beta-1,4 linkages and related to the cereal mixed beta-1,4-beta-1,3 linkages. Like cereal beta-glucans they have been shown to reduce plasma cholesterol in published clinical studies. In addition to its healthful properties, soluble celluloses are a necessary substitute for the gas trapping protein, gluten, that is lacking in barley and oat. Nonwaxy barley bread enriched with 5% HPMC had twice the loaf volume compared to barley flour alone. The hardness, gumminess, and chewiness by TPA were decreased with HPMC addition. Sensory characteristics of barley and oat breads were compared to whole grain wheat bread. Formulations for waxy barley breads enriched with HPMC were also developed. Substitution of HPMC for gluten results in whole grain breads with reasonable loaf volumes, good texture and a 100% increase in soluble dietary fiber content.

Evaluation of the effects of Lupin derivatives on the quality of cookies
H. López-López (2), S. Soto-Simental (2), M. Reyes-Santamaria (2), E. Perez-Soto (2), A. Hernandez-Fuentes (2), J. Hernandez-Chavez (2), G. Davila-Ortiz (1), A. Sanchez-Tototsaus (3), N. GUEMES-VERA (2)
(1) ENCB-IPN D.F. México, México; (2) ICAP-UAEH Tulancingo Hidalgo Mexico; (3) Instituto Tecnologico de Estudios Superiores de Ecatepec de Mexico; Cereal Foods World 52:A51

Mexico has serious nutritional problems, due low income of the population. Thus, this research will be contribute diminish that nutritional problems. The aim of the present work was to characterize the dough texture, adhesiveness and extensibility of cookies fortified with derivatives of Lupinus. A proximal analysis was developed. After that dough was prepared with Wheat Flour (WF) fortified with various levels of Lupin Flour (LF) (8, 12 and 20%), Lupin Protein Concentrate (LPC) (10, 20 and 30%) and Lupin Protein Isolate (LPI) (5, 10 y 15%). Later the rheological analyser (TPA, adhesiveness and extensibility) were performed by using a TA-HDi texture analyzer (Stable MicroSystems Ltd, Surrey, UK) in a compression mode. The chemical composition of the flour was 6.5% protein for WF and 39.4% protein for LF, 66% protein for LPC and 89.1% for LPI. The cookie fortified with 12% of LF and 20% of LPC had 8.4 y 9.7% protein respectively as compared to 6.4% in the regular product, which agreed with other results reported in the literature. The addition of 12 and 20% produced a decrease in the firmness and consistency, and an increase in the cohesiveness of the dough. Generally speaking, higher amounts of precipitate (30%) did not significantly affect the firmness, consistency or cohesiveness of the dough. The adhesiveness increased particularly in samples prepared with 20 and 15% of LF and LPI respectively. The presence of Lupin derivatives produced a excellent firmness and consistency of the cookies and an increase in its cohesiveness, which favours the production of a high-quality product.

A technological approach to reducing salt in bread
E. J. LYNCH (1), M. M. Moore (1), E. K. Arendt (1)
(1) Department of Food and Nutritional Sciences, University College Cork; Cereal Foods World 52:A23

High sodium intake may raise blood pressure, increasing the risk of heart attack and/or stroke. The average salt (NaCl) consumption in the western diet is 11 g person/day, 75% of which is obtained from processed foods with bread products contributing to at least a quarter of dietary sodium intake. In this study, doughs and breads containing levels of salt from 0% to 1.2% (the latter representing the average salt level found in Irish bread) were investigated. Intermediate values were chosen to include those which may carry the nutritional claims associated with low sodium diets. Standard baking tests, i.e. bake-loss (BL), specific volume (SV), moisture loss, texture analysis, and digital image analysis (DIA), were performed. Salt caused a linear increase in the resistance to extension (RE) of the dough as measured by Extensiograph and Kieffer cell. The gaseous retention coefficient significantly decreased at low NaCl levels. Rheological evaluation showed that lower salt doughs have higher viscoelastic moduli and complex viscosity. The reduction in salt resulted in a slight decrease in BL and SV of the baked breads. Five-day staling trials revealed that bread with 0% NaCl had excessively high hardness values when compared to all other samples. Loaf volume increased with lower salt addition. DIA, combined with Scanning Electron Microscopy (SEM), showed that the presence of salt induces a larger number of smaller air cells. In conclusion, the results of this study show that breads produced at low salt levels are not physically different when compared to “standard” breads, even though the doughs display different behaviours. The 0.3% is a salt level that produces larger volume bread that is structurally optimum according to DIA and SEM, and deems that optimisation of this formula will allow the production of low salt bread that is suitable to industrial processing.

Variation in grain hardness and associated traits in USA barley breeding lines
S. NAIR (1), S. E. Ullrich (1), B. Baik (1)
(1) Department of Crop & Soil Sciences, Washington State University, Pullman, WA, USA; Cereal Foods World 52:A53

Despite increasing interests in nutritional benefits of consuming barley food products, we have limited experience in systematic breeding and cultivation of appropriate barley varieties for food uses. Identification of food use traits of barley and establishment of screening methods are crucial for development of food barley varieties. Barley grain hardness may influence pearling and milling properties, flour particle size and eventually processing and product quality, as is intensively documented in wheat. Grains of 959 breeding lines of various classes contributed by ten major barley breeding programs in the USA as part of the USDA funded barley Coordinated Agricultural Project were evaluated for hardness using a single kernel characterization system (SKCS). Hulls of the hulled barley types were removed by abrasion before the SKCS test. Average kernel weight and diameter of barley grain ranged from 24.9 to 53.7 mg and from 1.7 to 2.9 mm, respectively. Hulled barley lines exhibited wider variation in kernel weight and diameter than hulless lines. Spring and winter lines were similar in distribution of kernel diameter and average values. The proportion of hull, as determined by the abrasive removal rate, ranged from 10.2 to 20.8%. The proportion of hull was <15.5% in 99% of winter lines and 80% of spring lines. Grain hardness ranged from 30 to 92 in hulled barley and from 42 to 91 in hulless barley. Eighty percent of winter and 30% of spring barley lines exhibited >67 in hardness. Average kernel hardness was 71 for winter and 62 for spring types. Large variation in hardness and other grain characteristics among barley classes and genotypes indicate the potential for the identification of genes or quantitative trait loci (QTLs) and of genetic markers for development of barley varieties possessing appropriate grain characteristics for food uses.

Production of bread enriched with commercial starch high in resistant starch
S. OZTURK (1), H. Koksel (1), P. Ng (2)
(1) Department of Food Engineering, Hacettepe University, Ankara, Turkey; (2) Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, USA; Cereal Foods World 52:A56

Resistant starch (RS) offers an exciting new potential as a food ingredient. It has been shown to possess physiological benefits similar to dietary fiber. The current work investigates the incorporation of three different commercial starches (Hylon VII, Novelose330 and CrystaLean), known to be high in RS content, into bread formulation at three different addition levels (10, 20, and 30%) and evaluates their effects both on the properties and RS content of the breads. Bread samples were prepared according to AACCI Method 10-10B (AACC International 2000) using a hard wheat variety. Bread-firmness (N) and bread-quality parameters (crust color, crumb color, crumb cell structure and external appearance-symmetry) were determined. RS contents of commercial starch, flour and bread samples were measured using the Megazyme RS Kit according to Approved Method 32-40 (AACC International 2000). Starch-supplemented doughs were weaker and absorbed more water than doughs made from the base flour. RS contents of starch-supplemented breads increased significantly as the starch addition level increased. The commercial starches used did not have substantial deteriorative effect on crumb color values, external appearance, nor on symmetry of bread loaves. The starch-supplemented breads had better crumb cell structure than the control bread at 10 and 20% addition levels for each starch sample. Crust color values decreased at 30% addition level for Novelose and CrystaLean and above 10% addition level for Hylon VII supplementation. Loaf volumes of the breads decreased above 10% level for Novelose and above 20% level for Hylon VII and CrystaLean supplementation. Firmness of the breads increased above 10% level for Novelose and above 20% level for Hylon VII and CrystaLean supplementation.

The relationship between different biotypes and protein composition of hard red winter wheat flours and their affect on alkaline noodle color and texture
S. PARK (1), M. Tilley (1), S. R. Bean (1), B. W. Seabourn (1), R. A. Graybosch (2)
(1) USDA-ARS GMPRC; (2) USDA-ARS Grain, Forage, and Bioenergy Research Unit; Cereal Foods World 52:A57

Twenty-five samples of biotypes derived from two hard red winter wheat (HRW) cultivars, Centurk and OK102, were grown in a randomized complete block design at Mead, NE. The biotypes varied in their high molecular weight glutenin subunit (HMW-GS) composition with five different HMW-GS allelic combinations present across the samples (2*, 7 + 8, 2 + 12; 2*, 7 + 9, 2 + 12; 2*, 6* + 8*, 3 + 12; 2*, 6* + 8*, 5 + 10; and 2*, 7 + 9, 5 + 10). These lines were selected to determine the relationship between HMW-GS and protein composition on color and texture of alkaline noodles. Protein composition, including insoluble polymeric protein (IPP), soluble polymeric protein (SPP), gliadin, and albumin and globulin (AG) was found to vary significantly between the various HMW-GS combinations. Flour protein content was not significantly different between the various sets, however. For mixograph mixing time, 83.6% of the variation among the samples was explained by HMW-GS composition, while 89.0% of the mixing tolerance variation was. Most noodle color traits were not significantly affected by HMW-GS groups except for a and b values at 24 hr after production. For cooked noodle texture, water uptake was significantly affected by HMW-GS groups but cooking loss was not. Noodle texture profiles including hardness, springiness, chewiness, resilience, cohesiveness, and adhesiveness were significantly affected by HMW-GS types. Overall protein composition was significantly correlated with noodle texture: SPP % was positively correlated with hardness (r = 0.83, P < 0.0001) and negatively with springiness (r = –0.77, P < 0.0001), resilience (r = –0.76, P < 0.0001), and adhesiveness (r = –0.44, P < 0.05), whereas IPP% was negatively correlated with hardness (r = –0.74, P < 0.0001). Protein composition was also significantly correlated with cooking water uptake and noodle color.

Cooked rice hardness and stickiness as affected by grain composition and structure of leached materials during cooking
J. PATINDOL (1), X. Gu (1), Y. Wang (1)
(1) University of Arkansas; Cereal Foods World 52:A58

Cluster, correlation, and multivariate regression analyses were used to rationalize the effects of grain chemical composition and leached material fine structure on cooked rice texture by studying 23 U.S. long-grain cultivars. Cooked rice hardness and stickiness were measured with a texture analyzer. The amylose-amylopectin ratio (AAR) of the leached material during cooking was determined by high-performance size-exclusion chromatography. Amylopectin fine structure was characterized by high-performance anion-exchange chromatography with pulsed amperometric detection. Head rice composition was evaluated in terms of apparent amylose content, crude protein and surface lipids. Among the physicochemical variables evaluated, AAR was found to be an important determinant of cooked rice hardness and stickiness. Soft-cooking, high-amylose cultivars (e.g. Jodon and L-202) leached out more amylopectin than amylose (AAR<1). Dry-cooking, high-amylose cultivars (e.g. Newrex and L-205) leached out more amylose than amylopectin (AAR>1). Cultivar differences in leaching behavior were attributed to variations in apparent amylose content, crude protein, and amylopectin chain length distribution.

Effect of high molecular weight glutenin subunits (HMW-GS) on wheat flour tortilla quality
V. PIERUCCI (1), M. Tilley (2), R. Graybosch (3), K. Tilley (1)
(1) Kansas State University; (2) USDA-ARS GMPRC Manhattan, KS, USA; (3) USDA-ARS Lincoln, NE, USA; Cereal Foods World 52:A58

Tortillas are the most popular non-bread wheat based product. Flour used in tortilla production has been typically optimized for bread making. The flour properties that determine good quality bread do not necessarily provide good quality tortillas. In this study, the influence of high molecular weight glutenin subunits (HMW-GS) was investigated on tortilla quality. Two biotypes derived from the hard red winter wheat cultivar Centurk were used, which contained the following HMW-GS: 2*, 7 + 9, 2 + 12 and 2*, 7 + 9, 5 + 10. The flours were paired according to protein content of 10.02% (2 + 12) and 9.92% (5 + 10) in Group 1 and 10.30% (2 + 12) and 10.42% (5 + 10) in Group 2. Tortillas were prepared in a laboratory scale and analysis was carried out at days 0, 2, 4, 7 and 14. Diameter, rollability and textural properties using the TA-TX2 Texture Analyzer were determined. Tortilla diameter was statistically larger in tortillas made from low protein flour containing HMW-GS 2 + 12 (P > 0.05) among the four conditions. Independently of the protein content used, flour with subunits 5 + 10 showed a better overall rollability than flour with subunits 2 + 12. Texture analysis revealed no difference in tortilla stretchability among the flours. However, the Rupture Force (Fr) of tortillas was affected by flour protein content. When lower protein content was used, Fr was greater for tortillas made with HMW-GS 2 + 12, conversely, when higher protein content was used, Fr was greater for tortillas made with HMW-GS 5 + 10. These results indicated better tortillas were obtained with higher protein content flours containing HMW-GS 5 + 10.

Effect of lyophilized jumbo squid (Dosidicus gigas) fin and mantle muscle on dough properties and bread making performance of a commercial wheat flour
J. C. RAMIREZ-SUAREZ (1), A. R. Islas-Rubio (1), L. Montoya-Ballesteros (1), M. Granados-Nevárez (1), F. Vasquez-Lara (1), R. Pacheco-Aguilar (1), M. E. Lugo-Sanchez (1)
(1) CIAD, A.C.; Cereal Foods World 52:A60

The effects of adding 2.5 and 5% of lyophilized jumbo squid (Dosidicus gigas) fin (JSF) and mantle muscle (JSM) on dough properties and baking performance of wheat flour were studied. Dough maximum resistance to extension (Rmax), extensibility (Ext), and deformation work (Area) at 45-min resting time were evaluated with a texture analyzer TA-XT2. Baking performance was evaluated by the straight dough baking procedure using 35 g of flour. Loaf volume was measured by the rapeseed displacement method. Acceptability of bread loaves was evaluated by an untrained sensory panel. Addition of 2.5% JSF tripled (P < 0.05) Rmax vs. control dough (i.e. 118.9 ± 6.4 vs. 40.6 ± 6.3), while 5% addition either JSF or JSM double it (P < 0.05). Ext decreased (P < 0.05) by addition of lyophilized powders. As animal protein was increased Ext decreased (i.e., 6.6 ± 0.5 for control vs. 4.0 ± 0.1 and 2.7 ± 0.2 for 2.5 and 5% JSF respectively; JSM showed similar results). However, 2.5% JSF or JSM addition increased Area (P < 0.05) 2.4 and 1.8 times that of control, respectively. Specific loaf volume (loaf volume/loaf weight) showed no significant (P > 0.05) difference vs. control; however, an inverse relationship was observed as animal protein was added. Sensory results showed that samples with lower level of addition were very close to control, suggesting this concentration (2.5%) could be used for this type of product.

Effect of processing conditions on tortilla texture
J. H. RATHOD (1), J. L. Kokini (1)
(1) Rutgers, The State University of New Jersey; Cereal Foods World 52:A60

Tortilla texture is an integral component of tortilla quality. In fact, it governs consumer acceptance of tortilla products. To understand the effect of processing conditions on tortilla texture tortillas were prepared using different combinations of dough resting times (10 and 20min), baking temperatures (350 and 450°F) and cooling times after baking (2, 5 and 10min). Objective texture analyses were performed based on the tortilla burst rig test using a TAXT2i texture analyzer. The force and distance to break, toughness and elasticity were measured by the Texture Expert Exceed™ software and used as indicators of ultimate failure properties. Results were reported for a minimum of 10 replicates. Tortillas baked at a higher temperature (450°F) showed higher tortilla rupture force as compared to a lower temperature (350°F). Lower dough resting time (10 min) was found to increase tortilla rupture force. A dough resting time of 10 min showed higher tortilla resilience compared to 20 min. Tortillas with a resting time of 20 min showed reduced toughness. Increasing tortilla cooling time increased the rupture distance and toughness. A baking temperature of 450°F increased the value of the gradient for tortillas as compared to 350°F. Appreciation of the relation between tortilla texture and process parameters is important to produce the most desirable tortilla products. This understanding will give manufacturers the ability to create tortillas with the most favorable characteristics.

Effect of storage time and temperature on tortilla texture
J. H. RATHOD (1), J. L. Kokini (1)
(1) Rutgers University; Cereal Foods World 52:A60

Texture affects the consumer acceptance of any food product. Storage time and temperature determine the freshness of all food products. In this study we tried to measure the effect of storage time and temperature on tortilla texture. Tortillas were prepared using the modified Bello et al method. Samples were packaged and stored at three different temperatures: room temperature (22 ± 1°C); freezer temperature (-19 ± 1°C); and refrigeration temperature (3 ± 1°C). Samples were analyzed after 5 days, 20 days, one month and 2 month of storage. TAXT2i texture analyzer was used to measure extensibility, tensile force and gradient value of tortillas. Tortillas stored at lower temperatures were thawed at room temperature (22 ± 1°C) for 5 hours before testing. Minimum of ten tests were performed and the results were reported. Extensibility was highest when tortillas were stored at freezer temperature. An increase in storage temperature and time showed reduced extensibility. Tortillas retrograded within 5 days when stored at room temperature. The extensibility value showed a sharp decline after one month of tortilla storage at freezer temperature. The force required to extend tortillas was lowest for tortillas stored at freezer temperature and highest for tortillas stored at room temperature. The rupture force value increased with extent of storage. Tortillas stored at freezer and refrigeration temperatures retained freshness which reflected with lower rupture force values. The gradient value increased with an increase in temperature and extent of storage. Highest gradient value was observed for tortillas stored at room temperature for 2 months. This tortilla self life study will help tortilla industry to select best tortilla storage conditions. It will also help them to predict the changes in tortilla texture with respect to storage time and temperature.

Effect of addition of gums and polyols on tortilla stickiness
J. H. RATHOD (1), J. L. Kokini (1)
(1) Rutgers, The State University of New Jersey; Cereal Foods World 52:A60

Tortilla stickiness is undesirable for the tortilla and the food service industry. Difficulty in separating individual tortillas affects the consumer acceptance of these products. We have devised strategies to reduce the stickiness and surface energy of flour tortillas by adding GRAS ingredients. Tortillas were prepared with a variety of GRAS ingredients that favorably compete for water. Xanthan gum, carboxymethylcellulose (CMC), glycerol and propylene glycol were added individually and in combination to the tortillas. Instrumental stickiness of tortillas was measured using the TAXT2i texture analyzer. These results were linked to the surface chemistry of tortillas by contact angle measurements (VCAoptima Dynamic Contact Angle and Surface Tension System). We used differential scanning calorimetry (DSC) to determine the freezable water present, mechanical spectroscopy to characterize the phase behavior, and wide-angle x-ray scattering (WAXS) to understand the effect of crystallinity. Addition of gums and polyols, alone and in combination, to the formula made the dough more pliable and machinable. Tortillas containing gums and glycerol showed increased water retention, decreased water activity, and low freezable water. Addition of glycerol significantly reduced the water activity from 0.94 to 0.91. A lower glass transition temperature was observed when tortillas were made using polyols. Addition of gum and glycerol showed a reduction in the surface free energy, mainly the polar component, and reduced instrumental stickiness in tortillas. Understanding the effect of the addition of gums and polyols in controlling tortilla stickiness will provide the tortilla industry with new and useful tools to formulate and produce flour tortillas with reduced stickiness.

Effect of processing conditions on tortilla stickiness
J. H. RATHOD (1), J. L. Kokini (1)
(1) Rutgers, The State University of New Jersey; Cereal Foods World 52:A60

Tortilla stickiness is an undesirable attribute. Our goal was to understand the effect of processing conditions on tortilla surface energy and stickiness. To evaluate the influence of processing conditions on stickiness, tortillas were prepared using different combinations of dough resting times (10 and 20 min), baking temperatures (350 and 450°F) and cooling times after baking (2, 5, and 10 min). Instrumental stickiness of tortillas was measured using the TAXT2i texture analyzer. These results were linked to the surface chemistry of tortillas by contact angle measurements (VCAoptima Dynamic Contact Angle and Surface Tension System). We used differential scanning calorimetry (DSC) to determine the freezable water present, mechanical spectroscopy to characterize the phase behavior, and wide-angle x-ray scattering (WAXS) to understand the effect of crystallinity. A higher dough resting time allowed the dough to retain more moisture and subsequently increased the water activity and stickiness in tortilla. More freezable water was found in tortillas with a shorter dough resting time (10 min). Higher baking temperature, dough resting time and tortilla cooling time showed reduced relative crystallinity in tortilla. Tortillas baked at 450°F had higher total surface energy, mainly the polar component, and were stickier than tortillas baked at 350°F. A cooling time of 5 min was found to be more effective in controlling tortilla moisture content. Tortillas cooled for 5 min after baking had the lowest surface energies and were less sticky compared to tortillas cooled for 2 and 10 min. Recognizing the effect of processing conditions on tortilla stickiness will offer the tortilla industry novel and practical processing methods.

Physico-chemical, and thermal properties of maize varieties and their relation to the dry and wet milling performance
L. Rodriguez (1), J. VELES (2), R. Gomez (3), J. Figueroa (2), M. Gaytan (2)
(1) ITO, Av. Tecnologico No. 1. Orizaba, Veracruz, Mexico; (2) Cinvestav del I. P. N. Libramiento Norponiente No. 2000 Fracc. Real de Juriquilla Queretaro, Mexico; (3) UAEH, Av. Universitaria Km 1, Ex. Hacienda Acuezalpa Rancho Universitario Tulancingo, Hidalgo. C. P 43600, Mexico; Cereal Foods World 52:A62

Corn is the most important food crop for subsistence farmers in Mexico. It is consumed in its original, unfractionated condition as whole meal for porridge, as popped corn, as tortillas after lime treatment, and as snacks among many corn products. Recent high corn prices have forced the dry- and wet-milling and daily industries to look domestic suppliers of corn and starchy grains. The farmers of State of Hidalgo in Mexico grow exotic maize varieties, either for domestic food or animal feed but some of those corn races have the potential to be used by the dry- and wet-milling industry. The objective of this work was the evaluation of maize varieties with good dry and wet milling performance. The samples were 45 corn genotypes of white, yellow and blue kernel color. Most of the white corn showed hard kernel and high to intermediate endosperm content with excellent performance for the dry milling. The material showed poor water absorption suitable for snacks production. The blue corn showed soft and very soft kernel with high endosperm content with high starch yield and can be suitable for the tortilla flour industry that require pigmented products. Functional and thermal properties were also evaluated and will be discussed related to specific components of the kernel (starch, protein, oil, fiber and solubles) and potential uses.

Effects of gluten proteins on cooking properties, textural properties and ultrastructure of Chinese raw noodles
R. SAINI (1), P. Ng (1), J. Steffe (1)
(1) Michigan State University; Cereal Foods World 52:A63

The objective of this study was to evaluate the effect of gluten proteins on the textural profile analysis (TPA) parameters, stress relaxation properties by Texture analyzer TA-XT2 and on ultrastructure of noodles as observed by Laser Scanning Confocal microscope (LSCM). Two wheat varieties, Caledonia and NuHorizon, which differ in protein content, protein quality and noodle making properties, were selected. The wheat flour samples were fractionated into starch, gluten and water-soluble fractions. The fractions were used to obtain reconstituted flours with different protein contents (6.5, 8, 9.5, and 11.5%). Noodles were prepared from these reconstituted flours and tested for their cooking properties, texture and ultrastructure. Cooking data showed that increasing the protein content of the samples decreased the yield of cooked noodles and cooking loss. As protein content was increased, the hardness, gumminess and chewiness of the samples increased, adhesiveness was decreased, and cohesiveness was increased. Springiness and resilience of the samples did not show any definite trend. Stress relaxation data also showed that the F(max) at 20% strain was highest with the maximum protein content of the flour sample. The LSCM z-sectioning and the quantification of proteins by Pascal software showed definite increase in the amount of protein matrix in the noodle samples as the amount of protein was increased. No other significant differences were observed with LSCM of the samples. Overall, both Caledonia and NuHorizon showed similar behavior with increases in protein content.

Functional properties of wheat and sorghum flour blends for cookies
M. SINGH (1), A. Mohamed (1)
(1) USDA/ARS/NCAUR; Cereal Foods World 52:A65

Sorghum is an important cereal crop grown in many developing countries that is potentially suitable for use in composite flours for baking. Earlier studies on the use of sorghum flour in cookies resulted in grittiness, which was attributed to the particle size of sorghum flour. The objective of this study was to investigate the effect of particle size on the pasting characteristics of composite flours and its baking quality. Sorghum flour was fractionated into two particle sizes (greater than 0.18 mm, and less than 0.18 mm). Water holding capacity was higher for coarser particle size sorghum flour that the finer sized. The pasting characteristics of starch from the fractionated and unfractionated sorghum flours varied considerably. The peak viscosity and final viscosity was lower for starch from coarser particle size sorghum flour than that from finer particle size sorghum flour. The farinograph quality number for fractionated sorghum flour blended with all purpose flour (wheat) at 0, 10, 20, and 20% levels increased significantly with increasing levels of sorghum flour and was higher for the coarser particle size fraction in comparison to the finer particle size fraction and the unfractionated sorghum flour. The cookies made with finer particle size sorghum flour blended with wheat flour were softer than those made from the coarser particle size sorghum flour wheat flour composites. The color of the cookies was significantly affected by the particle size and the amount of sorghum flour in the blends. The cookies made with fractionated sorghum flour blends were lighter and among those with finer particle size blends had lighter color on the top of the cookies.

The incorporation of brewer’s spent grain as a source of dietary fibre in breadmaking
V. STOJCESKA (1), P. Ainsworth (1), A. Plunkett (1)
(1) MMU-Department of Food and Tourism Management, Manchester, UK; Cereal Foods World 52:A66

Brewer’s spent grain (BSG) is a main by-product of the brewing industry and contains a high level of dietary fibre. The effect of the addition of BSG into bread and its effect on the textural and nutritional properties have been studied. Dried and milled BSG at levels of 10–30% with particle sizes of 0.25 and 0.5 mm were added to the dough mix. A number of experiments have been studied: farinogram characteristics (dough development time, stability and degree of softening), water absorption, protein and fibre content, loaf volume, textural characteristics and colour of bread crumbs and crust and image analysis of bread slices (cell structure and slice dimensions). The results showed that addition of BSG decreased the loaf volume of baked bread, water absorption, stability time, degree of softening, area of bread slices and height, number and area of bread cells and holes while increased dough development time, content of protein and fibre. There was not a significant effect on hardness of the bread crumb and crust at higher level of BSG. Lightness and yellowness in crumb and crust were negatively affected by the higher level of BSG while crumb redness was positively affected and crust redness negatively. Different particle sizes of BSG had no effect on the quality of baked bread.

Effect of whole barley flour on the stability of flour tortillas
M. WALKER (1), A. Toma (1), M. Omary (1)
(1) Cal Poly Pomona University, Pomona, CA, USA; Cereal Foods World 52:A69

Wheat and whole barley tortillas with and without preservatives were packaged in re-sealable LDPE/LLDPE bags and placed under room temperature and refrigeration for 13 and 25 days, respectively. Tortillas were periodically analyzed for changes in texture, color, water activity, pH, aerobic plate count (APC), and yeast and molds (YM). Tortillas without preservatives (NP) stored at room temperature and those with preservatives (WP) at both temperatures showed an increase in rupture distance (extensibility) overtime (P > 0.05). However, tortillas NP stored under refrigeration had an initial increase in rupture distance but remained constant thereafter. Tortillas NP showed no changes in lightness (L), redness (a) or yellowness (b) under refrigeration. Conversely, L and b increased while a remained constant at room temperature. Tortillas WP showed a decrease in L and b, and an increase in a at both temperatures. Water activity increased in tortillas NP stored at both temperatures, but it remained constant in tortillas WP stored at both temperatures. The pH of both tortilla types was constant at the studied temperatures with the exception of tortillas NP stored at room temperature, which showed an initial increase followed by a decrease overtime. Tortillas NP stored under refrigeration and tortillas WP stored at both temperatures displayed no growth in APC. However, tortillas NP showed a 3 log increase in APC at the end of the storage period at room temperature. Tortillas NP at room temperature showed a steady increase in YM, while the same tortilla type increased to <100 cfu/g on day 25. In contrast, tortillas WP at both temperatures showed no increase in YM overtime. Shelf-lives of 25 days and less than 48 h were observed for tortillas at refrigeration and room temperature, respectively. These results show promise to storing wheat and whole barley tortillas without preservatives under refrigeration.

Effect of pentosans and pentosanase on the baking quality of hard spring wheats grown under diverse conditions
M. WANG (1), G. R. Carson (1)
(1) Canadian International Grains Institute, Winnipeg, MB Canada; Cereal Foods World 52:A69

Total pentosans (TP), water-extractable pentosans (WEP), water-unextractable pentosans (WUP), and ratio of WEP to WUP were determined for wheat samples of the Canada Western Red Spring and the Canada Western Hard White Spring grown in 2003 (warm, dry, and well-matured) and 2004 (cold, wet, and late-matured) crop years. Baking quality of the wheat samples was evaluated with and without the additions of two commercial pentosanase preparations (xylanase I, xylanase II). The TP contents were lower and ratios of WEP to WUP were higher in the samples of 2003 crop than those in the 2004 crop. Addition of the two pentosanases improved the bread-making performance of all wheat samples and retard the process of bread firming over one week period. It was found, however, that the degree of effectiveness of pentosanase depended on crop year and wheat class. Both enzymes exhibited a larger improvement in specific loaf volume and less effect on bread firmness in the 2004 crop than in the 2003 crop. No significant correlation was found between the rate of bread firming and the natural pentosan composition/content of the flour samples. The practical application of the knowledge of wheat pentosan and pentosanase generated in this study will be discussed.

A rapid small-scale method to evaluate dough viscoelastic properties
F. XIE (1), B. Seabourn (2)
(1) Kansas State University; (2) USDA Grain Marketing and Production Research Center; Cereal Foods World 52:A69

Dough viscoelastic properties are of special interest to bakers and wheat breeders. Dough extensibility (DE) and resistance to extension (RE) influence each step of the baking process as well as product end-use quality, and thus are important quality factors to consider in wheat breeding programs. The objective of this study was to develop a rapid small-scale method to evaluate dough DE and RE properties. A total of 20 hard red winter wheat flour samples varying in protein content (8.9–14.3%), Farinograph optimum water absorption (55.8–68.0%), Farinograph dough development time (4.5–23 min), and Farinograph mixing tolerance (7.0–59.8 min) were studied. Doughs were mixed to optimum at optimum water absorption by Farinograph. The standard Extensigraph method (AACCI approved Method 54-10) was compared to a small-scale method which utilized the Texture Analyzer (TA) equipped with a Kieffer rig. Correlation of determination (R(^2)) of DE measured by Extensigraph versus by TA was 0.77, while that of RE measured by each instrument was 0.46. The potential of near-infrared reflectance spectroscopy (NIR) for measuring DE and RE was also investigated. The NIR technique showed great potential in predicting both DE and RE as determined by Extensigraph. The highest R(^2) was 0.84 for DE and 0.81 for RE, with a standard error of prediction of 49.34 and 9.66, respectively. Spearman rank correlation coefficients of DE and RE predicted by the Extensigraph-based model and TA-based model were 0.97 and 0.68, respectively. Results show that these two model’s ability to differentiate DE was similar.

Dough extensibility ranges on U.S. winter wheat cultivars and advanced lines
P. YEAP (2), S. J. Mulvaney (1), P. Rayas-Duarte (2)
(1) Cornell University, Ithaca, NY, USA; (2) Oklahoma State University, Stillwater, OK, USA; Cereal Foods World 52:A70

Selecting for lines with balanced dough strength and extensibility properties can be challenging in wheat breeding programs since universal molecular markers have not been clearly identified. While in spring wheat one report of recombinant inbred lines showed a negative correlation of strength and extensibility, this relationship has not been systematically analyzed in U.S. winter wheats. Forty three winter wheat cultivars and advance breeder lines were analyzed for extensibility and mixing properties, wet gluten, gluten index, SDS sedimentation, bake test and HMW-GS allelic composition. The range values of micro-extensibility properties were Rmax mean 0.22 N (range 0.10-0.24 N), extensibility at Rmax 71.3 mm (53.8-85.0 mm) and area to Rmax 8.1 N.mm (4.2-11.9 N.mm). Three allelic combinations represented about 47% of the total frequency but they did not correlate with the extensibility properties. Partial correlation adjusted for protein variation showed a positive relationship of dough strength and extensibility (r = 0.67, P < 0.01) in the samples analyzed. All extensibility parameters were correlated to mixograph mix time and farinograph peak time; Rmax, r = 0.72, Extmax, r = 0.44, and area at Rmax r = 0.66; P < 0.01). Positive correlation of gluten index (P < 0.01) and negative correlation of wet gluten content (P < 0.05) with all extensibility parameters were obtained. The results suggest that current analytical methods are not successful in predicting baking performance, such as loaf volume, with large deformation extensibility tests. New approaches that are able to decouple elastic and viscous components during large deformation straining of dough may help in that regard.

Evaluation of stickiness in starch solutions
R. YGLESIAS (1), D. S. Jackson (1)
(1) Dept. of Food Science & Technology, University of Nebraska, Lincoln, NE, USA; Cereal Foods World 52:A70

Stickiness is a phenomenon that involves a bond between two surfaces that are placed in contact with each other. Starch stickiness is greatly impacted by water availability, temperature, and degree of cook. Solutions of corn starch in water w/w (8%, 16%, 24%, 32%, 40%, 48% and 56%) were prepared and heated in a 2L beaker from room temperature to 90°C in approximately 14 minutes. Samples were then split and stored in two different ways. While still warm, half the solution was stuffed into a 6.35 cm internal diameter casing and placed at –20°C for 12 hours. Samples were then thawed until they reached 25°C (12 hours) and cut with an electric knife to a 1.27 cm height. The remaining solution was placed in disposable Petri dishes and allowed to cool at room temperature until they reached 25°C (10 hours). Stickiness was measured using a TA-XT2i Texture Analyzer in Adhesiveness Test Mode. Water activity and DSC parameters were also determined in samples after storage. Stickiness significantly (P < 0.05) decreased as the starch concentration increased. Frozen and thawed samples had significantly (P < 0.05) lower stickiness values than samples cooled at room temperature. Warm samples were observed to be stickier at higher starch concentrations. This suggests that temperature also plays an important role in stickiness. DSC enthalpy J/g significantly (P < 0.05) increased as starch concentration increased. Starch at higher concentrations did not gelatinize completely, as water became limiting. Stickiness is a phenomenon that involves a combination of cohesive and adhesive forces. These forces are impacted differently by temperature, water availability, and starch degree starch cook.

Separation of plastic and elastic rheological behaviors of gluten and relationship to breadmaking performance
D. ZHAO (1), B. Allvin (3), P. Rayas-Duarte (2), R. Chinnaswamy (4), S. Mulvaney (1)
(1) Cornell University, Ithaca, NY, USA; (2) Oklahoma State University, Stillwater, OK, USA; (3) Perten Instruments AB, Huddinge, Sweden; (4) USDA GIPSA, Kansas City, MO, USA; Cereal Foods World 52:A72

Traditional instruments used to evaluate dough and/or gluten rheological properties do not provide unambiguous separation of elastic and viscous behaviors. Thus, it has been difficult to determine how pure elastic properties of gluten are related to breadmaking performance. Recovery after creep and cyclic large deformation tensile testing are two ways to decouple elastic and viscous effects. A large variation in the recoverable shear strain after preceding creep (7 to 28%) was seen for fifteen popular wheat cultivar glutens—prepared using the Glutomatic method—representing five US wheat classes. High recoverable strain was seen for both 2 + 12 and 5 + 10 hard wheat cultivars. The recoverable deformation ranged from 71 to 93% of the creep deformation, and the Zeleny sedimentation values ranged from 13 to 56 ml. However, the recoverable work dropped to <40% for these glutens when tested in a large deformation (500%) cyclic tensile test. The maximum force, residual deformation and patterns of the force-deformation curves also varied widely when these glutens were stretched in tensile mode. Comparison of the overall patterns of the creep-recovery results for gluten relative to several linear, amorphous synthetic polymers suggested that gluten lies in the rubbery flow region of viscoelasticity, which is characterized by viscous flow superposed over delayed elastic effects. Good to excellent test bake bread volume was obtained for several cultivars from this sample set. Apparently, optimized pup loaf breadmaking process can accommodate a fairly wide range of viscoelastic behaviors of glutens. This work defines those ranges objectively using creep-recovery and tensile testing.

S-80
Laboratory-scale sheeting and lubricated squeezing flow behavior of Asian noodle doughs. A. S. ROSS (1), J. B. Ohm (1). (1) Oregon State University, Corvallis, OR, USA.

Salt and alkaline noodle doughs were made from flours of 2 wheat varieties with contrasting dough attributes. Water addition was fixed at 34% and doughs were either rested for 45 min after compounding or processed without resting. Doughs were compounded through a 5 mm roll gap then reduced in thickness through gaps of 3.5, 2.45, 1.7, and 1.2 mm. Lubricated squeezing flow (LSF) rheometry with stress relaxation was performed on doughs between each roll pass. Dimensions of sheeted doughs were altered by flour source, formulation, and presence or absence of resting. Doughs from the weaker variety were significantly (all significance at P < 0.01) thinner across all treatments. Rested doughs were thinner than unrested doughs, but only at the first reduction pass. Differences in dough length were small and contingent on the treatment factors being compared. Proportional die-swell (PDS) after passing the roller nip was significantly higher for the stronger doughs across all treatments, and was significantly lower for rested doughs at the first reduction. However, PDS of rested doughs tended to equal or exceed that of unrested doughs in the final reduction pass. Alkaline doughs had significantly higher PDS, except for unrested doughs of the stronger variety where alkaline doughs had lower PDS. The LSF method allowed the observation of relaxation times (RT) for the doughs (time at constant strain for stress to decay to 1/e of peak stress). RT decreased with each roll pass in all treatments. This was most pronounced in the stronger doughs. RTs were somewhat shorter for the rested doughs in the first 2 or 3 reduction passes but equaled RT for the unrested doughs in the later reductions. RT was longer for alkaline doughs in all comparisons of salt and alkaline doughs with one exception. Other LSF factors are still being analyzed at the time of writing.

S-90
Texture of alkaline cooked corn masa products. H. ALMEIDA (1). (1) Kellogg Co., Battle Creek, MI.

Alkaline cooked corn masa products include mainly table tortillas and chips. Desirable tortillas are flexible, soft and shelf stable. Tortilla texture vary with grain cooking conditions, masa properties, baking conditions, puffing extent and moisture content. Desirable chips are crispy and crunchy. Chip texture is defined by masa properties, thickness, baking conditions, moisture content prior to frying and frying conditions. Texture of tortillas, chips and their intermediate products has been measured subjectively and more recently with instrumental procedures. Retention of cooked corn hulls with higher pH provides for additional flexibility and softness of fresh and reheated tortillas. Optimum cooking of corn to absorb lime and partially digest the hulls helps also. Glycerin and CMC provide softness to both fresh and stored tortillas. Thin chips, baked to minimal moisture, allowed to temper for moisture equilibration prior to frying and fried at high temperature for a short time develop a highly porous microstructure that delivers a crispy texture. Thick chips, baked to a high moisture, fried without tempering at lower temperatures for longer times develop a non-uniform more-continuous solid microstructure that are perceived as undesirably hard and crunchy. Optimal formulation and process combined with sensitive techniques are required for effective texture quality control that delivers appropriate, improved food for targeted consumers.

S-114
Puroindolines: Carbohydrate interactions. C. F. MORRIS (1), A. D. Bettge (1), G. E. King (2), M. J. Pitts (2), K. Pecka (3), P. Greenwell (2). (1) USDA ARS, Washington State University, Pullman, WA, USA; (2) Washington State University, Pullman, WA, USA; (3) University of Idaho, Moscow, ID, USA.

Wheat flour is the world’s most important bakery ingredient. Consequently there is a great need to more fully understand the factors that contribute to flour quality. One key quality factor results from the interaction of kernel texture (i.e. ‘hardness’) with milling, product formulation and processing. The two puroindoline proteins, ‘a’ and ‘b’, have been shown to confer the major classifications of kernel texture in wheat, i.e. soft, hard and durum. Here, we will describe the effects of the puroindoline proteins on grain, milling, flour quality and baking in closely related soft and hard winter wheat lines (“near-isogenic lines” or NILs). We will also describe research being conducted to measure the material properties, i.e. the textural differences, between soft and hard wheat kernels using endosperm “bricks” and the TA-XT2i. NILs ranged from 28–80 for NIR hardness, 27–69 for SKCS hardness, 62.2–69.1% for Quadrumat flour yield, 34.7–50.0% for Quadrumat break flour yield, 53.1–68.0% for alkaline water retention capacity, and 8.36–9.80 for cookie diameter. All ANOVA models (9 wheat lines, 5 environments, 2 reps) had good model fit (>0.93% R2). The endosperm bricks were prepared from individual wheat kernels using a special sanding device. Brick dimensions were obtained, then subjected to stress / strain analysis using a TA-XT2i. Grain lots for this study included Madsen and Alpowa soft white, ID377s and a hard Alpowa NIL as hard white spring, and Renville durum wheat varieties. Kernels of each were further segregated into vitreous and non-vitreous classifications. The detailed procedure and analysis of stress / strain data will be presented. Waxy (0 amylose) wheat also exhibits soft and hard grains and expression of puroindolines. Lastly, there is a significant difference ascribed to the combined action of puroindoline a and b on the adherence of remnant endosperm material to the surface of starch granules upon fracture. Scanning electron microscopy was used to document this difference which seems to result from the greater adhesion of endosperm material in the absence of fully functional puroindolines. This greater adhesion manifests itself as kernel hardness, which profoundly affects flour and baking quality.

S-129
An approach to standardize the instrumental texture determination of cooked spaghetti firmness. M. J. SISSONS (1), L. Schlichting (2), N. E. Egan (1), W. Aarts (2), B. Marchylo (2). (1) New South Wales Agriculture, Tamworth, NSW, Australia; (2) Canadian Grain Commission, Winnipeg, MB, Canada.

The firmness of cooked spaghetti is an important quality measure used in durum breeding and quality control laboratories throughout the world. While firmness is only one component of the textural characteristics of cooked pasta, it is one of the most common measurements obtained using instrumental and/or sensory evaluation. Although there is an instrumental method available (AACC 66-50), precise conditions for sample cooking and instrument testing are not well defined. In previous work, we have found that differences in the interpretation of the method as used by different laboratories, affects the ranking of the same unknown samples. In this paper, an analysis of the affect of varying the cooking procedure, sample presentation and instrument settings on cooked firmness, using 10 carefully selected spaghetti samples, will be presented. As a result of this analysis, a “standard method” was adopted and used to compare the firmness values of 30 diverse spaghetti samples in two laboratories. These results were also compared with firmness values obtained using methods based on AACC 66-50 in each laboratory. By using this carefully defined standard method, higher precision and improved reproducibility between laboratories was achieved.

O-9
Influence of the fatty acid on the baking activity of phospholipids. B. Fischer (1), P. KOEHLER (1). (1) German Research Center of Food Chemistry and Hans-Dieter-Belitz-Institute for Cereal Grain Research, Garching, Germany.

Due to common structural elements phospholipids act as emulsifiers. Therefore, those polar lipids, e.g. lecithin, which can be isolated on an industrial scale from plant sources, are used in improvers for breadmaking. The baking activity of whole lecithin is well known, however, very little information is available about the effect of the fatty acid present in phospholipids. Therefore, the aim of this study was to determine the influence of the fatty acid in phosphatidyl choline on the baking performance. A homologous series of phosphatidyl cholines with fatty acid chain lengths ranging from 6:0 to 20:0 including 18:1, and 18:2 was synthesized by reacting glycerophosphatidyl choline with the respective fatty acid anhydrides in the molten state. The synthetic phosphatidyl cholines were characterized by chromatography, 1H NMR, 13C NMR and mass spectrometry. The functional properties were determined by a micro-scale baking test and by micro-extension tests with 10 g of flour. The baking performance was best for dicaprinylphosphatidyl choline, which caused an increase of the loaf volume by 55%. Longer C-chains (12:0 to 20:0) and double bonds within the chains (18:1 and 18:2) had a less positive effect on the loaf volume (increase by up to 40%). For phosphatidyl cholines with short-chain fatty acids an optimal concentration of 0.2% based on flour weight was found, whereas higher concentrations were required for compounds with longer C-chains. Comparative studies with lysophoshatidyl cholines showed, that longer C-chains were required to get the best baking performance as compared to phosphatidyl choline. Additional rheological tests confirmed the differences between individual compounds and compound classes.

O-10
Role of liquid lamellae in gas cell stability in bread making. B. S. SROAN (1), F. MacRitchie (1). (1) Kansas State University, Department of Grain Science and Industry, Manhattan, KS, USA.

Bread volume is directly related to initial concentration of gas cells during mixing and stability of these gas cells during different stages of bread making. During mixing, gas cells are occluded and concentrated in the liquid phase of dough in the form of small nuclei. These gas cells expand during proofing and baking stages due to release of fermentation gases into them. During late proofing and baking, the liquid lamellae surrounding expanding gas cells act as secondary protection together with the primary gluten film, which may not be continuous at these stages. The objective of the study was to look into the role of liquid lamellae surrounding the gas cells in gas cell stability. The surface properties of the liquid phase of the dough are the result of surface active compounds (proteins and lipids) at the gas-liquid interface. The study also investigated how these surfactants affect gas cell stability. Contributions of the liquid film stability to dough expansion were assessed by baking tests using flours varying in their natural lipid content/composition. Lipids were analyzed by thin layer chromatography (TLC). Incremental addition of natural lipids back into defatted flour causes bread volume to decrease, and, after reaching a minimum, to increase. Polar lipids have beneficial effects on loaf volume whereas certain non-polar lipids such as linoleic acid have detrimental effects. Rheology of the dough varying in lipid content/composition was studied using a bubble inflation system mounted on TAXT-Plus texture analyzer. Lipids are found to have negligible effect on dough rheological properties such as strain hardening.

O-40
Technical and nutritional benefits of acacia gum in bakery and cereal based products. S. BARAY (1). (1) Colloides Naturels Inc., Bridgewater, NJ, USA.

Acacia gum is an all-natural, GMO free, highly functional source of soluble dietary fiber. It is widely used in bakery and cereal based products for its unique technological properties. In recent studies done by The Food Development Group in Toronto, the benefits brought by acacia gum are clearly shown in two sweet baked goods: A chewier and softer texture is observed in muffins during the entire shelf life period when 1% acacia gum is added. The texture of cookies becomes chewier and less crumbly at increased acacia gum levels from 0 to 3% of the total formula. Cookies with 3% acacia gum in the total formula are rated highest, showing superior eating qualities over the control cookie during the entire shelf life. Acacia gum also brings proven nutritional and health benefits to bakery and cereal based products: fiber enrichment and prebiotic effect to improve digestive health and improve regularity. Recent studies proved that addition of acacia gum into different types of bread had a significantly impact on the glycemic index.

O-70
Measurement of mechanical properties of co-extruded dual phase products. L. Samuel (1), H. DOGAN (1), J. L. Kokini (1). (1) Rutgers University, New Brunswick, NJ, USA.

Coextrusion has introduced a wide variety of dual phase products (pockets) in snack food, breakfast cereal and pet food sector. Inherent differences in the physical states and compositions of the two phases offer different textural attributes. The main focus in textural characterization of such products is to differentiate between the mechanical properties of each phase (shell and filler). We identified test method and conditions that can objectively differentiate between the textures of phases in dual phase products. Penetration tests with punch probe gave the most reliable, reproducible and comprehensive mechanical characterization. A robust and operator independent macro was developed to derive quantitative measures for the textural properties of the shell and the filler, such as hardness, toughness and elasticity. The differences in the mechanical properties of the shell and filler were used to deconvolute the textural differences between these two phases. In order to evaluate the effectiveness of the test in deconvoluting the textural properties, penetration tests were done on the shell and filler layers individually as well as the whole pockets. The mechanical properties derived for the upper shell by the proposed method corresponded well to those of the individual shell layer. For the filler and lower shell, however, the force readings for the whole pocket were higher than those for the corresponding individual layers, which was due to the continuous resistance offered by the preceding layer(s) as the probe penetrates through the layers. After subtracting the residual forces, the mean force readings for whole pockets showed comparable values with those of the individual phases. Validations on a variety of commercial products have shown that the developed method can accurately differentiate not only between the phases but also among the samples.

O-80
Psychophysical markers for crispness and influence of phase behavior and structure. H. DOGAN (1), J. L. Kokini (1). (1) Rutgers University.

Crispness is the most significant and commercially important texture descriptor for cellular foods. In this study we aimed to understand the physical basis of crispness, through elucidation of the role of structure and phase behavior of the food polymer matrix. Corn extrudates were used as model solid food foams. Extrudates of a wide range of cellular characteristics were produced by varying the extrusion parameters in the ranges of 120–200°C barrel temperature; 15–25% feed moisture content, and 200 rpm screw speed using a single screw laboratory extruder (Brabender Instruments Inc.). Cross-sectional images of extrudates were analyzed using image analysis techniques to measure average cell size and cell size distribution, cell density, cell wall thickness and cell wall thickness-to cell radius ratio (t/R). Bulk and solid densities of extrudates were measured using volumetric displacement techniques. Differential scanning calorimetry was used to determine glass transition temperatures (Tg). Uniaxial compression was used for textural characterization. Jaggedness of the resulting force deformation curves was quantified using three techniques: Fractal analysis, ratio of linear distances and the average number of peaks (Np). Accurate mechanical methods were developed to count the peaks and relate them to sensory crispness. Np was found to be a good predictor for sensory crispness scores generated using psychophysical models (R(^2) = 0.71). Constitutive models were developed to relate phase behavior and structure of cellular foods to Np. The effect of cellularity and phase behavior on Np was investigated by non-linear regression between Np and t/R and Aw. Np decreased exponentially both with an increase in t/R and water activity level (R(^2) = 0.95). This parameter further varied systematically with phase change in extrudates characterized with the use of T-Tg.

O-82
Acoustic emission, fracture behaviour and morphology of dry cellular crispy foods. T. VAN VLIET (1), H. Luyten (1), W. Lichtendonk (1). (1) Wageningen Centre for Food Sciences, Wageningen, The Netherlands.

For many food products their crispy character is an important sensory characteristic. It is generally accepted that it is related to the fracture behaviour of the food. It requires multiple brittle fractures accompanied by acoustic emission and relatively low work of mastication. These demands set clear requirements to a product both at molecular and mesoscopic scale. The main process acting at molecular scale is the required brittle fracture accompanied by acoustic emission. This means crack growth speeds of about 300 – 400 m s(^–1). This high speed in combination with the need for multiple fracture events and a low work of mastication sets clear requirements on the morphology of the product regarding optimum beam and pore sizes. Fracture behaviour and sound emission of toasted rusk rolls and biscuits were measured at a data sampling rate of 65000 data points per second, allowing registering the fracture of individual beams or lamellae forming the cellular structure of the crispy food. From measured properties like the occurrence of sound, the sound energy, the duration of single sound events, the minimum time interval between sound events to be heard as separate events by humans and from the required size of the force drops on fracture of a beam or lamellae it was possible to calculate morphological constraints for the cellular structure of the crispy foods. During the presentation we will present data for the minimum and maximum sizes of the pores and of the sizes of the solid material elements surrounding them for a typical dry crispy product. These sizes were found to be of the order of 50–500 micrometer.

O-103
Breeding wheat for cookies: Solvent retention capacity, wire cut, and sugar snap cookies. M. J. GUTTIERI (2), E. J. Souza (1), K. M. O’Brien (2), M. Kweon (1). (1) USDA-ARS, Wooster, OH; (2) University of Idaho, Aberdeen, ID.

Soft wheat quality in plant breeding traditionally is measured by the AACC sugar-snap cookie method (AACC 10-52), which was developed as a qualitative measure of damaged starch due to milling, particularly to eliminate cultivars with hard grain. Most current soft wheat breeding programs use rapid methods (e.g. NIR or SKCS) to eliminate hard wheat segregants, but continue to use the sugar snap cookie test as a measure of quality. Using 21 soft white spring wheats grown in 2004 and 2005 at three Idaho locations, we compared the sugar snap cookie method with newer measures of soft wheat quality with measured solvent retention capacity (AACC 56-11), wire-cut cookie quality (AACC 10-54), and TA-XT2 analysis of wire cut cookies. Using the F-test to estimate the power of these quality measures to detect genetic differences, we found genetic differences for all the quality parameters measured, except wire-cut cookie moisture loss and stack height; these two traits were the least sensitive traits for differentiating among genotypes. We found the greatest variation among genotypes, based on the F-test, for the four solvent retention capacity solvents (water, sodium carbonate, sucrose, lactic acid) and the TA-XT2 texture analysis. The cookie diameter, whether wire cut or sugar snap, had intermediate power to differentiate genotypes with F-values of 2.2 to 2.9 (P < 0.001). Of the baking test parameters the TA-XT2 snapping force had the greatest differentiation, with an F-test value of 4.2 (P < 0.0001). Plant breeders may be able to achieve greater gain from selection if they choose to use other measures of end-use quality besides the sugar snap cookie test. These alternatives to sugar snap cookie include the less expensive solvent retention capacity test and the some what more labor intensive texture analysis of wire cut cookies.

O-104
Citrus fiber ingredients for adding strength to cracker products and moistness to baked products, including whole grain breads. B. LUNDBERG (1). (1) Fiberstar, Inc., Ellsworth, WI USA.

A correlation was found between increasing amounts of Citri-Fi® 100FG and an increase in cracker strength as measured by a texture analyzer. A 24.8% increase in cracker strength was found when Citri-Fi® 100FG was added at 1% compared to a control. This increase in strength significantly reduces potential for breakage and costly amounts of damaged product. Another trend noticed during the testing of the crackers was the numbers of stress fractures were reduced with the presence of Citri-Fi® 100 FG. In terms of adding moistness to baked products, a 17% increase in softness was found when Citri Fi® 300 FG was added at 1% along with additional water at 4.5 times the fiber weight and additional oil at two times the fiber weight compared to a control in a biscuit. Additional testing in other baked products has verified these results over a broad range of baked whole grain applications. The ultra-high water binding and surface area capacity of Citri-Fi® ingredients are the unique features that enable it to function at increasing strength in dry cracker product and adding moistness to baked products. Citri-Fi® ingredients have a water holding capacity over 8 grams water per gram fiber as measured by AACC 56-30 and contains approximately 33% soluble fiber and 37% insoluble fiber. Citri-Fi® ingredients are all-natural products that do not have negative effects on the volume, taste, or texture.

P-126
Characterization of dough texture and adhesiveness in Mexican traditional bread named “Conchas” fortified with heat precipitated whey proteins. E. Diaz-Maldonado (2), S. Soto-Simental (2), M. Reyes-Santamaría (2), J. Franco (2), A. Totosaus-Sanchez (1), N. GUEMES-VERA (2). (1) Instituto Tecnologico de Estudios Superiores de Ecatepec; (2) Instituto de Ciencias Agropecuarias-UAEH, Tulancingo, Hidalgo, Mexico.

Mexico has serious nutritional problems, due low income of the population. In spite of that Mexican people consuming a variety of traditional breads, but there are disposal of animal protein like whey proteins considered an environmental problem. Thus, this research will be contribute diminish that nutritional problems. There is not information about the effects of whey heat-precipitated in dough of this kind of traditional bread. The aim of the present work was to characterize the dough texture and adhesiveness of sweet bread named “conchas” fortified with heat-precipitated whey proteins. A proximal analysis was developed. After that dough was prepared with wheat flour (WF) fortified with various levels of whey proteins (10, 15, 20, 25 and 30%). Later the rheological analyses (TPA and adhesiveness) were performed by using a TA.XT2i texture analyzer (Stable MicroSystems Ltd., Surrey, UK) in a compression mode. The chemical composition of the flour was 9.0% protein for WF and 20% protein for whey heat-precipitated. The bakery product fortified with 15% of precipitate had 23% protein as compared to 17% in the regular product, which agreed with other results reported in the literature. The addition of 10% whey protein precipitate produced a decrease in the firmness and consistency, and an increase in the cohesiveness of the dough. Generally speaking, higher amounts of precipitate (30%) did not significantly affect the firmness, consistency or cohesiveness of the dough. The adhesiveness increased particularly in samples prepared with 25 and 30% of whey protein precipitate. The presence of whey proteins produced a decrease in the firmness and consistency of the dough and an increase in its cohesiveness, which favours the production of a high-quality product.

P-137
Evaluation of corn masa stickiness. R. YGLESIAS (1), D. S. Jackson (1). (1) Department of Food Science & Technology, University of Nebraska, Lincoln, NE, USA.

Stickiness is a physical attribute greatly impacted by masa moisture content, starch degree of cook and protein alterations. To better understand stickiness in corn masa, white corn (1851W, 2000 crop year) was cooked at 100°C for 20, 30 and 40 minutes using a laboratory nixtamalization method, and ground using a small scale stone grinder. Stickiness was measured over time for 2 hours using a TA-XT2i texture analyzer in Adhesiveness Test mode. Masa moisture contents and temperatures were also determined over time. Temperatures of ground masa significantly (P < 0.05) increased as the time of cooking increased. Stickiness of masa cooked for 20 minutes was significantly lower (P < 0.05) than stickiness of masa cooked for 30 or 40 minutes. Changes in masa stickiness significantly (P < 0.05) decreased over time for masa samples cooked for 20 minutes and maintained steady for masa samples cooked for 30 or 40 minutes. Masa stickiness for undercooked corn (20 minutes cooking time) significantly decreased with moisture loss, where for cooked and overcooked corn (30 and 40 minutes cooking time) moisture loss was not the primary variable influencing stickiness properties. This suggests that masa stickiness is a phenomena caused by multiple factors.

P-147
The use of selected lactic acid bacteria to improve the baking and rheological quality of gluten-free batter and bread. L. A. Ryan (1), F. Dal Bello (1), S. RENZETTI (1), E. K. Arendt (1). (1) Food Technology, Food and Nutritional Sciences Department, UCC, Cork, Ireland.

In recent years the demand for gluten-free (GF) cereal products has increased, due to the fact that it is estimated that 1 in 100 people worldwide is suffering from celiac disease. The only treatment for this condition involves a GF diet that avoids ingestion of gluten-containing cereals and their products. GF products are generally considered of poor quality, especially when compared to their gluten-containing counterparts. The aim of this study was to improve the quality of GF bread by addition of sourdough. GF sourdough (dough yield of 200) was fermented for 24 hrs at 30°C using selected lactic acid bacteria (LAB) isolated from cereal environments. The sourdough was added at 20% of the total flour and the GF bread was baked. A variety of tests including volume, colour, moisture, digital image analysis as well as texture profile analysis were performed. Rheological tests were carried out to determine structure development during sourdough fermentation as well as after the addition of sourdough to the bread batter. The rheological tests included oscillation at varying frequencies, viscometry as well as creep analysis. The rheological development of the sourdough during fermentation was performed using a single frequency oscillation test over 12 hrs. Results indicate that addition of LAB in the form of sourdough to a GF bread recipe has a positive effect on the baking quality, particularly regarding the volume and texture. Interestingly, the rheological properties of the GF sourdough were found to be different from common wheat and rye sourdoughs, with an increase in elastic modulus being observed over the initial fermentation period. In conclusion, results collected so far indicate that the addition of sourdough fermented by selected LAB strains can positively influence the baking and rheological properties of GF bread and dough.

P-152
Changes in physical and sensorial properties of cheese breads with or without the addition of pre-gelatinized cassava starch. J. R. Uclés-Santos (1), F. P. COLLARES (1). (1) State University of Campinas - UNICAMP, Department of Food Technology, Campinas, SP, Brazil.

Cheese bread is a product that can incorporate functional ingredients without altering its physical and sensorial properties. The aim of this work was to study the effects of adding sour cassava starch (0 to 100%), soy proteic isolate (0 to 10.54%) and polydextrose ((0 to 5.07%) to cheese breads, using a surface response method with three variables and five levels (-alpha, –1, 0, +1, +alpha), applied twice (with or without scalding), in their physical and sensorial properties. Initially, the functional ingredients and the pre-gelatinized cassava starch were characterized physico-chemically and morphologically. The particle size distribution of soy proteic isolate and pre-gelatinized cassava starch presented diameters of 86.72 µm and 42.53 µm, respectively, meanwhile, polydextrose didn’t attain satisfactory results due to the presence of a wide range of particle sizes. The results obtained trough the experimental designs, did not present significant difference (P < 0.05) for texture, luminescence and saturation of crust and crumb, concluding that the use of any concentration studied for each variable, does not interfere in a significant way with these properties with or without pre-gelatinized cassava starch. The cheese breads elaborated with the addition of pre-gelatinized cassava starch presented a mathematical model, explaining the behavior of the variables studied in relation to the cheese bread volume, noting that the ranges of concentration obtained through the response surfaces showed that it is possible to obtain volumes as high as 4.286 cm(^3)/g and 5.03 cm(^3)/g. For sensorial analysis six different formulations of cheese breads were evaluated by 30 panelists, who did not detect significant difference (P < 0.05) in terms of overall appearance, aroma, color of the crumb and flavor.

P-157
Formulating bread fortified with soluble and insoluble fiber. M. B. NIETO (1). (1) TIC Gums, Inc., Belcamp, MD, USA, in collaboration with Nealanders International, Inc.

Fiber bread containing insoluble fiber as high as 20% flour basis has been successfully developed and commercialized for many years now. However, recipes that contain the same amount of soluble fiber proved to be a challenge. In this work, gums were studied for their gluten compatibility, and to achieve the target usage level of 20%, they were carefully selected based on viscosity and water absorption. A gum system that could be used at the same level of 20% flour basis was developed for a total of 40% combined soluble and insoluble fiber. Gums, as the main source of soluble fiber, are complex polysaccharides that are either branched or linear, and neutral or charged. This structural feature and the electrostatic charge on the molecule have a profound effect on the gluten in the formation of disulfide bonds and the elasticity of the dough. Neutral and linear gums proved to be compatible with the gluten. Therefore, a gum system consisting of inulin, guar and methylcellulose was developed. This gum system has the same water absorption as the flour when supplemented with vital wheat gluten. High fiber breads using this gum system combined with the insoluble fiber such as cellulose powder produced loaves with good volume and bread structure, and the breads were soft and had a moist mouthfeel.

P-162
Natural and sour cassava starch content in cheese breads: Effect on physico-chemical, rheological and sensorial properties. J. R. Uclés-Santos (1), F. P. COLLARES (1). (1) State University of Campinas - UNICAMP, Department of Food Technology, Campinas, SP, Brazil.

Cheese bread is considered a baked product that does not contain gluten, because it uses native cassava starch, naturally fermented and/or modified in its elaboration. The present work analyzed the incorporation of different contents of natural and sour cassava starch (0%, 30%, 50%, 70% e 100%) to the cheese bread dough, with the objective of choosing a formulation for cheese bread with optimized expansion coefficient, low compression force and good sensorial acceptance. Prior to the formulation choice, the cassava starches were characterized physically, chemically, rheologically and morphologically. The values of pH, acidity and moisture were within the parameters established by Brazilian legislation for amylaceous products. The particle size was 21.76 µm for natural cassava starch and of 3 to 20 µm for sour cassava starch. The B pattern of X-ray diffraction found was characteristic for tuber starches. The natural and sour cassava starches presented paste temperatures of 66 and 67°C, respectively. The specific volume of cheese breads ranged from 3.23 to 4.19 cm(^3)/g. The compression force obtained for the cheese bread ranged from 15.29 to 23.59 N. The cheese breads elaborated only with natural or sour cassava starch presented greater values of luminescence, saturation and shade angle, parameters obtained through the analysis of color. The affective sensory analysis performed with 30 untrained panelists, showed that the cheese breads elaborated with high contents of natural cassava starch presented the best sensorial scores as to overall appearance, aroma, texture and flavor, if compared to the ones elaborated with high contents of sour cassava starch. The formulation of cheese bread with 70% of manioc starch and 30% of sour starch was chosen as the best formulation.

P-163
Particle size effects of whole barley flour on the quality of wheat tortillas. N. PRASOPSUNWATTANA (1), A. Toma (1), S. Lee (1), S. Chongcham (1), P. Cooke (3), R. A. Flores (4), J. Wilson (3), E. A. Arndt (2), W. Yokoyama (5), M. Omary (1). (1) California State Polytechnic University, Pomona, CA, USA; (2) ConAgra Foods, Inc., Omaha, NE, USA; (3) Microscopic Imaging Group USDA/ARS/ERRC, Wyndmoor, PA, USA; (4) University of Nebraska, Lincoln, NE, USA; (5) USDA, ARS, Western Regional Research Center, Albany, CA, USA.

Low-fat high-fiber wheat tortillas enriched with 9% whole barley flour (WBF) rich in total dietary fiber and beta-glucan soluble fiber were prepared. Four treatments including a control-C (72µ), and WBF with three different particle sizes, microground-MG (68µ), intermediate-I (131µ), and regular-R (237µ) were evaluated. Ninety-five untrained panelists tested the tortillas for appearance, color, flavor, texture and overall acceptability using a 9-point hedonic scale. Data on water activity, color, texture, and SEM imaging of dough and tortillas were also collected. Two commercial products (CP) were also included for comparison. The MG and R tortillas were not significantly different (P > 0.05) from C on flavor (5.8) and texture (5.7) scores, respectively; but were rated significantly lower (P < 0.05) than both CP on the same attributes. Water activity was significantly different between C (0.972) and R (0.981). No significant differences in water activity were found among MG, I and R (0.98). Tortillas made with MG, I, and R were significantly darker (61) than the two CP. The firmness was significantly higher for MG, I, and R (0.76 kg) than both CP (0.44 kg). No significant differences were found in toughness for one of the CP, C and R (2.4 kg.s); however, I and MG tortillas were significantly less tough (1.96 kg.s). Elasticity among the experimental tortillas (0.16 kg/mm) was not significantly different. The two CP were significantly less elastic (0.078 kg/mm) than all experimental products. Similar amounts of beta-glucan were found among all WBF tortilla doughs. The microstructure of protein matrices and starch granules in the tortillas was more compact and uniform than corresponding doughs.

P-164
Physicochemical, rheological and sensorial characterization of functional cheese bread with addition of soy protein isolate and polydextrose. J. R. Uclés-Santos (1), F. P. COLLARES (1). (1) State University of Campinas - UNICAMP, Department of Food Technology, Campinas, SP, Brazil.

In Brazil, cheese bread is a widely consumed food with no functional component. The objective of this work is to compare two formulations of functional cheese bread with regard to their physicochemical, rheological and sensorial properties. The two formulations assessed here have been previously obtained as the result of two independent experimental selection processes; one of them involved the scalding of the powdered ingredients. The two formulations selected were: (i) FCE (with scalding): 35% of native cassava starch, 5.50% of soy protein isolate and 6.04% of polydextrose; (ii) FSE (without scalding): 7.00% of pre-gelatinized cassava starch; 35% of sour cassava starch, 5.50% of soy protein isolate and 1.03% of polydextrose. The others ingredients added to these formulations were: whole milk, soy oil, margarine, salt, whole eggs and half-cured ‘Minas’ cheese. The study of dough consistency by Brabender farinograph showed that the dough elaborated from FCE formulation presented a consistency of 40.66% superior to the ones obtained for dough elaborated from FSE formulation. The FCE formulation presented specific volume and coefficient of expansion, respectively, 1.84% and 50.0% smaller than the ones obtained by the FSE formulation, which was also confirmed through the analysis of compression force. The centesimal composition determined for the FCE and FSE formulations, presented a content of lipids of 31% and 28%, protein around 8%, fixed mineral residue between 1% and 3% and total carbohydrates (in dry basis) from 58 to 60%, respectively. The sensory analysis for preference, by paired comparison, showed that the consumer presented the same acceptance (50%), from the already 30 panelists used. These results showed that despite the fact that the products have different physicochemical and rheological properties, they are equally accepted by sensorial analysis.

P-170
Assessment of the suitability of a range of gluten-free cereals for their potential use in gluten-free bread. M. M. Moore (1), S. RENZETTI (1), E. K. Arendt (1). (1) Food Technology, Food and Nutritional Sciences Department, UCC, Cork, Ireland.

The suitability of white rice, brown rice, corn, tef, buckwheat, sorghum and oats for their potential use as ingredients for a gluten-free bread was assessed. Rheological tests on the bread batters and standard-baking tests on the resulting breads were carried out. Significantly higher elastic and complex modulus values were found for the OF, S and BW GF bread batters (P < 0.05). These bread batters exhibited more elastic properties similar to that of wheat dough than their counterparts. Furthermore significantly higher complex viscosity values were found for the OF and S GF breads, which rapidly decreased overtime (P < 0.05). Baking tests revealed the BRF, TF and BW breads to yield the highest loaf volumes (P < 0.05), lower bake loss and crumb hardness values (P < 0.05). Significantly lower crust colour values were found for the OF, BRF, TF and BW breads indicating that these breads were darker in colour (P < 0.05). The hardness of all breads significantly increased over storage time (P < 0.05), although the increase from day 2 to day 5 was no longer significant for OF and BW. Regarding the BW and OF GF breads, although high crumb hardness values were obtained, the rate of staling was less pronounced when compared to the WRF, TF, CF and S GF breads. Fracture occurred only for most of the GF breads (BRF, TF, CF, S and BW) at day 2 and 5 with the exception of GF bread. Overall it can be concluded that OF, BRF and BW were the most suitable GF cereals for potential use in GF bread production.

P-173
Comparing the effect of mixing on dough development between two mixers with different geometries. R. K. CONNELLY (1), R. McIntier (1). (1) University of Wisconsin – Madison, WI, USA.

The farinograph and reomixer (mixograph-type mixer) are two common devices for assessing flour properties during mixing. Both mixers provide empirical measurements related to the torque and work input required to produce optimally mixed dough, despite dissimilar geometries and mixing actions. The overall objective of this work is to obtain a more complete understanding of the effect of the rate, type and range of strain experienced by dough as it is mixed to peak development over a range of strain rates. Initial testing focused on mixing flour-water dough to peak development at varying speeds. Work input to reach peak torque was determined and used to compare the two mixers. Results confirm the dependence of the work needed to fully develop dough on mixing speed at low speeds and its independence at high speeds. The speed at which dough development becomes rate independent is different for each mixer and serves as a comparison point. Subsequent testing focused on full formula bread dough mixed to peak development at varying speeds. Differences in the fully developed dough were sought by measuring small strain rheological properties of the dough following thermal yeast inactivation, extensional properties using the Keiffer rig on the texture analyzer and near-infrared spectra. Dough was also baked and assessed for loaf volume, color and texture. Results of tests conducted on full formula dough from each mixer were compiled separately and analyzed using a multivariate ANOVA, and additional points of comparison between the two mixers were identified. Ultimately, the work unites information gained on both the farinograph and the reomixer and conveys them into a unified theory leading to more reliable mixer characterization methods.

P-179
Effect of mixing time and water absorption on the quality of Chinese steamed bread. E. ASSEFAW (1), B. X. Fu (1). (1) Canadian International Grains Institute.

Early research in our laboratory has shown that mixing time and water absorption are key processing parameters affecting steamed bread quality. Detailed understanding of their impacts is critical for establishing laboratory steamed bread processing and quality evaluation procedures which can objectively demonstrate the quality of flour or wheat for steamed bread processing. To this end, steamed breads were processed under varying levels of mixing time and water absorption from flour milled from Canada Western Hard White Spring (CWHWS) wheat. The resulting steamed breads were evaluated in terms of volume, color, exterior appearance, and crumb structure and texture. There are minimum levels of water absorption and mixing time below which the dough would be too stiff for steamed bread processing. The results showed that the overall steamed bread quality improved with the increase of mixing time, and bread quality deteriorated significantly beyond certain water absorption level. It was found that long mixing time and low water absorption usually produce good quality steamed breads as long as the dough consistency can meet the processing requirements.

P-186
Influence of harvest year, sowing date, and irrigation management on protein composition, rheological properties and baking performance of wheat lines. A. R. ISLAS-RUBIO (1), T. L. Maldonado-Parra (1), M. A. Camacho-Casas (2), M. Granados-Nevárez (1), B. Siva-Espinoza (1), F. Vásquez-Lara (1), H. González-Ríos (1). (1) CIAD, A.C., Hermosillo, Sonora, México; (2) CIRNO-INIFAP, Ciudad Obregón, Sonora, México.

Wheat quality is determined by genetic and environmental factors. The type of soil, climate, time and year of harvest and management practice are some of the environmental factors that influence the quality of wheat. The aim of this work was to evaluate the effect of year of harvest (YH), sowing date (SD), and irrigation management (IM) on protein composition, rheological measurements, and baking performance of three experimental bread wheat lines (EBWL) grown at the Yaqui Valley Experimental Station in Sonora, México, during two consecutive years. Polymeric and monomeric proteins were evaluated by SE-HPLC. Dough rheological measurements were conducted using the National mixograph and a texture analyzer TA-XT2 with the Kieffer extensibility rig. Baking performance was evaluated by the direct dough method. The main factors and some of their double interactions had a significant effect on protein composition. Most of the rheological measurements were significantly influenced by EBWL, YH, SD, interactions YH and EBWL, YH and SD, YH and IM, EBWL and IM. IM had no significant effect on baking performance, but its interaction with YH had. In general, flours from EBWL-3 had significant lower proportions of polymeric and non-extractable protein, and lower bread volume than flours from the other EBWL.

P-189
Production and optimisation of bread from wheat and amaranth flour blends. R. SCHOENLECHNER (2), C. Scelsi (1), M. Mariotti (1), M. Lucisano (1), E. Berghofer (2). (1) Department of Food Science and Microbiology, University of Milan, Milan, Italy; (2) Department of Food Science and Technology, University of Natural Resources and Applied Life Sciences, Vienna, Austria.

Amaranth, a grain which can be used similarly to cereals, is a nutritionally rich plant. As it is not botanically a true cereal, its chemical composition is quite different, especially as regards protein quality: amaranth, in fact, does not contain gluten, which is responsible for the network development and the gas holding capacity of a dough. As reported in literature, blends of wheat (70–80%) and amaranth (20–30%) flour showed decreased dough mixing time, mixing tolerance, stability, gelatinization temperatures, viscosities and increased water binding capacity. Breads showed lower loaf volumes, higher moisture retention and longer shelf life. In this study, blends enriched with high amounts (40%) of amaranth wholemeal flour were used in the bread making process. To increase the quality of the final products, the effect of different additives was evaluated by applying statistical experimental designs. In particular, the addition of emulsifiers, guar gum and gluten as well as water were investigated. All breads were evaluated for their textural properties, as crumb firmness and relative elasticity (texture analyser), porosity (image analysis), volume (rapeseed replacement) and crust colour (Dr. Lange Microcolor). The highest influence on improving bread quality was related to the increase of water in the dough, which had a strong interaction with the emulsifiers. Guar gum had good effects when added in low amounts, while gluten addition caused contradictory results and its use at the present stage is questionable. Sensorial evaluation of the optimised breads proved that their textural properties were within the range of breads available on the market.

P-190
Production and utilization of a fluid monoglyceride hydrate emulsifier in a high speed bakery operation. B. R. SEBREE (1). (1) Archer Daniels Midland.

It has long been known that a hydrate form of a fully saturated monoglyceride provides for improved functionality (starch complexing) in a bakery system. This is due to the pre-hydration of the product making it instantly functional in the bakery system. However, current monoglyceride hydrates are available only in a difficult to use paste/shortening form. A process was developed to produce such a product in a fluid/pumpable form that could be more easily utilized in a bakery operation. Microscopic and analytical testing shows the product to be a mixture of alpha-gel and beta-crystalline material very similar to that of the currently used paste/shortening monoglyceride hydrates. The liquid-hydrate product was tested at AIB in a no-time dough system against a powdered-fully saturated distilled monoglyceride, a 22 IV self-hydrating distilled monoglyceride and a standard monoglyceride hydrate (along with a control containing no monoglyceride addition) at equal total monoglyceride inclusion. Bread made from the liquid-hydrate and standard-hydrate emulsifiers scored highest on texture/mouthfeel characteristics and had the highest specific volumes. The 2 hydrate products outperformed the dry-addition monoglycerides for staling properties (firmness at 7 days) and were not significantly different from each other.

P-192
Stickiness of wheat flour doughs and relationship to breadmaking performance and other physical dough tests. F. WANG (1), Y. Zhang (1), W. Zhang (1), W. Chen (1), P. Zhang (1). (1) Henan University of Technology, Zhengzhou, Henan, China.

Measurements of stickiness of wheat flour doughs were made using a TX-XT2 texture analyzer with a dough stickiness cell-probe. A series of wheat flours with various breadmaking potentials were tested at farinograph water absorption and optimum mixing. The flour-water doughs of Chinese wheats exhibited stickier behavior. The stickiness of doughs was highly negatively correlated (r = –0.83) to bread loaf volume for Chinese wheats. Lower dough stickiness favored larger loaf volume of bread. However, there was no correlation (r = –0.13) between dough stickiness and Chinese steamed bread volume. The stickiness of flour-water doughs also was highly correlated to some of the physical dough parameters provided by mixograph, farinograph, and extensograph.

P-193
Technological and sensory evaluation of pan bread elaborated with mixes of wheat flour and unripe banana flour or commercial resistant starch. R. Ormenese (1), C. Batista (2), M. Cáceres (2), Y. K. Chang (2), C. J. STEEL (2). (1) ITAL, Campinas, SP, Brazil; (2) UNICAMP, Campinas, SP, Brazil.

Resistant starch (RS), that resists digestion in the small intestine and is fermented in the large intestine, has effects similar to dietary fiber and is considered a functional ingredient. In this work, the effect of two different sources of RS, unripe banana flour (UBF) or commercial resistant starch (CRS), on technological and sensory properties of pan bread were studied. Wheat flour was substituted by three different levels (10, 15 and 20%) of UBF or CRS. A control bread was prepared with 100% wheat flour. UBF and CRS presented 9% and 60% RS, respectively. Specific volume, moisture content, water activity and texture (firmness) of breads from all formulations were determined. Results were analyzed by ANOVA and the Tukey test. Volume decreased significantly with an increase in the percentage of UBF or CRS, with UBF having a greater effect. The highest value was 4.91 mL/g (control) and the lowest value was 2.92 mL/g (bread with 20% UBF). Only the bread with 20% UBF had a higher moisture content than the rest (35.63%, compared to the control with 32.66%). Water activity was the same for the control (0.968) and for the breads with CRS (average of 0.958), and lower for the breads containing UBF (average of 0.942). With respect to firmness, breads with CRS presented values that ranged from 263.33 to 325.31 gf, breads with UBF ranged from 215.10 to 338.17 gf and the control was 218.53 gf. The sensory acceptance test carried out with 35 untrained panelists showed that the breads with 10% UBF or 10% CRS were satisfactory. The levels of RS (dry basis) of these breads (10.21% RS for the bread with 10% UBF and 13.16% RS for the bread with 10% CRS) showed significant increases with respect to the control (8.45% RS). Thus, it is possible to substitute 10% of the wheat flour in bread by up to 10% UBF or CRS to produce pan bread with greater health benefits.

P-203
Understanding the basis of flour tortilla stickiness. J. H. Rathod (1), H. Dogan (1), J. L. KOKINI (1). (1) Rutgers University.

Tortilla stickiness is highly undesirable for the food service industry. In this study it was aimed to understand the factors which control stickiness in wheat flour tortilla products based on a phase/state-change approach and measurement of surface properties. A variety of commercial wheat tortillas with a wide range of stickiness scores as indicated by sensory panels were selected. Tortilla samples were equilibrated to different water activity (A(w)) levels in the range 0.12–0.97 to characterize the phase/state of the tortilla at controlled relative humidity and temperature. Moisture sorption isotherms were developed. Differential scanning calorimetry (DSC) and mechanical spectroscopy were used to characterize the phase behavior. We used wide-angle X-ray scattering to understand the effect of crystallinity, contact angle measurements to determine the surface hydrophobicity through surface energy calculations. An objective instrumental test technique was developed using a texture analyzer to quantify the stickiness in tortilla samples. Instrumentally observed stickiness was linked to surface chemistry of the tortilla samples by contact angle measurements. Instrumental stickiness scores showed a close agreement (R(^2) = 0.85) with the sensory scores. The developed state diagram has shown that both sticky and non-sticky tortillas have similar phase behavior. Water activity had a significant impact on tortilla stickiness. Polar component of surface energy was found to have a strong correlation with stickiness. Higher product A(w) resulted in increase in surface energy which in turn caused an increase in instrumental stickiness scores (R(^2) = 0.82). Tortillas with high surface energy (driven by high A(w)) are more likely to stick to each other.

P-213
Development of an organic fiber-rich extruded breakfast cereal using passion fruit fiber and corn flour: Evaluation of technological properties. G. Vernaza (1), C. J. STEEL (1). (1) UNICAMP, Campinas, SP, Brazil.

Consumers are more and more aware of the health benefits they can obtain from their food and the demand for both functional and organic foods is increasing. Among functional foods, those enriched with fibers have had a positive acceptance. The aim of this study was to evaluate the effect of thermoplastic extrusion and the addition of an alternative fiber source (organic passion fruit fiber) on technological properties of an organic fiber-rich extruded breakfast cereal. A 23 central composite rotational design (CCRD) was used, permitting the analysis of the results by the response surface methodology. The effects of raw material moisture content (18–28%), added fiber (0–30%) and second and third zone barrel temperatures (120–160°C) on the expansion index (EI), instrumental hardness and color (CIELCh system) were studied. The EI ranged from 1.02 to 4.11. Maximum EI is desirable. The response surfaces demonstrated that at lower moisture content, fiber and temperature, higher expansion was obtained. Hardness varied from 9.36 to 25.73 N. Minimum hardness is desirable. The response surfaces showed that at lower moisture content and fiber; at lower fiber and temperature; and at lower moisture content and higher temperature, lower hardness values were obtained. Color is the result of the mix of ingredients and can be an indicator of extruder parameters and the intensity of the Maillard reaction. The response surfaces for chroma (C) indicated that at the lowest values of the three variables studied, the maximum values for this response were obtained. The response surfaces for lightness (L) showed that higher fiber contents yielded darker products; higher temperatures yielded lighter products; and moisture had little effect.

P-215
Properties of extruded products made from high beta-glucan and traditional oat lines. N. YAO (2), J. Jannink (1), S. Alavi (3), P. J. White (2). (1) Department of Agronomy, Iowa State University, Ames, IA, USA; (2) Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA; (3) Department of Grain Science and Industry, Kansas State University, Manhattan, KS, USA.

The impact of extrusion processing on the physical and sensory properties, and on in vitro bile acid (BA) binding of two oat lines, N979 and Jim, with beta-glucan concentrations of 8.1% and 4.8%, respectively, were examined. For optimization purposes, cereal based on the Jim variety was extruded at 16%, 18%, 21%, 25%, 28% and 30% moisture contents, and final zone temperatures of 125, 150, 165 and 180°C. Based on hardness and edibility, moisture contents of 16 to 21%, and temperatures of 165 and 180°C were selected for N979 oat cereal extrusion. Jim-based extruded cereal had a significantly greater (P < 0.05) expansion ratio than that based on N979 at most moisture contents. Water hydration of Jim cereal either was greater than N979 cereal or not different at different conditions. N979 cereal was browner, but not harder, than Jim cereal. Cereal made from N979 and Jim had 5.29–5.99% and 3.38–3.94% beta-glucan, respectively. Changing extrusion temperature and/or moisture content did not affect beta-glucan concentration in the final products. Oat cereal made from the N979 line at 165°C and 16% moisture had greater BA binding than did Jim and Cheerios cereal, and had comparable crunchiness. BA binding of Jim cereal tended to increase, whereas BA of N979 cereal tended to decrease when processing temperature increased from 165 to 180°C. Results suggested that proper processing and preparation techniques can generate high quality products with potential physiological benefit from high beta-glucan oat lines.

P-216
Reduced-calorie flour containing type 3 resistant starch used in model extruded cereal system. L. C. HAYNES (3), M. Kweon (4), L. Slade (1), H. Levine (1), J. Locke (3), V. Arora (3), J. Zimeri (2). (1) Food Polymer Science Consultancy, Morris Plains, NJ, USA; (2) Fresh Start Bakeries, Brea, CA, USA; (3) Kraft Foods, East Hanover, NJ, USA; (4) USDA, ARS, SWQL, Wooster, OH, USA.

A reduced-calorie flour replacer containing type 3 resistant starch, made from a process comprised of a gelatinization, nucleation/propagation, and heat treatment stage for an amylose extender corn starch (aeWx VII), was evaluated in a extruded cereal formula. The densified, recrystallized starch has increased total RS yield, reduced water-holding capacity and increased granular density comparable to wheat flour. The flour replacer contains more than 50% by weight, high-melting RS3, which was used to replace 50% of the flour blend in an extruded cereal formula. Superior cereal extrusion characteristics were the result, such as cereal volume, crispness and toasted brown color, comparable to those achieved with conventional soft wheat flour, in contrast to commercially available RS ingredients used at such a high level. In addition, the high melting point of this RS permitted its use in extruded cereal formulations, without substantial loss of enzyme resistance.

P-246
Functional properties of wheat flours adjusted to a constant protein content by addition of starch and gluten. H. GUJRAL (1), B. Baik (1). (1) Washington State University, Pullman, WA, USA.

Evaluation of protein quality and its significance in processing and product quality is a challenging task due to a large variation in the protein content of wheat flours. We determined the validity of adjusting protein content of wheat flours to a constant value by addition of starch and gluten for the evaluation of protein quality independent of protein content. Wheat flours of varying protein contents were milled from two hard (Lolo and Winsome) and one soft white spring (Nick) wheat cultivars grown in five different locations. Flour protein contents ranged from 12.5 to 18.6% for Lolo, 12.3 to 17.3% for Winsome and 10.7 to 15.7% for Nick. The protein content of the flours was adjusted to 14.1% in Lolo and 16.4% in Winsome for the determination of bread making quality parameters and to 12.5% in Lolo and 10.7% in Nick for the noodle making quality tests by adding starch or gluten. Flours of adjusted protein content from Winsome and Nick exhibited lower standard deviation (2.2 and 1.6 mL) in SDS sedimentation volumes than the original flours (3.2 and 3.0 mL). On the other hand, Lolo and Nick showed increased variation in RVA peak viscosity of flours after the protein content adjustments. The variations in dough sheet thickness and cooking water retention of noodles significantly decreased by adjusting flour protein content. The standard deviation in hardness of noodles decreased from >1.37 N in the original flours to <0.69 N in flours of adjusted protein content. The variations in mixograph water absorption; mixing time and loaf volume of bread were also much smaller in flours of adjusted protein content compared to the original flours.

P-248
Hard white wheat: Effect of environment on seed color. O. M. LUKOW (1), K. M. Adams (1), D. Fenn (1). (1) Agriculture and Agri-Food Canada.

Seed color variation of hard white wheat can be a concern in the production of consistent light colored whole wheat food products. To examine the variability of hard white wheat kernel color, commercial samples of the Canadian hard white spring wheat cultivar, Snowbird, were obtained from multiple western Canada locations in 2003 and 2004. Results showed that white wheat seed could range from very white to dark grey-red in color. Snowbird seed samples grown in 2004 appeared visually darker and less vitreous than the 2003-grown samples. In addition to seed color, the 2003-grown samples had higher test weight and protein content, stronger rheological properties and higher whole wheat bread loaf volume compared to the 2004-grown samples. There were more significant correlations of seed color with whole wheat flour color and end-product (bread, tortilla) color in 2003 than in 2004. In overall assessment, the 2004-grown Snowbird samples produced darker reddish colored whole wheat tortillas and pan bread crumb compared to the 2003-grown samples. In both years, there were negative relationships between seed L* and b* values with seed protein content, farinograph water absorption and mixograph strength properties. Positive relationships occurred between seed L* values and particle size index and between seed a* and b* values and test weight.

P-284
Characterization of native manioc starch composite films and their application as coating in pakan pears preservation. F. M. FAKHOURI (1), F. P. Collares (1). (1) State University of Campinas-UNICAMP, Department of Food Technology, Campinas, SP, Brazil.

Edible films and coatings have been increasingly used as alternatives to traditional packaging. The objective of this study was developing and characterizing gelatin and native manioc starch composite films with respect to their physical, barrier and mechanical properties. The filmogenic solutions were prepared separately: (i) 10 g gelatin in 100 mL of water and 5% sorbitol (in relation to the solids content) and (ii) 3 g of manioc starch in 100 mL of distilled water, 10% plasticizer; by heating at 85°C for 10 and 15 minutes, respectively, being then mixed in the proportion 4:1, 1:1, 1:4. One manioc starch simple coating and three composite coatings containing 3% manioc starch and gelatin were then applied on Pakan pears in natura, in the different proportions studied. The pears were covered using the immersion technique and stored alongside the control lot without coating for 28 days at 10°C and 42% UR, to evaluate weight loss. The increase in gelatin concentration caused an increase in the biofilms thickness and permeability to water vapor. Greater variations for the film containing 3% manioc starch was observed, where thickness increased 88% and permeability to water increased from 3.91 to 7.08 gmm/m(^2)dkPa. Furthermore, the increase in protein quantity also caused elevation in resistance to traction, and in solubility in water of composite films. No significant difference was observed in relation to the increase in starch concentration of biofilms which led to the choice of the lowest concentration of manioc starch for obtaining the coatings. The application of coatings helped reduce the weight loss of pears. Whereas the control sample lost 4.27%, the coated samples lost from 3.02 (composite films) to 3.56% (simple films), demonstrating that the coatings studied were effective in extending the shelf-life of pears in natura, stored under refrigeration.

P-288
Evaluation of legume cooking characteristics using a rapid screening method. H. YEUNG (2), R. W. Waniska (2), J. Ehlers (1). (1) Botany and Plant Sciences, University of California at Riverside, CA, USA; (2) Cereal Quality Laboratory, Texas A&M University, College Station, TX, USA.

Continuous growth of improved legume varieties exists to overcome the challenges of new diseases and achieve goals for higher yield. While most legumes are consumed as cooked seeds, consumer preferences for legume products should also be considered and at an earlier stage in the breeding process. Currently used, is the Mattson cooker apparatus, which measures cooking time using weighted plungers. The method, however, requires constant attention and can be difficult for the operator to take accurate notes if several seeds reach the cooked state at the same time. It is important to develop an effective and low-cost method to analyze the cooking quality attributes of new varieties, in order to advance breeding lines. The objective is to use a rapid screening method to evaluate the cooking quality attributes of several cowpea (Vigna unguiculata) varieties grown in the same environment and relate physicochemical characteristics with sensory attributes. Samples of five grams were taken from 24 cowpea varieties and boiled in plastic bags until the majority of the seeds were fully cooked. Broth was drained and the seeds and their broth were separated into dishes. Samples were rated for aroma intensity, the number of split seed coats and cotyledons, turbidity of the broth, cooked doneness, and hardness. Textural properties of cooked samples were determined by Kramer-shear test using the TA.XT2 texture analyzer. Cowpea cultivars grown in the same environment varied in their physicochemical characteristics. This methodology allows observation of distinguishable characteristics between legume varieties. Legumes can then be differentiated into preferred and less preferred categories due to specific requirements of the food processor or consumer.

P-291
Modified manioc fecula edible films and their application in strawberry coating. F. M. FAKHOURI (1), F. P. Collares (1). (1) State University of Campinas-UNICAMP, Department of Food Technology, Campinas, SP, Brazil.

The growing concerns about ecological and environmental conditions have led to the search for alternatives to traditional packaging such as the use of edible films and coatings. In the present study, edible films prepared from modified manioc fecula and gelatin were developed and characterized with regards to thickness, permeability to water vapor, solubility in water, mechanical properties. Afterwards, the filmogenic solutions chosen were applied on strawberries, using the immersion technique and dried at 25°C for 12 hours, with the objective of evaluating their acceptance as to sensorial properties. The solutions were prepared separately: (i) 10 g gelatin in 100 mL of water and 5% sorbitol (in relation to the solids content) and (ii) 3 g and 5 g fecula in 100 mL distilled water and 10% plasticizer; heated at 85°C for 10 and 15 minutes, respectively. These solutions were then mixed in proportions 4:1, 1:1 and 1:4. The films were thicker and with greater values of permeability to water vapor with the increase in of gelatin concentration in the mixture. This addition of gelatin also caused elevation in tensile strength and solubility in water of the films (24.8 – 38.03%). The increase in starch concentration in the biofilms from 3 to 5%, did not significantly influence the value of water vapor permeability, which led to the choice of the filmogenic solutions containing 3% of fecula for the elaboration of the coatings. In the sensory analysis, the coated samples obtained greater acceptance with regards to brightness, global appearance, color and buying intention than the control sample. The degustation showed that the coated samples did not differ from the control sample, which indicates that the coatings did not interfere with aroma, flavor and texture of the strawberries, therefore constituting potential alternatives for the extension of the shelf life of this fruit.

P-293
Composite biofilms manufactured with gluten, gelatin and manioc starch or corn starch (native or modified). L. C. Bertan (2), T. G. Kieckbusch (1), F. P. COLLARES (2). (1) State University of Campinas, School of Chemical Engineering, Campinas, SP, Brazil; (2) State University of Campinas, School of Food Technology, Department of Food Technology, Campinas, SP, Brazil.

Studies involving biofilms stemmed from the need of alternatives to substitute synthetic packaging. The objective of this study was to develop composite films containing starches, gluten and gelatin, at a proportions 1:1:1 and characterize them with respect to permeability to water vapor, solubility in water, tensile strength and elongation. Starch filmogenic solutions were prepared using native or modified waxy corn starch or manioc starches (2 and 4%), water (100 mL) and 10% glycerol (w/w) at 75°C/15 minutes and 85°C/5 minutes, respectively. The gluten filmogenic solution, containing 5 g gluten, 32.5 mL of ethanol in 67.5 mL of water and 20% glycerol and was heated at 75°C/5 minutes The solution was then centrifuged at 5000 rpm/20 minutes and afterwards, 5% glycerol was incorporated. The gelatin filmogenic solution (10 g/100 mL of solution) was prepared at 55°C for 10 minutes, and 5% of glycerol (w/w) was added. The solutions were mixed and the films were made by casting. The permeability to water vapor ranged from 3.22 to 4.48 g.mm/m2d.kPa, differing significantly only between the films composed by 4% native manioc starch and the films composed of 2% modified manioc starch. Solubility in water ranged from 21.54 to 32.35%. An increase in waxy corn starch concentration caused a 25% decrease in resistance to tension. The percentage of elongation ranged from 3.38 to 4.46% and did not present significant differences among all of the films studied. The composite films containing 2% modified manioc starch presented the best water vapor barrier properties and higher resistance to tension. We thank FAPESP for the granting of a doctorate scholarship to student Larissa Canhadas Bertan.

P-294
Cooking time of white corn and its effect on grain hardness and water uptake. A. R. ISLAS-RUBIO (1), L. E. Molina-Jacott (1), B. Silva-Espinoza (1), M. Granados-Nevárez (1), F. Vásquez-Lara (1). (1) CIAD, A.C., Hermosillo, Sonora, México.

The cooking properties of corn are relevant for determining the end-use of this grain. The nixtamalization process involves cooking of corn in water plus lime. During this process, the grain uptakes water to some extent, depending on raw grain hardness and duration of cooking. The aim of this study was to evaluate the effect of cooking time on cooked corn (nixtamal) hardness and water uptake (WU). A white corn grown in Sinaloa, Mexico, during the 2005 cycle was subjected to lime-cooking (1% lime, w/w) in jute bags. After 15, 30, 45, and 60 min of cooking, the nixtamal was removed from the kettle, drained and allowed to cool at room temperature for 10 min. The cooled nixtamal was transferred to polyethylene bags to avoid dehydration while moisture and hardness measurements were taken. Nixtamal hardness (force required to penetrate the grain 2 mm) in three different positions of the grain (ten grains per each cooking time) was determined with the texture analyzer TA-XT2 using a conical probe (45º angle) and a test speed of 0.5 mm/sec. The nixtamal hardness depended on the position where the measurement was taken and was inversely related to cooking time up to 45 min. Hardness of nixtamal cooked for 60 min was not different from that of nixtamal cooked 45 min. Nixtamal water uptake increased with cooking time. A difference of 12% in WU was observed between the nixtamal cooked for 60-min and 15-min. In general, lower hardness values were obtained when measurements were taken from the central upper part of the grain (tip cap down). However, the other two positions (central left side and central right side) provided a more reproducible hardness measurements.

P-302
Extrusion on Goami2 rice – A variety high in indigestible carbohydrates. I. CHOI (3), K. Kim (3), J. Son (3), G. Ryu (2), H. Jeong (1). (1) Department of Food Science & Technology, Chungbuk National University, Cheongju, Republic of Korea; (2) Department of Food Science & Technology, Kongju National University, Kongju, Republic of Korea; (3) Post-Harvest Technology Division, National Institute of Crop Science, RDA, Suwon, Republic of Korea.

Goami2 (G2) developed by mutation breeding via N-methyl-N-nitrosourea treatment to Ilpum (IP), a high quality japonica rice, is high in amylose, fat, protein and indigestible carbohydrate (IDC) contents. The objective was to observe extrusion effects on physico-chemical properties of G2 extrudates. Milled G2 was grounded and extruded in a co-rotating twin-screw extruder equipped with a 20:1 barrel length to diameter ratio. Twelve extrudates were produced at dough moisture (MC:20,25%), screw speed (SS:200,300rpm) and barrel temperature (BT:110,120,130°). Expansion ratio (ER) was calculated by the ratio of extrudate diameter and die diameter (3.0 mm). Bulk density (BD, g/cm(^3)) was measured dividing the mass of extrudate in length (6 cm) by the length multiplied by its diameter. Breaking strength (BS, g) was measured as the resistance of extrudate by a three-point bending test. IDC contents were measured by total dietary fiber analysis (AOAC 991.43). Duncan’s test and response surface methodology (RSM) were used for data analysis. Decreasing MC decreased BD and BS, but increased ER. The lowest BD (0.074) but highest ER (3.410) was found in 20MC, 300SS, 130BT of which BS was also very low (161.015). Considering TDF content (4.8–5.2 g/100 g) in raw G2 rice, some variations were found in IDC depending on extrusion conditions, showing relatively lower IDC (3.85 ± 0.47) with 20MC at 130BT, but higher IDC (6.07 ± 0.75) with 20MC at 110BT. ANOVA also indicated that significant effects of MC, SS and BT on G2 extrudates. From the coefficient magnitude of regression models, MC and BT were the major factors to affect G2 extrudate qualities. Although G2 rice has poor cooking quality for ordinary cooked rice, Goami2 can be processed into value-added products or utilized as ingredients for processed foods.

P-303
Gluten biofilms plasticized with glycerol – Formulation optimization by response surface methodology. L. C. Bertan (2), T. G. Kieckbusch (1), F. P. COLLARES (2). (1) State University of Campinas, School of Chemical Engineering, Campinas, SP, Brazil; (2) State University of Campinas, School of Food Technology, Department of Food Technology, Campinas, SP, Brazil.

Biopolymers films have been considered a sustainable alternative to synthetic packaging The objective of this study was to optimize the formulation of gluten biofilms plasticized with glycerol, using response surface methodology (MSR). A 2(^3) complete factorial design with 6 axial points and 3 central points was used, considering the following independent variables: (i) wheat gluten concentration (2.5; 5.0; 7.5 and 12.5 g/100 mL), (ii) ethanol concentration (20; 32.5; 45; 57.5 and 70 mL/100 mL); (iii) pH (2, 3, 4, 5 and 6). The film forming solution was produced by mixing different amounts of gluten and ethanol, adding 20% of glycerol (w/w) and heating the solution to 75°C/5 minutes. The solution was then centrifuged at 5000rpm/20 minutes and the films made by casting. The dependent variables were: (i) water vapor permeability (WVP); (ii) solubility in water; (iii) tensile strength and (iv) percentage of elongation. ANOVA analysis indicated that the model was statistically significant for all responses studied. The increase of gluten concentration (2.5 to 12.5 g/mL) caused an increase in WVP, which varied from 5.44 to 12.72 g.mm/m(^2).day.kPa. The gluten concentration was the only significant variable (P < 0.05) affecting the solubility in water and an increase in gluten caused a decrease in solubility. Resistance to tension varied from 0.36 to 1.35 MPa, producing high resistance at the maximum protein concentration. The analysis also indicated that all range of pH values studied (2 to 6) could be used to obtain films with high elongation if the gluten concentration is above 7.5%. The films with the best attributes with respect to WVP and resistance to tension were obtained with 5% gluten, 32.5 mL ethanol and pH 5. We thank FAPESP for granting a scholarship to L. C. Bertan.

P-319
The role of cellular structure and phase behavior on the texture of extruded solid foams. L. Samuel (1), H. Dogan (1), J. L. KOKINI (1). (1) Rutgers University, New Brunswick, NJ, USA.

Understanding the impact of cellularity and phase behavior on texture of extrudates can result in rules to design the product better by configuring the extrusion process to obtain the desired level of crystalline to amorphous ratio and also to obtain the needed level of cellularity. The objective of this study was to investigate the effect of processing conditions on the formation of cellular structure and, the impact of cellularity and phase behavior on the texture of extrudates. 50:50 corn-wheat blend along with poultry meal was extruded under varying processing conditions to obtain extrudates of wide range of cellularity. Cross-sectional images of extrudates were obtained using X-ray microtomography and subjected to image analysis techniques to measure average cell size and cell size distribution, cell density, cell wall thickness and cell wall thickness-to cell radius ratio (t/R). Volumetric displacement techniques were used to quantify bulk and solid densities. Differential scanning calorimetry and wide-angle x-ray diffraction were used to determine glass transition temperatures (Tg) and crystalline to amorphous ratios respectively. Uniaxial compression was used for textural characterization. Average cell wall thickness of the extrudates decreased with decreasing ratios of specific thermal energy to specific mechanical energy (R(^2) = 0.87). Fracture stress increased as a power function of bulk density (R(^2) = 0.77). Number of peaks decreased with increasing t/R ratios (R(^2) = 0.55). X-ray diffraction patterns revealed a predominantly amorphous starch phase with relatively low crystalline to amorphous ratio (0.9–5.7%), attributed to the crystallization of amylose-lipid complexes during extrusion. Fracture stress decreased exponentially with increase in relative crystallinity (R(^2) = 0.67) and increased as distance from Tg increased (R(^2) = 0.64).

P-335
Effects of added ash on the pasting and noodle making properties of wheat flour. H. GUJRAL (1), B. Baik (1). (1) Washington State University, Pullman, WA, USA.

Ash content serves as an index of wheat flour quality to flour millers and food manufacturers, who prefer flour of low ash content even though its significance in functional properties of wheat flour is not well understood. We explored if ash has any influence on the processing properties of wheat flour and product quality. Ash obtained by incinerating wheat bran was incorporated into two hard white spring wheat flours having ash content of 0.46 and 0.45% to raise the total ash content to 1, 1.5 or 2%. Increasing ash to 2% increased the RVA peak viscosity of the flours by 7–15%, but lowered the peak viscosity of the isolated starch. The pH of the flour water slurries was increased from 6.0 to 7.8 with ash at the 2% level. The peak viscosity of the starch increased with the addition of gluten and further increased by the subsequent addition to 1% ash, possibly by promoting electrostatic interactions in protein molecules. Incorporation of ash up to 2% reduced the sheet length of white salted noodles by 7–16%, resulting in thicker noodles. With the addition of ash to 2%, water retention of cooked noodles decreased and firmness increased. The viscosities of wheat flours were >7% higher with ash added to 2%, even when the pH was kept constant by using a buffer solution. The peak viscosity temperature of flours decreased by about 10°C by ash addition to1%. Viscosity of starch in buffer solution increased by addition of ash to 2%, but it did not lower the pasting temperature of the starch.

P-337
Fortification of spaghetti with Lupinus mutabilis derivatives and rheological, processing, and quality evaluation studies. V. López-Santos (3), H. López-López (3), M. Reyes-Santamaría (3), S. Soto-Simental (3), G. Davila-Ortiz (2), R. Peña-Bautista (1), N. GUEMES-VERA (3). (1) Centro Internacional de Mejoramiento de Maiz y Trigo; (2) ENCB-IPN; (3) Instituto de Ciencias Agropecuarias-UAEH, Tulancingo, Hidalgo, Mèxico.

The aim of the present work was fortified with L. mutabilis derivatives durum wheat semolina. Protein (N × 6.25; method 955.04), lipids (method 920.39), crude fibre (method 962.09) and ash (method 923.03) were determined according to AACC 1995. Spaghetti was prepared from durum wheat semolina, fortified with 0, 5, 10, 15 and 20% of lupin flour (LF), 3, 5, 8 and 10% of lupin protein concentrate (LPC) and 0.5, 1, 2, 3 and 4% of lupin protein isolate (LPI) to increase protein. Later the rheological analyses (TPA and adhesiveness) were performed by using a TA.XT2i texture analyzer (Stable MicroSystems Ltd., Surrey, UK) in a compression mode. Supplementing semolina with LF, LPC and LPI caused an decrease in hardness and cohesivity of the dough except for blends containing 15 and 20% of LF, in the case of adhesivity, the fortification increase this property. For the extensibility and adhesivity force diminish between 15–20% of LF and 8–10% of LPC. Firmness scores of the fortified spaghetti increased with the level of fortification. Taste panel evaluation showed that spaghetti supplemented with 3% of LPI was acceptable. A beany taste and hardness was reported for this spaghetti with respect to the commercial.

P-344
Influence of hydration level and mixing time on rheological and structural properties of common and durum wheat milling fractions. V. LANDILLON (1), D. Cassan (1), M. Morel (1), B. Cuq (1). (1) Agro.M-INRA UMR IATE, Montpellier, France.

The aim of this work is to study the agglomeration mechanism of wheat milling fractions occurring at intermediate hydration levels (12–35%) and two mixing times (10 and 30 min). Two common wheat flours (55 and 110% extraction rates), one durum wheat groat and one durum wheat semolina are selected from different physical and biochemical characteristics. The cohesion properties and the morphology of the wheat millings before and after mixing with water were determined using the powder flow analyser under compaction and shearing stresses and the environmental scanning electron microscopy (ESEM). Different agglomeration products, in terms of size and cohesion, were observed in relation with the physical and biochemical characteristics of wheat millings. Under our experimental conditions, no dough formation occurred. Short mixing time and intermediate water contents induced heterogeneous particles hydration. Slightly swollen starch granules were observed while many others appeared unchanged. Low water contents (<20%) lead to weak but discriminative cohesion for the different wheat milling particles. Under compaction, common flours and durum groat were cohesive contrary to durum semolina (higher particle size). After shearing, only the durum groat remained cohesive, probably due to biochemical composition even if no relationship was clearly found. At higher water contents (>20%), the cohesion properties were similar for all the wheat millings. This was probably associated to the reactivity of particles that tended to form cohesive interactions such as liquid bridges and hydrogen bondings. Moreover, drastic cohesion changes associated to a critical reactivity threshold were observed for all wheat millings between 25 and 30% water content.

P-346
Noodle quality affected by different cereal starches. Y. Huang (1), H. LAI (1). (1) Dept. Agric. Chem., National Taiwan University.

Different sources of cereal starches, including rice, wheat and corn, were used as the substituted starches of reconstituted flour for udon noodle making. The effects of starch properties on the noodle making and its eating and storage qualities were evaluated. The dough sheets made from reconstituted flours had similar initial stress of wheat dough which was prepared by adjusting the water absorption of flour. The results show that dough sheet made from rice starch was the most compact and the least thickness, while their percentage of relaxation increased compared to others. The optimal cooking time was much shorter for noodle made from rice starches than other samples. The low cooking loss of noodle made from rice starches was attributed to the short cooking time, while the short cooking time resulted in low moisture content and low swelling index of boiled noodle. The noodle made from waxy rice and waxy corn starches had good storage quality up to 1 day storage at 4°C. which show low cutting force of noodles. The cutting force increased significantly for noodles made from rice starches than others after 5 days of storage.

P-350
Evaluation of commercial spaghetti texture at different cooking and resting times. A. COTA-GASTÉLUM (2), M. Salazar-García (2), A. Islas-Rubio (1). (1) Centro de Investigación en Alimentación y Desarrollo. Hermosillo, Sonora, México; (2) D.I.P.A.Universidad de Sonora, Hermosillo, Sonora, México.

Texture is generally accepted as the main criteria to evaluate the quality of cooked pasta. Commercial spaghetti was cooked at different cooking times (9.5, 12.5, and 15.5 min) and allowed to rest for 2 and 5 h. The effect of cooking and resting times on texture and physicochemical parameters such as water absorption index, total solids, amylose content and total organic matter of cooked spaghetti were evaluated. Spaghetti firmness (as maximum force) and work of deformation (as area under the curve) were determined using the texture analyzer TA-XT2. Spaghetti firmness was significantly affected by cooking and resting times. On the other hand, cooking time showed a significant effect on the physicochemical parameters evaluated; in addition, significant correlations between these parameters and maximum force and work of deformation were found. This suggests that maximum force provides a good estimate of the texture of cooked spaghetti.

P-358
Effect of flour moisture level on biscuit flour functionality. W. CHUNG (1), N. Zhou (1), L. Haynes (1), T. Hansen (2). (1) Kraft Foods, East Hanover, NJ, USA; (2) Kraft Foods, Glenview, IL, USA.

Moisture level in biscuit flour and dough is important for baking functionality. Especially, flour moisture level can be one of the critical factors for a few characteristics such as enzyme activity and gluten development. The objective of this study was to determine the effect of moisture level in biscuit flour on dough rheology and baking functionality. White biscuit flour at three different flour moisture levels (low, medium, and high) were evaluated with AACC cookie test baking (10-53). Dough rheology of these flours was measured at the same time. The dough moisture content was controlled in the same level, by adjusting formula water. Results showed that the firmness and toughness of dough increased from 116 to 161 g and from 612 to 849 g.s, respectively with the increase of flour moisture. Meantime, the stickiness of dough also increased as the flour moisture level increased. Stress relaxation of these dough indicated that the relaxation time also increased with the flour moisture. All these results suggested that the dough could develop more network as the flour moisture increases. The baking test showed that the cookie spread more at lower flour moisture, the width and length ranged from 35.1 to 35.9 cm and from 34.9 to 35.7 cm as flour moisture decreases, indicating that cookie geometry or spreadability was affected by flour moisture level. In addition, cookie stack height increased with the flour moisture confirming the effect of flour moisture on cookie geometry. These results suggested that flour moisture level plays a critical role in biscuit flour functionality.

P-359
Effect of starch crystallinity on the mechanical properties of dry and hydrated baked cereal foams. E. LABAT (1). (1) Nestle Research Center, Lausanne, Switzerland.

Dry baked cereals foams with a crisp texture are highly appreciated by consumers. Moisture management in these products is essential for their shelf life. Our aim was to investigate the impact of starch crystallinity on the mechanical properties of baked foams as a function of water activity. Dry baked wheat flour foams were prepared using a hot plate oven, leading to a fully gelatinisation of the starch fraction. The foams were stored at different conditions to generate the crystallisation of amylopectin chains. Storage was performed under controlled conditions to achieve different moisture contents and different temperatures. After storage samples were dried under gentle conditions. Thermal analysis of the products after storage, revealed an endothermal transition between 60 and 90°C, related to the melting of the amylopectin crystals. This endothermal transition varied according to the storage conditions, with enthalpies reaching up to 2.8 J/g starch. Moreover, the higher was the storage temperature, the higher was the melting point, indicating a change in crystal structure. Samples were rehydrated under controlled conditions of humidity and mechanical properties were assessed using a puncture test. The number of peaks (Nsr) with amplitude higher than 0.2 N was recorded. This method has previously been shown to correlate with sensory attributes. Irrespectively of the product, hydration induced a decrease in Nsr, which can be correlated to a loss of the product crispiness. The retrograded samples were characterised by higher Nsr than the control. The impact depends on the extend and crystal type formed during storage. The effect of crystalline amylopectin in modifying the mechanical properties of hydrated amorphous flour matrices has been demonstrated.

P-362
Relationship between hardness and internal structure of high fiber content extruded snacks. R. E. Ferreira (1), Y. K. Chang (1), C. J. STEEL (1). (1) UNICAMP, Campinas, SP, Brazil.

The development of high fiber content extruded snacks is a means of supplying healthier products to consumers. The texture of extruded snacks has a great influence on the acceptability of the product and is related to the conditions used during the extrusion process. These conditions also affect the internal structure of the extrudates. The objective of this study was to evaluate the influence of raw material moisture content, process temperature and percentage of wheat bran on hardness values and to relate this parameter to the internal structure of the extrudates. Hardness was determined using a TAXT2 texture analyzer and internal structure was visualized through Scanning Electronic Microscopy (SEM). A central composite rotational design (CCRD) was used to evaluate the effect of the different variables. The independent variables studied were: moisture content (16.3–29.7%), third zone temperature (104.8–155.2°C) and bran content (0–24.6%). It was observed that the lowest moisture contents, the highest temperatures and the highest levels of wheat bran resulted in less hard snacks. Using SEM, it could be observed that high moisture contents resulted in snacks with a dense structure and poor cell formation; high temperatures contributed to the weakening of the structures; and high fiber contents lead to the formation of a great number of incomplete cells with thin walls, resulting in a fragile structure and a smoother texture. According to the results, it cannot always be affirmed that the addition of fibers, which results in a lower expansion, produces harder extrudates. It depends on the variables involved and their relationship.

P-368
Study of the application of yacon (Polymnia sonchifolia) flour and flaxseed flour in pound cake by surface of response methodology. A. L. Marangoni (1), F. P. COLLARES (1). (1) State University of Campinas, Department of Food Technology, Campinas, SP, Brazil.

Lately, the food market has shaped itself as a function of the food quality and nutritional value. Yacon is recognized as an important nutraceutical food, due to its functional properties related to its high level of fructo-oligosaccharides. This study assesses the application of yacon flour (obtained from raw roots) and flaxseed flour, which contains alpha-linoleic fatty acid, lignans and soluble an insoluble dietary fibers, to produce pound cakes with physiological functionality. A response surface methodology has been adopted to create 12 trials, including 4 axial points and 4 central points. The two independent variables could assume 5 different values each: yacon flour (X(1)) and flaxseed flour contents (X(2)). Dependent variables were physicochemical (moisture, instrumental texture and color, dough density and specific volume) and sensorial properties (global and crumb appearance, texture, flavor and acceptability). Experimental data were submitted to analysis of variance (ANOVA). Only the parameters, instrumental texture (hardness attribute); color (L*, C* and h*) and dough density generated valid statistical models. Generated surfaces suggest that yacon flour content range from 0.0% to 3.45% and flaxseed flour levels between 3.18% and 6.0% provided cakes with lower hardness. In relation to color parameters, minimum concentrations of yacon and flaxseed flours (0.0% and 3.18%, respectively) resulted in higher values for these parameters, that is, the cakes presented a clearer and more yellowish color. The dough density reached lower values when flaxseed flour level was 6.0%, but the yacon flour level had no influence. Thus, the addition of yacon and flaxseed flours, at concentrations of 3.45% and 6.0%, respectively, result in a cake with more desirable characteristics.

P-372
Effect of biodegradable edible coatings on physical-chemical properties of chocolate pound cake. L. B. Fontes (1), C. C. Osawa (1), E. M. Walter (1), C. J. Steel (1), Y. K. CHANG (1). (1) UNICAMP, Campinas, SP, Brazil.

Biodegradable edible coatings are an alternative to replace synthetic packages that cause environmental concerns. This work evaluated the effect of edible coatings on physical-chemical properties of chocolate pound cake during storage, in comparison to cakes without coating (C) and cakes without coating packaged in polypropylene (CP). Chocolate flavored pre-mix was used to prepare the cakes. The following coatings were applied on the surface of the cakes after baking: 10% gelatin (GE), 10% gelatin and 10% stearic acid (SA), 18% “carnaúba” wax (CW), 10% modified starch (MS) and chocolate fudge (CF). The cakes were analyzed during 10 days storage at 28.2°C and 93.2% RH. The results were analyzed by ANOVA and the Tukey test (P < 0.05). CF and CP presented the lowest mass loss, while all other trials presented higher values than C. GE, SA and CP presented the lowest reduction of water activity, while CF and C presented the highest. The highest values for hardness and chewiness (TPA, probe P/100) were found for C and CW and the lowest were found for CP and GE. The surfaces of the coated cakes were harder (perforation, probe P/2) than C and CP. With respect to color (CIELab), SA was different to the remaining cakes, due to the presence of stearic acid that conferred a white color to the coating. The results indicated that the mass loss of the cakes could be mainly attributed to the loss of water from the coatings. The coatings evaluated may effectively prevent dryness of the cakes, maintaining them with desirable texture properties, except for CF. This may be attributed to the high concentration of sugar in the fudge that absorbed water from the cake.

P-373
Effect of the extrusion parameters and yacon (Polymnia sonchifolia) flour content on the quality of rice flour snacks. A. L. Marangoni (1), F. P. COLLARES (1). (1) State University of Campinas, Department of Food Technology, Campinas, SP, Brazil.

In this work, rice and yacon (Polymnia sonchifolia) flours were extruded for the production of snacks in a pilot single screw extruder INBRAMAQ (São Paulo, Brazil), model Labor PQ-30. The raw roots used to produce the yacon flour contain the following chemical composition: 88.38% moisture, 0.14% protein, 0.06 lipids, 0.03 ashes and 8.42% carbohydrates. The yacon flour obtained, in turn, presented 5.94% moisture, 2.02% protein, 0.11% lipids, 4.12% ashes and 83.87% carbohydrates. A response surface methodology has been adopted to create 12 trials, including 4 axial points and 4 central points. The three independent variables could assume 5 different values each: yacon flour concentration (X(1): 12, 15, 20, 25, and 28%), feed material moisture content (X(2): 17, 18, 20, 22 and 23%), and temperature of the 4th and 5th extruder zones (X(3): 103, 110, 120, 130, and 137°C). Dependent variables were physicochemical (texture and instrumental color, moisture, water absorption index and water solubility index, expansion rate) and sensory properties (appearance, texture, flavor and buying intention). The snacks produced with greater expansion rate values (R(^2) = 0.70) were obtained at 120°C, with 17% material moisture content and 12% yacon flour content. For the sensory texture and buying intention, the R(^2) was 0.87 and 0.72, respectively. The surfaces generated show that the maximum value for these last attributes occurred for the same conditions of temperature, moisture of raw material and yacon flour content as for expansion rate. The yacon flour content did not have, however, significant influence (P < 0.05) in buying intention.

P-375
Influence of flour chlorination and ingredient formulation on the quality attributes of pancakes. S. M. FINNIE (1), A. D. Bettge (1), C. F. Morris (1). (1) USDA-ARS WWQL, Pullman, WA.

Soft wheat flour is chlorinated in North America for the production of cakes and pancakes. The oxidative properties of chlorine gas cause chemical modifications to flour components that enhances processing and end-use functionality of the intended food products. The objectives of this study were first, to compare how untreated and chlorine-treated commercial soft wheat flour performs in a standard pancake formulation and second, to compare how the individual ingredients in a standard pancake formulation influence quality attributes of pancakes made with untreated as well as chlorine-treated commercial soft wheat flour. Two identical soft wheat flour samples, one chlorinated and the other unchlorinated, were used to study the flour chlorination effects on the quality attributes of pancakes, as determined by texture meter analysis and viscosity. Commercial pancake mixture ingredients were evaluated at different concentrations for their individual influence on quality attributes of pancakes. Differences (ANOVA) in means were used to evaluate the influence of the sources of pancake quality variation. The results indicate that flour chlorination had a significant influence on pancake batter viscosity, geometry and texture, with chlorinated flour unsurprisingly producing a consistently superior product. The evaluation of different ingredient concentrations indicated that no modification among pancake formula ingredients could wholly substitute for chlorination. Individual ingredients did dramatically influence pancake batter viscosity, geometry and texture (i.e. soy flour, dextrose, and the leavening agents). However, sucrose and shortening had insignificant influences on the end-use quality in both chlorinated and unchlorinated pancakes.

P-377
Ozonation of cake flour as an alternative to chlorination. S. CHITTRAKORN (1), F. MacRitchie (1). (1) Department of Grain Science and Industry, Kansas State University, Manhattan, KS, USA.

Ozonation was studied as an alternative to chlorination for cake flour. Non chlorinated flour was treated with ozone at the rate of 0.06 L/min for 10 and 36 minute using 5 lb of flour. Ozonation of cake flour decreased pH and increased the lightness (L value) of flour comparable to chlorinated cake flour. As time of ozonation increased from 10 to 36 min, pH of flour decreased from 6.07 to 5.96 and 5.66 respectively. Baking studies using a high-ratio white layer cake formulation showed that cake batter viscosity increased as ozonation time increased and ozonated treatment of flour improved cake volume and increased brightness of cakes. As the time of ozonation increased from 10 to 36 min, the volume of cake significantly increased (P < 0.05) and the 10 min ozonation time gave similar volume to chlorinated cake flour. Cakes prepared with ozonated flour were significantly softer than chlorinated and non chlorinated flour (P < 0.05). The springiness and cohesiveness of cake from ozonated flour gave similar values to cake produced from chlorinated flour. Study of cake cell structure using C-Cell showed that cell brightness and number of cells of cake from ozonated flour exhibited similar values to those from chlorinated flour.

O-02
Fracture and acoustic emission of crisp foodstuffs
Presenter: J. Visser, Wageningen Centre for Food Sciences and Wageningen UR, Wageningen, Netherlands
Co-Author(s): H. Luyten, Wageningen Centre for Food Sciences and Wageningen UR, Wageningen, Netherlands; W. Lichtendonk, Wageningen Centre for Food Sciences and Wageningen UR, Wageningen, Netherlands; R. Hamer, Wageningen Centre for Food Sciences, Wageningen, Netherlands

Despite its importance for many foods the concept of crispness is still poorly understood. It is clear that crisp behaviour is related to fracture behaviour. Crispness is characterised by multiple fractures accompanied by the emission of sound. In this study we explored the additional information gained from analysing both mechanical and acoustical data at a high sampling rate. The crispness of many foods is readily lost due to redistribution of water and/or water uptake due to exposure to humid air. In this presentation we will discuss a method to measure the changes in fracture behaviour and acoustic emission during storage of different crisp foodstuffs and how to quantify these changes. The foods were penetrated at 40 mm.s(^–1) with a wedge shaped probe using a Stable Micro Systems TAXTplus texture analyser. The force needed for penetration was recorded at a sampling rate of 65 kHz. Moreover, the audible sound emitted during the wedge penetration was recorded at the same sampling rate. Such a high sampling rate is found to be necessary for a full characterisation of the fracture behaviour of a crispy product under conditions as in the mouth. Both the force vs. time and the sound pressure vs. time graphs show a clear decrease in jaggedness when the crispness of the foods decreased. The characterisation of this jaggedness in number and size of peaks provides insight in the changes occurring upon storage. In general, higher energy dissipation during deformation of the product resulted in less major fracture events. A decrease in the amount and amplitude of acoustic events was found when crispness of foods decreased. In our opinion the fracture behaviour, the acoustical properties and the relation between them provide useful information on the mechanisms of crispness.

O-03
Impact of hydrocolloids on the texture and sensory profile of instant noodles
Presenter: M. Cash, Aqualon, Wilmington, DE
Co-Author(s): S. Caputo, Aqualon; J. Goodall, Aqualon; J. Morehouse, Aqualon

Instant Noodles were prepared with CMC or guar. The impact of CMC degree of substitution, molecular weight and use level on texture and organoleptic properties of the noodles was measured. Since guar is underivatized, only molecular weight and use level were examined. Tension and compression tests were conducted using a texture analyzer in order to quantify textural characteristics of the noodles. An experimental design was also used to correlate sensory attributes of the products with texture analysis results. Attributes measured were adhesiveness, firmness, chewiness, and resilience. Fat analysis was also conducted using a solvent extraction method. It was determined that more highly substituted CMC increases the firmness and adhesiveness of instant noodles while reducing the chewiness and resilience. Similarly, higher molecular weight CMC also contributed to greater firmness and adhesivity while reducing chewiness and resilience. Surprisingly, fat absorption increased as DS increased but decreased as molecular weight increased. In the samples prepared with guar gum, the firmness, adhesiveness and resilience decreased with increasing molecular weight while only the chewiness increased. Fat uptake decreased as the molecular weight of the guar increased. Finally, a comparative analysis of 23 commercial products from 8 Asian countries was also conducted in order to correlate sensory panel perceptions with CMC type and use level required in order to achieve the desired perception.

O-08
The effect of lipases on the texture colour and structure of white salted noodles made from Australian white wheat flour
Presenter: L. Cato, RMIT University, Applied Sciences/Applied Chemistry, Melbourne, VIC, Australia
Co-Author(s): D. Small, RMIT University, Applied Sciences/Applied Chemistry, Melbourne, VIC, Australia; A. Halmos, RMIT University, Applied Sciences/Applied Chemistry, Melbourne, VIC, Australia

White salted noodles are a major end use of wheat flour worldwide. The potential role of endogenous enzymes found in wheat flour and also those that might be added to noodle formulations are yet to be elucidated. It has been reported that lipase has some positive effects on the quality attributes of baked products. Although processing of breads and noodles is quite different some effects of lipases might be expected if small amounts of these enzymes are added into the noodle formulation. The aim of the current study has been to examine the effect of exogenous lipases from three different sources (wheat germ, porcine pancreas and fungal lipase derived from a selected strain of Rhizopus oryzae) on the colour and textural properties of white salted noodles. Texture was investigated using the Stable Micro Systems Texture Analyser (TA-XT2) with a cylindrical probe (P/45) and a cutting attachment. Noodle sheets were measured using the Minolta Chroma Meter (CR300), while structural characteristics of noodles were studied using the Scanning Electron Microscope (SEM & ESEM) Phillips XL 30. The activity levels of lipase were similar among the flours analysed. No losses were recorded upon the storage under defined conditions. Incorporation of the exogenous lipases had a greater impact on colour, although there were effects on texture and structure of the noodles. The wheat germ and fungal lipase preparations caused adverse changes in colour. There were also differences in surface appearance with some effect on starch due to the enzyme preparations. Noodles were softer upon addition of each of the three lipases.

O-49
Effect of incorporation of texture modifiers on textural and sensory qualities of lentil based extrudates
Presenter: R. Patil, WSU
Co-Author(s): J. Berrios, USDA-WRRC, Albany, CA; J. Tang, WSU, Pullman, WA; B. Swanson, WSU, Pullman, WA; J. Pan, USDA-WRRC, Albany, CA

Lentils are nutritionally very rich food. However, the acceptability of snack type products from lentils is affected by their chewy texture and the presence of beany flavor/taste. Due to its mild flavor, lentils can easily mix with special texture and sensory modifiers to improve the characteristics of the final product. Therefore, to remove the two main indicated draw backs, four types of texture modifiers were added in four different proportions to formulated lentil flours. The lentil formulations as well as specific extrusion processing parameters were developed to prepare expanded ball shaped breakfast cereal and rod shaped snacks. The major ingredients in the feed were lentil flour, starch and plant fibers. The feed with added texture modifiers were extruded on a twin screw extruder operated at different screw speeds. The instrumental texture profile analysis of the products was conducted with TX-TA2 texture analyzer. The textural parameters evaluated for the product from force deformation curve were hardness, fracturability, springiness, cohesiveness, gumminess, chewiness and resilience. Large-scale sensory tests were conducted on the lentil extrudates. The textural profile of the extrudates was comparable with sensory texture characteristics judged by the panel of testers.

O-75
Protein composition of wheat as related to the texture of Chinese raw noodles
Presenter: R. Saini, Michigan State University, East Lansing, MI
Co-Author(s): G. Hou, Wheat Marketing center, Portland, OR; P. Ng, Michigan State University, East Lansing, MI

Protein composition and its relationship with breadmaking quality of wheat flour have been extensively studied but limited information is available on the effect of wheat proteins on the quality of noodles. It is important to establish correlations between wheat protein components and noodle quality parameters to help breeders efficiently screen wheat during breeding stages. The objective of this study was to establish relationships between wheat protein quality and texture of Chinese raw noodles. Protein compositions of 22 wheat flour samples, differing in their noodle making properties, were determined using size exclusion HPLC technique. Textural properties of Chinese raw noodles were obtained using texture profile analysis (TPA). Protein content, polymeric proteins (peak I of HPLC fractions), monomeric proteins (peak II) and ratio between polymeric and monomeric proteins were related to the TPA parameters. Positive correlations exist between peak I and peak II proteins and the springiness of noodles. Hardness, gumminess and chewiness of the noodles were found to be positively related to Peak III proteins, whereas the peak IV proteins showed negative correlations with most of the textural parameters. Total protein content of wheat flour showed strong positive correlations with hardness, springiness, gumminess and chewiness of noodles.

P-118
A reduced-calorie flour containing type 3 resistant starch used in a model cracker system
Presenter: L. Haynes, Kraft Foods, East Hanover, NJ
Co-Author(s): M. Kweon, Kraft Foods, East Hanover, NJ; N. Zhou, Kraft Foods, East Hanover, NJ; L. Slade, Kraft Foods, East Hanover, NJ; H. Levine, Kraft Foods, East Hanover, NJ; J. Locke, Kraft Foods, East Hanover, NJ; S. Anderson, Kraft Foods, Glenview, IL

A reduced-calorie flour replacer containing type 3 resistant starch, made from a process comprised of a gelatinization, nucleation/propagation, and heat treatment stage for an amylose extender corn starch (aeWx VII), was evaluated in a cracker formula. Details of our preferred, patented process and flour replacer performance in a cookie formula have been published (1–4). The densified, recrystallized starch has increased total RS yield and reduced water-holding capacity and contains high-melting RS3, which was used to replace 50% of the flour in a cracker formula. Superior baking characteristics were the result, such as cracker crispness and golden brown color, comparable to those achieved with conventional soft wheat flour, in contrast to commercially available RS ingredients used at such a high level. In addition, the high melting point of this RS permitted its use in cracker formulations, without substantial loss of enzyme resistance upon baking. Differences in dough sheet toughness and extensibility, compared to control, were noted.

P-132
Effects of addition of wheat flours and transglutaminase on pseudocereals-based cracker qualities
Presenter: K. Jurackova, Department of Food Sciences and Technology, University of Natural Resources and Applied Life Sciences, Vienna, Austria
Co-Author(s): R. Schoenlechner, University of Natural Resources and Applied Life Sciences; E. Berghofer, University of Natural Resources and Applied Life Sciences; P. Ng, Michigan State University, Department of Food Science and Human Nutrition, East Lansing, MI

In recent years, the cultivation of pseudocereals has gained rising attention. This is mainly due to their attractive nutritive values and efforts to expand utilization of the number of species contributing to human nutrition. Three pseudocereals are of major importance worldwide: amaranth (Amaranthus sp.), quinoa (Chenopodium quinoa) and buckwheat (Fagopyrum esculentum). Amaranth, quinoa and buckwheat flours were used in this study. The influence of strong wheat protein flour, blended wheat flour (mixture of strong and weak wheat protein flours, 50/50) and the transglutaminase enzyme on the functional properties (weight, length, width, thickness, volume, moisture and hardness) of pseudocereals-based crackers were studied. Results of transglutaminase addition showed generally negative effects. Addition of the strong wheat flour increased the hardness of amaranth crackers and decreased the weight of quinoa crackers. The best crackers, compared to commercial whole wheat flour crackers using statistical analyses (Statgraphics®Plus 5.0), were obtained with (1) blended amaranth and strong wheat flours at a 40/60 ratio and 42% water content, (2) blended buckwheat and strong flours at 40/60, 45/55 and 50/50 ratios and 42–46% water content, and (3) blended buckwheat and strong-weak wheat flour blend at 40/60, 45/55 and 50/50 ratios and 42–46% water content.

P-133
The effects of different formulations on physical properties of doughs and breads baked in microwave and infrared-microwave combination ovens
Presenter: G. Sumnu, Middle East Technical University, Food Engineering Dept., Ankara, Turkey
Co-Author(s): O. Keskin, Middle East Technical University, Food Engineering Dept., Ankara, Turkey; S. Sahin, Middle East Technical University, Food Engineering Dept., Ankara, Turkey

The aim of this study was to investigate the effects of gums and emulsifiers on physical properties of doughs and breads baked in microwave, infrared-microwave combination and conventional ovens. The physical properties investigated in this study were the rheological properties of dough (extensibility and stickiness) and the firmness, specific volume, weight loss and color of breads. The emulsifiers used were Purawave and DATEM, and the gums used were guar gum, xanthan gum, and kappa (k)-carrageenan. The emulsifiers and gums were added to the formulation at 3% and 1% respectively. The extensibility of doughs with emulsifiers and gums were higher than that of the dough with no additive. It was found that all the gum and emulsifier types decreased the dough stickiness. When quality parameters were considered, it was seen that the effect of gum or emulsifier addition were not significant on the weight loss, specific volume, firmness and color of breads baked in microwave oven. When infrared-microwave combination oven was used, all the gums and DATEM used in this study were found to be effective on reducing weight loss, and additionally DATEM and Purawave were found to be effective on reducing bread firmness and improving specific volume of breads. Breads baked in combination oven had similar quality with conventionally baked ones, except weight loss. Any significant change in bread color were not observed for different formulations.

P-135
Influence of starch-lipid composites on chocolate chip cookies
Presenter: M. Singh, USDA-ARS-NCAUR, Peoria, IL
Co-Author(s): F. Felker, USDA-ARS-NCAUR, Peoria, IL; G. Fanta, USDA-ARS-NCAUR, Peoria, IL

Obesity is not only on the rise among adult Americans, but is becoming a concern for children also. Reduction in dietary fat is known to decrease body fat. There is a need to increase the acceptability of healthier choices for popular foods and snacks. The objective of this study was to investigate the use of starch-lipid composites to replace butter in chocolate chip cookies. Cookies were prepared using a recipe based on the popular "toll house" style of chocolate chip cookies, but without the chips. Two types of jet-cooked starch-butter composites (liquid and dry) were used to replace 10, 20, 30, and 40% of the butter in the recipe. The reduction in fat changed the characteristics of the cookies in comparison to the full fat version. Cookies with fat replaced by starch-lipid composites were lighter in color, chewier and moister than full fat cookies. The changes in color and texture brought about by the addition of starch lipid composites can be rectified by adjusting the other ingredients (mainly sugars), baking time and baking temperature. Fat replacement with starch-lipid composites provides a healthier alternative product to consumers.

P-139
Acid modified starches from conventional and non-conventional sources: Pasting and texture properties
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): C. Osawa, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; L. Bertan, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; I. Cardoso, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; C. Steel, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil

Starch is a natural polysaccharide found in cereals, legumes, roots and tubers. It can be used in diverse applications in the food industry. Chemically modified starches are extensively used and molded according to the technological needs of a specific application, stressing positive attributes and/or diminishing undesirable characteristics. Acid modified starches generate low viscosity starches that can be used at higher solid concentrations than native starches, easing some technological applications. The goal of this work was to characterize conventional (corn and cassava) and non-conventional (sweet potato, yam, white bean, Carioca bean, ginger, chickpea and Peruvian carrot) starch sources, chemically modified with 0.3 N hydrochloric acid, at 40°C, during 1 hour. Gel strength, peak viscosity (PV), minimum viscosity (MV), the ratio between PV and final viscosity (FV), setback and pasting temperature were determined using a TAXT2 Texture Analyzer and a Rapid Visco Analyser (RVA). PV and MV values varied from 2338 to 6175 cP and from 588 to 3757 cP, respectively. The PV/FV ratio increased for cassava, corn and Carioca bean and decreased for sweet potato and white bean. The greatest setback value was observed for modified yam starch and the lowest value was observed for Peruvian carrot. Pasting temperatures varied from 61.4 to 88.2°C. Gel hardness ranged from 61.5 to 1295.2 g, the higher values corresponding to legume sources, followed by roots and tubers, except for yam and corn. Pasting and texture properties indicated that different sources of starch show different susceptibilities to acid modification.

P-140
Addition of glucose, sucrose and fructose to pastes prepared from starches extracted from non-conventional sources: Changes in rheological properties
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): C. Pinho, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; D. Becker, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; D. Cavalcante, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; C. Steel, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil

Starch is considered a functional food additive due to its contribution to product texture. Knowledge of starch pasting properties is extremely important for its industrial applications. Pasting and texture properties of starch extracted from non-conventional sources (Peruvian carrot, yam, common bean, chick-pea, ginger and sweet potato) were studied in this work using the Rapid Visco Analyser (RVA) and the TAXT2 Texture Analyser, respectively. Glucose, sucrose and fructose were added to the starches at ratios of 1:1 and 1:3 (starch:sugar, w/w). The quantities used to prepare the pastes were calculated in order to keep a 12% solids content. Results showed that different concentrations of the same sugar significantly modified starch pasting properties (P < 0.05). In the majority of samples analyzed, the addition of sugars at a ratio of 1:1 showed a greater effect in increasing peak viscosity, breakdown and setback than the addition of sugars at a ratio of 1:3. However, the comparison between different sugars, considering the same starch:sugar ratio, did not result in statistically significant differences for the majority of samples analyzed (P < 0.05). Texture analyses of starch pastes with added sugars at a ratio of 1:1 confirmed that sugar addition increases the tendency to retrogradation.

P-153
Pasting properties of starches from non-conventional sources compared to maize and cassava starches
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): D. Kabeya, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; K. Gandra, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; E. Pilarski, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; C. Steel, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil

Starches of major economic importance are those found in roots and cereals. The need of exploring and studying amylaceous raw materials is verified, especially in Brazil, that has a privileged geographic localization for the production of different cultivars. Legume and non-conventional tuber starches have not been extensively used in the industrial sector due to a lack of knowledge of their functional properties. In this study, starches were extracted from tubers and legumes of the following varieties: Dioscorea alata (yam), Arracacia xantorrhiza Banc (Peruvian carrot), Phaseolus vulgaris L. (common bean) and Cicer arietinum L. (chickpea). Their pasting properties were studied using the Rapid Visco Analyser (RVA). Commercial maize and cassava starches were used as references. Pasting temperatures ranged from 63.9°C for Peruvian carrot to 79.5°C for common bean. Peak viscosity was highest for Peruvian carrot starch (471.09 RVU), similar to cassava starch (492.36 RVU). Yam, common bean and chickpea presented intermediate values (399.28, 373.42 and 333.78 RVU, respectively), while maize starch had the lowest peak viscosity (246.97 RVU). The retrogradation tendency (setback) of legume starches was much higher (247.56 RVU and 245.75 RVU, for common bean and chickpea, respectively) than that of cereal (97.06 RVU for maize) and tuber (186.97 RVU for yam, 44.64 RVU for Peruvian carrot and 76.89 RVU for cassava) starches. Cassava and Peruvian carrot starch pastes presented higher breakdown values, indicating greater fragility to agitation. These differences in rheological properties reflect differences in the composition of the starches and their knowledge is crucial to define applications in food products.

P-155
Physico-chemical characterization of starch gels following microwave heating
Presenter: K. Seetharaman, Penn State University, State College, PA
Co-Author(s): T. Palav, Penn State University, State College PA

In spite of the advantages of microwave energy for food processing, overall product quality of microwave baked products remains inferior to conventional baking. The objective of this work was to understand physical and chemical changes induced in wheat starch model system, at higher starch concentrations, following microwave heating. Wheat starch at 33%, 40% or 50% solids content was heated in a microwave oven at 1140W. Following heating the samples were stored at 25°C for up to 120h and analyzed periodically. All the samples attained temperatures of 95°C within 10s. The modulus of elasticity of gels decreased successively with increasing heating times and decreasing solids content. The amount of reducing sugars produced by action of alpha amylase on lyophilized samples decreased with increasing heating times and decreasing solids content. The amylopectin recrystallization and swelling power of lyophilized samples increased with increasing heating times and solids content. The onset of pasting temperature increased with increasing heating time and decreased with decreasing solids content. Furthermore, the final viscosity of paste decreased with increasing initial moisture content. The vibrational motion of the water molecules due to microwave energy appears to have melted starch into a continuous mass as is evident from observations using scanning electron microscopy. Such interactions of microwave energy with the polymers could potentially be the cause for the differences in gel properties following microwave and conventional heating. A better understanding of starch properties as a function of microwave heating will aid in designing process for microwavable baked products with improved quality, reduced process times and reduced production costs.

P-158???
Stability of native starch gels from different non-conventional sources through the freeze-thaw cycles
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): R. Ormenese, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; C. Takeiti, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; F. Fakhouri, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; C. Steel, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil

Starch is a useful ingredient in the formulation of ready-to-eat or ready-to-use foods. There is great interest in evaluating the stability of the gels of different types of starches, when submitted to freezing and thawing, to assure the final quality of these products. In this work, the stability of starch gels from non-conventional sources (Peruvian carrot, sweet potato, white bean and chickpea), submitted to five freeze-thaw cycles, was studied through the evaluation of texture characteristics and water release (syneresis). The results were compared to commercial starch gels (native, waxy maize and modified waxy maize). Peruvian carrot and waxy maize starch gels were stable until the third freeze-thaw cycle, while sweet potato starch gel was unchanged until the fourth cycle. During the experiment, Peruvian carrot starch gel lost 5% water (maximum), and waxy maize and modified waxy maize starch gels released 8 and 12%, respectively. Native maize, chickpea and white bean starch gels showed high water loss already in the first cycle. The texture characteristics of sweet potato and Peruvian carrot starch gels showed greater hardness than waxy maize and modified waxy maize gels during all the research period. Until the fourth freeze-thaw cycle, modified waxy maize and Peruvian carrot starch gels did not show statistically significant differences (P < 0.05) in terms of hardness. After the first freeze-thaw cycle, the hardness of the sweet potato starch gel remained unchanged. This was also observed with white bean and chickpea starch gels.

P-161
Texture profile analysis of starches from non-conventional sources compared to maize and cassava starches
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): K. Gandra, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; D. Kabeya, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; E. Pilarski, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; C. Steel, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil

Starch is a versatile ingredient in the food industry, being widely used as a thickening, gelling, bulking and water retention agent. The knowledge of the textural properties of different starches is therefore very important, to correctly select the best starch for a determined application. The present investigation was undertaken to study the texture characteristics of gels from different non-conventional starch sources, in comparison to widely studied native cereal (maize) and tuber (cassava) starches. Non-conventional starches were extracted from two tubers and two legumes of the following varieties: yam (Dioscorea alata), ginger root (Zingiber officinale), chickpea (Cicer arietinum L.) and white bean (Phaseolus vulgaris L.). A TAXT­2 texture analyzer was used to study the texture profiles of the starch gels. The textural properties of the gels from the different starches varied greatly. Hardness was greater for the gel prepared with yam starch (483.7 gf). Ginger root (426.8 gf), chickpea (382.9 gf) and white bean (360.3 gf) starch gels had intermediate hardness values. Maize (92.7 gf) and cassava (54.3 gf) starch gels had much lower hardness values. The most cohesive gel was that from cassava (0.91). Maize starch gel had an intermediate value for cohesiveness (0.56). Yam (0.49), chickpea (0.46), white bean (0.46) and ginger root (0.46) starches were less cohesive. With respect to gumminess, the yam starch gel presented the highest value (235.5). Ginger root (198.4), chickpea (175.4) and white bean (166.6) starch gels had intermediate values. Cassava (48.9) and maize (52.2) gels were less gummy. These results confirm the need of in-depth studies to determine the applicability of new starches as textural ingredients in the food industry.

P-187
Extrusion of whole-grain and milled specialty sorghums
Presenter: A. Perez-Gonzalez, Texas A&M Univ
Co-Author(s): C. McDonough, Texas A&M Univ; M. Riaz, Texas A&M Univ; L. Rooney, Texas A&M Univ

White food-type sorghum produces excellent foods. High-tannin (HT) sorghums will increase their antioxidant and dietary fiber contents. The objective was to evaluate the influence of genotype, milling methods (cracking, decortication, or intact grain), and tempering moisture (MC) on the performance of specialty sorghums in high-temperature short-time (HTST) extrusion. HT and waxy, heterowaxy and nonwaxy white sorghums were milled by the three methods and tempered to 14% MC. HT sorghum was also tempered to 13% MC. Extrudates of acceptable quality were produced from intact whole grains of all sorghum types tested. Interactions between MC and milling method of HT sorghum were observed for all variables measured except for bulk density (DEN). The best extrudates were obtained by tempering decorticated grain to 14% MC. These products had a DEN of 47.9 g/L, the highest expansion ratio (EXP = 4.4), and the lowest force to break in a Kramer press (FOR = 388 N). Specific mechanical energy (SME) was 503.9 KJ/Kg and feed rate (FR) was 180 Kg/h. Sensory texture was also the best among the HT treatments (good crunchiness, soft texture) and taste was slightly bitter. Interactions between genotype and milling method of the white sorghums were observed for all variables. The best extrudates were prepared by cracking the waxy grain. These products had a DEN of 93.9 g/L, an EXP of 3.5, and a FOR of 404 N. SME was 382.2 KJ/Kg and FR was 174 Kg/h. Sensory texture was very good and taste was bland. Milling of sorghum grains prior to extrusion enhanced the quality, but possibly decreased the nutraceutical value (less fiber and/or antioxidants) of the end-products as compared to those from intact whole-grains. Careful processing is needed to optimize both quality and nutraceutical value.

P-190
Soy-whey protein meat analog by high-moisture extrusion technology
Presenter: S. Adavalli, Department of Food Science, University of Missouri-Columbia, Columbia, MO
Co-Author(s): F. Hsieh, Department of Food Science, University of Missouri-Columbia, Columbia, MO; H. Huff, Department of Biological Engineering, University of Missouri-Columbia, Columbia, MO

A novel soy-whey protein based meat analog was prepared by high moisture extrusion technology using an APV Baker 50/25 intermeshing twin screw extruder with a 300 × 30 × 10 mm (L×W×H) cooling die. The effect of feed composition, barrel temperature, and moisture content on extruder responses (die pressure, torque, and product temperature) and the product properties such as product temperature, color, texture profile and the protein solubility were studied. The independent variables were feed composition, feed moisture (55, 60, and 65%), and barrel temperature (165°C, 170°C and 175°C). Four feed compositions were used by varying the percent ratios of soy protein isolate to whey protein isolate (60:0, 50:10, 40:20, and 30:30) and fixing vital wheat gluten and wheat starch at 35% and 5%, respectively. Thus, this was a 4× (3×3) split-plot factorial experimental design with two replications. The extruded products were immediately analyzed for their moisture and color. For texture profile analysis, samples were compressed to 50% of its original thickness by the TA.XT2 Texture Analyzer. The springiness, cohesiveness, hardness, and chewiness data were recorded. The protein solubility studies were carried out using various solvents including 0.035 M phosphate buffer, 1.5% sodium dodecyl sulfate (SDS), 0.1 M 2-Mercaptaethanol (2-Me), 8 M urea to determine the different chemical bonds responsible for the fiber formation. Bradford protein assay was used to estimate the amount of the soluble protein in each or combination of solvents. The optimum conditions of the extrusion process, the feed composition, and the moisture content were determined for the soy-whey protein meat analog which closely resembles the cooked chicken or turkey breast.

P-222 (((USER)))
Impact of frost damage on alkaline and white salted noodles
Presenter: D. Hatcher, Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB, Canada
Co-Author(s): J. Dexter, Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB, Canada; S. Symons, Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB, Canada

Frost damage has been shown to impact wheat milling characteristics and flour quality. It is a significant grading factor of Canadian wheat and this study was performed to assess its impact on Asian noodles. CWRS wheat samples (9) with equivalent protein content (12.6–13.0%), yet varying in their degree of visually assessed frost damage (No.1 through Feed), were milled to yield straight grade flours. A reduction in mill yield due to frost damage was detected on only the two most damaged samples. A significant decline in flour color was observed due increasing frost damage. Yellow alkaline (YA) and white salted (WS) noodles were prepared from each flour using a 1% w/w kansui (sodium and potassium carbonates 9:1) or NaCl solutions. Raw YA noodle brightness (L*) and redness (a*) of the severely frost samples were adversely affected at 2 and 24 hrs while yellowness (b*) displayed no effects. No consistent effect due to frost damage was observed on WS raw noodle color characteristics. A significant effect was observed in raw WS noodle speckiness due to the degree of frost damage but no effect was observed in YA noodles. Cooking water uptake was greater in WS than YA noodles but neither displayed an influence due to frost damage. WS noodles however did display a significant increase in solid loss due to increasing frost damage. No significant influence due to frost was observed on cooked noodle texture recovery, resistance to compression or maximum cutting stress in either type of noodle. However, those noodles displaying severe frost damage generally exhibited the poorest texture values.

P-226
Relationship of noodle characteristics with size exclusion HPLC chromatogram of wheat protein extract in soft white winter wheats
Presenter: A. Ross, Dept. of Crop & Soil Science, Oregon State Univ., Corvallis, OR
Co-Author(s): J. Ohm, Dept. of Crop & Soil Science, Oregon State Univ., Corvallis, OR; C. Peterson, Dept. of Crop & Soil Science, Oregon State Univ., Corvallis, OR

This research was performed to investigate relationship between molecular weight distribution of proteins extracted from whole meal of soft white winter wheats and oriental noodle quality. Molecular weight distributions of wheat proteins were analyzed by size exclusion (SE) HPLC. Absorbance area (AA) and area % (A%) of wheat proteins were compared with noodle characteristics. High molecular weight polymeric proteins (HMWPP) that eluted 12.5–13.1 min had significant (P < 0.05) positive correlations with noodle water absorption, hardness, chewiness, cohesiveness, and resilience. Protein fractions eluted from 15.3–20.1 min also had significant positive correlations with noodle hardness and chewiness. HMWPP had significant negative correlations with noodle sheet brightness (L*) and redness (a*) measured at 0 and 24 hr, and negative correlations with their respective differences between 0 and 24 hr. Protein fractions eluted from 14.5–19.6 had positive correlations with a* values at 0 (a*0) and 24 hr (a*24) and a negative correlation with delta a* between 0 and 24 hr. Area % for soluble protein fractions eluted from 21.4–22.2 min had significant negative correlations with noodle water absorption, hardness, cohesiveness, chewiness, and resilience. Protein fractions eluted from 21.4–22.2 min also had positive correlations with L* at 0 hr and delta a* but negative correlations with a*0 and a*24. Multivariate analysis techniques were applied to develop prediction models, using AA and A% of SE-HPLC. Prediction models for these soft wheats showed R(^2) values ranging from 0.902–0.756 for noodle water absorption, and textural and color characteristics. These results suggest that SE-HPLC of whole wheat protein could be used to evaluate noodle quality in soft winter wheats.

P-227 (((USER _ LIKELY)))
Relationships between cooked alkaline noodle texture and solvent retention capacity (SRC), SDS-sedimentation, mixograph, and protein composition
Presenter: O. Chung, USDA-ARS, Grain Marketing and Production Research Center, Hard Winter Wheat Quality Laboratory, Manhattan, KS
Co-Author(s): S. Park, USDA-ARS, Grain Marketing and Production Research Center, Hard Winter Wheat Quality Laboratory, Manhattan, KS; S. Bean, USDA-ARS, Grain Marketing and Production Research Center, Hard Winter Wheat Quality Laboratory, Manhattan, KS; S. Xiao, Kansas State University, Department of Grain Science and Industry, Manhattan, KS; T. Schober, Kansas State University, Department of Biological and Agricultural Engineering, Manhattan, KS

Due to increasing uses of hard winter wheat (HWW) in other than bread products, the Hard Winter Wheat Quality Lab included Asian alkaline noodle-making in the quality evaluation of the breeding program. Since the textural measurement of cooked noodle quality is too labor-intensive for thousands of breeding lines, we investigated relationships of texture profile analysis (TPA) values of cooked alkaline noodles of 34 HWW with quick tests generally used for bread quality estimation, i.e. SRC, SDS-sedimentation (Sed), computerized-mixograph (C-M), and protein content (PC) and composition. Some typical TPA values of cooked noodles included hardness, resilience, adhesiveness, and cohesiveness. The hardness values were negatively correlated with SDS-Sedimentation, 5% lactic acid (LA)-SRC, and insoluble polymeric protein content (IPP) (r = –0.53 to –0.75), and with PC (r = –0.38, n = 34, P < 0.05). Cohesiveness and resilience were positively correlated with SDS-Sed, 5% LA-SRC, and IPP (r = 0.61 to 0.74 and 0.46 to 0.72). Both flour PC and IPP were positively correlated with resilience and adhesiveness (r = 0.44 to 0.58). Of many C-M parameters, the height at 8 and 6 min values of C-M showed similar correlations, shown by SDS-Sed. Cooking loss was negatively correlated to resilience and cohesiveness (r = –0.78 and r = –0.80, respectively). Prediction equations were developed by stepwise multiple regression using PC and C-M parameters, resulting in R(^2) values of 0.67, 0.54, and 0.71 for cooked noodle hardness, resilience, and cohesiveness. The addition of SRC, SDS-Sed, and/or IPP data, the prediction improved the R(^2) from 0.54 to 0.62 for only resilience, but for others marginally, indicating the potential use of flour PC and CM-height values for predicting cooked noodle textures for the HWW breeding program.

P-234
Effect of nitrogen fertilization on protein composition, rheological properties, and baking performance of five experimental wheat lines
Presenter: A. Islas-Rubio, CIAD, A.C
Co-Author(s): K. Chavez-Quiroz, CIAD, A.C.; M. Granados-Nevarez, CIAD, A.C.; B. Silva-Espinoza, CIAD, A.C.; F. Vasquez-Lara, CIAD, A.C.; M. Camacho-Casas, CEVY-CIRNO-INIFAP, Ciudad Obregón, Sonora, Mexico

Wheat quality is determined by genetic and environmental factors. These factors affect protein content and composition; therefore gluten functionality. Nitrogen fertilization is an important management practice that influences the amount of protein accumulated in the grain. The aim of this work was to evaluate the effect of five nitrogen fertilization (NF) treatments on protein composition, rheological properties, and baking performance of five experimental bread wheat lines (BWL) grown at the Yaqui Valley Experimental Station in Sonora, México during the 2002–2003 growing cycle. Polymeric and monomeric proteins were evaluated by SE-HPLC. Dough rheological measurements were carried out with the National Mixograph and the texture analyzer TA-XT2 using the Kieffer extensibility rig. Baking performance was evaluated with a standardized baking procedure using the direct dough method. Different responses due to the NF treatments were observed among the BWL. In general, increasing the amount of urea favored protein content. The best NF treatments for most of the BWL were 300 kg of urea ha(^–1) either as one application at sowing (300-0-0) or three applications at three different stages of development (100-100-100). The dosage and timing of nitrogen fertilization can be manipulated to improve the baking quality of each EWL.

P-249
Rheological properties of Brazilian maize landrace flours
Presenter: N. Steinmacher, UFSC, Florianópolis, SC, Brazil
Co-Author(s): J. Raguzzoni, UFSC, Florianópolis, SC, Brazil; A. Alves, UFSC, Florianópolis, SC, Brazil; A. de Francisco, UFSC, Florianópolis, SC, Brazil; P. Rayas-Duarte, OSU, Stillwater, OK

The aim of this work was to evaluate the starch gelatinization and retrogradation of whole flour samples from eight Brazilian maize landraces. Their functional and thermal properties determined by RVA, texture analysis and rheology. For the dynamic properties the storage G(prime) and loss of energy G(double prime) modulus were obtained. The Rosado sample showed the major final RVA viscosity, but the major viscosity peak was that of Sol da manhã. All flours showed significant differences in their pasting properties. The RVA gels were used to perform the texture profile analysis. The gel firmness was determined using a compression force as a parameter to obtain an index of deformation. Gel texture is associated with syneresis and it represents the retrogradation level. The Roxo and MPA 13 landraces showed significant differences (P < 0.05). The highest retrogradation was obtained for MPA 13. The rheometer frequency sweep, applied in the viscoelastic properties determinations had low interference on the G(prime) and G(double prime) results and for all samples the G(prime) was higher than the G(double prime) modulus, allowing the classification of the formed gels as weak gels. The ratio of G(double prime) over G(prime) gives the tan delta value which can be associated to the material structure. The values found suggested that the gels had a polymer nature with vitreous crystallinity or gel. Since whole flour was used instead of isolated starch, the gels didn't have the formation of stable chains and strongly joined hydrogen bonds. The rheological results make easier future applications of the maize flours for starch-based products.

P-256
Effect of infra-red treatment on rice functionalities
Presenter: W. Chung, University of Arkansas, Fayetteville, AR
Co-Author(s): A. Han, University of Arkansas, Fayetteville, AR; J. Meullenet, University of Arkansas, Fayetteville, AR; D. Schluterman, University of Arkansas, Fayetteville, AR

Rice aging is a complex process observed in rough rice, brown rice, milled rice, and rice flour. Many physicochemical and physiological changes occur during rice storage. The most obvious indicators of the aging process in rice are the changes in pasting properties and cooked rice texture. The objectives of this study were to determine the effect of infra-red treatments on rice functionality, and to assess the potential of IR for accelerating aging of rice. Two rice cultivars (Bengal – medium grain, Francis – long grain) were harvested and divided into 4 aliquots. Three different levels of an Infra-Red (IR) treatment (i.e. end-temperatures of 60, 80, and 100°C) were used to induce changes in rice (IR-60, IR-80, and IR-100). One aliquot was used as a control sample (Non-IR). After IR treatment, each heated sample was tempered at the same temperature as the end-temperature of each IR treatment for 1 hr and then cooled down to ambient temperature. These rice samples then were stored at 21°C for 0, 3, 6, 9, and 12 wk. Head rice yield, pasting properties, and textural properties of cooked rice were assessed. The head rice yields for both Bengal and Francis decreased significantly due to the IR treatment (P < 0.001). IR-100 rice samples showed significant decreases in head rice yield after 9 wk of storage. According to the pasting viscograms, the pasting viscosities of both cultivars increased as the intensity of IR treatment increased. Hardness and stickiness of cooked rice of both cultivars were affected by the IR treatment. Hardness increased while stickiness decreased as the severity of the IR treatment measures. Overall, the trends tend to show that IR treated rice exhibit functional properties similar to those of aged rice. Therefore, IR treatment could be used as a tool to shorten the period of the conventional rice aging process. However, IR treatment conditions would need to be optimized to not negatively impact head rice yields.

P-268
Selecting pectins to reduce fat in passion-fruit pound cake
Presenter: Y. Chang, UNICAMP, Campinas, SP, Brazil
Co-Author(s): C. Steel, UNICAMP, Campinas, SP, Brazil; M. Belini, UNICAMP, Campinas, SP, Brazil

A high consumption of fat in the diets of a great part of the population has lead to a series of health problems, becoming a concern to governments, food manufacturers and consumers. One of the strategies to solve this problem is the introduction of low fat foods. In bakery products, the substitution of fat is a complex process, as in the production of biscuits, cakes and pies high levels of fat are normally used to obtain the desirable characteristics of tenderness and flavor. The ability of hydrocolloids to substitute fat has gained importance in the last few years. Pectins, polymers of polygalacturonic acid, are a type of hydrocolloid extracted from plants such as apples and citrus fruit. They are classified as high or low methoxyl content (HM or LM, respectively), amidated or not. These structural differences lead to differences in their applications and in their interactions with the other components of the food system where they are used. The general objective of this work was to use pectins to reduce fat in passion-fruit pound cake. The influence of different pectins (HM, LM and HM with alpha-amylase), at a 1.5% concentration, on the rheological properties of wheat flour was measured using the RVA (Rapid Visco Analyser). The different pectins were also tested in a reduced fat passion-fruit pound cake formulation. The quality of the cakes was evaluated by determining batter density, cake volume, subjective quality (sensory analysis test) and shelf-life (measuring moisture in a vacuum oven and hardness and gumminess using a TAXT2 Texture Analyzer, on days 1, 4 and 8 after production). From these evaluations the best reduced fat passion-fruit pound cake was chosen.

P-285
Development and characterization of edible films based on gelatin and waxy corn starches
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): F. Fakhouri, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; K. Watanabe, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; L. Mei, Department of Polymer Technology, Faculty of Chemical Engineering, State University of Campinas, Campinas-SP, Brazil

The development of edible films has been increasingly used in the past years as another environmentally friendly alternative for food packaging in substitution to synthetic materials. The use of different hydrocolloids in the preparation of edible films has the purpose of combining the positive aspects of each component. The objective of this work was the development of edible films using waxy corn starch (native and modified) and gelatin in the proportions of 1:4, 1:1 and 4:1 as well as the characterization of the obtained films in terms of permeability to water, solubility in water, solubility in acid and mechanical properties (tensile strength and elongation percent at break). For all the films, glycerol was used as a plasticizer. The addition of gelatin resulted in an increase of the thickness of the films for all proportions, made up to 39% for native and 45% for modified corn starch films. In those films with modified corn starch, the addition of gelatin also resulted in 29% increase of the tensile strength and for native corn starch this increase was approximately 14%. In general, the films made with modified corn starch presented higher water solubility. For the film made with 4:1 proportion, the lowest value of water vapour permeability was observed. All the films were completely soluble in acid and there was no difference on elongation at break. The films were transparent and flexible and their barrier properties show their potential to be used in several food applications.

P-286
Effect of amylose/amylopectin ratio and gluten on retrogradation properties of wheat starch gels
Presenter: K. Matkovic, Department of Plant Sciences, North Dakota State University, Fargo, ND
Co-Author(s): M. Chakraborty, Department of Plant Sciences, North Dakota State University, Fargo, ND; L. Grant, USDA-ARS, Fargo, ND

Starch interacts with other flour components in a complex system like bread. Therefore, it can be expected that retrogradation properties of starch will be affected not only by its structural properties, but also by the presence of other flour polymers like gluten. Gel model systems were used to investigate the effect of amylose/amylopectin ratio, and the effect of starch and gluten interaction on the retrogradation of starch. A normal non-waxy wheat starch was blended with 0, 12.5, and 25% waxy tetraploid wheat starch, in presence and absence of gluten (70:30 ratio), and gelatinized using a Rapid Visco Analyzer (RVA). Gels were stored at 4°C for 20 days and analyzed after 0, 5, 10, 15 and 20 days. Textural and thermal properties of gels were analyzed using TAXT2i texture analyzer and differential scanning calorimeter, respectively. Non-waxy starch gels exhibited significant increase in firmness after five days of storage, whereas firmness of gels made with 12.5 and 25% waxy starch had slower rate of firmness increase. Starch-gluten gels had significantly lower firmness values that pure starch gels. This difference was especially pronounced in the control (non-waxy starch) gel sample. Higher amount of waxy starch in blends resulted in higher values for enthalpy of gelatinization, with starch-gluten gels having lower enthalpies than their corresponding starch blends. Starch-gluten gels also exhibited smaller increase in enthalpy of retrogradation during storage than their corresponding starch gels. Soluble starch from gels was extracted with water and analyzed by gel permeation chromatography. Two distinct peaks were obtained; however, the samples differed in the amount of different starch fractions and their composition.

P-290
Effect of starch granule size on the thermal and rheological properties of maize
Presenter: J. Figueroa, CINVESTAV Unidad Querétaro, Querétaro, Qro., Mexico
Co-Author(s): E. Narváez González, Universidad Autónoma de Querétaro, Querétaro, Qro., Mexico; J. Velés Medina, CINVESTAV Unidad Querétaro, Querétaro, Qro., Mexico; M. Gaytán, CINVESTAV Unidad Querétaro, Querétaro, Qro., Mexico; S. Taba, CIMMyT, El Batán, Texcoco, México C.P.

Maize (Zea mays L.) is the most important cereal in the Latin American diet and it is also the most versatile, due to the large quantity of products that can be made from this grain. The kernel is mainly composed of starch and its size varies among different races. Studying the gelatinization process provides us with important information about the functionality, energy requirements, and end use of this cereal. The aim of this work was to determine the relationship between starch granule size and the thermal and rheological properties of 71 pure corn races from Latin America. SEM and optical microscopy were used to obtain micrographs from soft and hard endosperm samples. DSC was used to determine the gelatinization temperatures and enthalpies. Viscoamylograph curves were obtained using an RVA. Protein, moisture, fat, amylose, and ash content as well as kernel hardness were also determined. It was found that small starch granules gelatinize slowly and have higher temperature and enthalpy values. Starch granule size was also found to have some relationship to kernel hardness. Soft grains had larger starch granules in soft endosperm, and smaller ones in hard endosperm. The opposite was found to be the case in hard grains. Hardness was also found to be correlated to temperature, range, and enthalpy of gelatinization. Starch granule size was inversely correlated to time and temperature for peak viscosity. Finally, it was determined that starch granule size is proportional to the moisture and amylose content and inversely correlated to protein content in soft endosperm samples, while in those with a hard endosperm a direct relationship between size and protein content and an inverse relationship between size and fat content were observed.

P-295
Improving texture of cold maize starch gels by adding guar and xanthan gums
Presenter: F. Collares, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil
Co-Author(s): F. Weber, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil; Y. Chang, Department of Food Technology, Faculty of Food Engineering, State University of Campinas, Campinas-SP, Brazil

In this work, guar and xanthan gums were evaluated as agents against the negative effects of cold storage on the texture of normal, waxy and high amylose maize starch gels. Maize starch gels containing the gums (0.15; 0.50; 0.85 and 1%), with a total solids content of 10%, were prepared. The gels were analyzed with respect to firmness after storage for 7 days at 10°C. The results showed that for the normal (M) and high amylose (AM) maize starch gels, stored under refrigeration for 7 days, the addition of xanthan gum improved the texture and minimized the effects of retrogradation at the concentrations used. It was also observed that the AM gels were more rigid than the others and that the addition of xanthan gum at the minimum concentration used (0.15%) reduced their force significantly. This gum also improved the texture of waxy maize (AP) starch gels, but to a lesser degree, due to the lower trend to retrograde of this starch. The gels of M and AP starches with added guar gum presented variations in the values of force during storage. It was observed that the minimum concentration necessary for this gum to be effective against retrogradation was 0.85%. There were no modifications in the texture of the gels prepared with high amylose (AM) starch and guar gum during storage. A significant reduction in gel firmness was only verified for the fresh gel (time 0) with the addition of 1% guar gum.

P-302
Sorption isotherms for starch polyol systems and the use of models to predict behaviour
Presenter: S. Hill, University of Nottingham
Co-Author(s): J. Enrione, University of Nottingham, UK; I. Farhat, University of Nottingham, UK

Many starchy systems utilise polyols to maintain flexibility. This investigation used three cereal starches, waxy maize, wheat and rice, thermomechanically extruded in the presence of four different levels of glycerol (0, 5, 10 and 20%) to evaluate how these samples would hydrate and to assess their T(g). Moisture uptake was measured after equilibrium at different relative humidities (RH) using Dynamic Vapour Sorption equipment. The level of glycerol had a marked effect on the moisture levels within the samples. Glycerol increased water contents at high humidities, but suppressed moisture uptake at low RH values. From the resultant isotherms the monolayer coverage for all the samples were calculated using the GAB model. With 20% glycerol the values (6.5%) obtained were less than in the starches without polyol (9%) for all the starches tested. Diffusion coefficients for the samples were also calculated assuming Fickian diffusion. Values increased as the samples hydrated, but the models were deemed inappropriate at a particular water content. This point correlated to the T(g) of the sample and observation showed that at higher moistures the samples collapsed and the assumptions of spherical shaped particles was no longer appropriate. T(g) values were measured by differential scanning calorimetry and by dynamic mechanical thermal analysis. These data were compared to values obtained from a multi-component model based on the DCp and T(g) contribution of each component of the mixture (modified Couchman-Karazs eq). Good correlation between the methods occurred at low levels of polyol, but when the amount of glycerol increased the model no longer predicted behaviour. It was thought that phase separation occurred in these samples.

P-304
Variability in starch from selected corn hybrids and its effect on food functional properties
Presenter: L. Cabrales, Univ of Illinois, Urbana, IL
Co-Author(s): T. Rocheford, Univ of Illinois, Urbana, IL; Y. Niu, Univ of Illinois, Urbana, IL; S. Eckhoff, Univ of Illinois, Urbana, IL

Pasting properties of starch are important in food processing and have been used to predict starch cooking characteristics and food textural properties. Variability in pasting properties of starch has been demonstrated. What is not known is the impact starch pasting property variability has on processing economic or food characteristics. The objective of this research was to determine the effect of variability in starch pasting properties from diverse hybrids on the cooking and textural properties of pudding. Corn hybrids grown at the same location with a common parent line were laboratory wet milled using 100g procedure. The resulting starch pasting properties were determined through RVA analysis. Starch final viscosities of the 87 corn hybrids evaluated varied from 1706 cP to 2225 cP. The control starch, normal yellow dent corn starch obtained from a commercial wet miller, had a final viscosity of 1897 cP. It has been suggested from industry contacts that a 5% increase in final viscosity of the starch pasting properties would be the best predictor of a practical difference among pudding characteristics. Seven hybrids were selected based on a 5% increase in final viscosity to further test for pudding cooking (RVA) and textural properties (texture analysis). There was a significant difference among the starch pasting properties of the selected hybrids. There were significant differences in the pasting, and textural properties among the pudding samples. There can be a formula reduction of over 10% starch for specific hybrids to obtain the same food textural properties as the control starch.

P-307
Barley tortillas: Relationship between composition, instrumental and sensory texture measurements
Presenter: N. Ames, Agriculture & Agri-Food Canada, Winnipeg, MB, Canada
Co-Author(s): C. Rhymer, Agriculture & Agri-Food Canada, Winnipeg, MB, Canada; D. Ryland, Agriculture & Agri-Food Canada, Winnipeg, MB, Canada

Tortillas with acceptable texture containing nutritional benefits of increased total dietary fibre (TDF) and beta-glucan (BG) have potential in the marketplace. Understanding the relationship between the textural perception of barley tortillas, instrumental measurements and fibre components will aid in the development of tortillas made from non-traditional flour sources. Flour from fifteen barley cultivars representing a range of starch characteristics was blended to 60% extraction using straight grade flour, dusted flour from bran and dusted flour from shorts. Tortillas were evaluated by a sensory panel trained to measure the intensity of seven textural attributes on a 15-cm line scale. A 1.9-cm diameter probe attached to the texture analyzer was directed downward through the centre of the tortilla to the break point. Slope of the instrumental texture curve showed a significant correlation with all seven of the sensory textural attributes as well as the BG and starch level. A decrease in slope produced higher rollability, ease of compression and stickiness to teeth. An increase in slope produced higher breakability, hardness, chewiness and moisture absorption. Time to break the tortilla resulted in significant correlations for five of the seven attributes, peak force two attributes, and area produced no significant correlations. As BG and TDF increased hardness and chewiness decreased. Chewiness was significantly lower for samples with a higher level of BG when measured on tortillas made from three cultivars with bran added. It would appear that the slope is the most useful measurement to relate to tortilla textural perception. This relationship was implemented to assess the suitability of tortillas made from barley flours with different composition.

P-308
Corn tortillas high in antioxidants and dietary fiber developed with bran from specialty sorghums
Presenter: G. Cedillo, Texas A&M University
Co-Author(s): A. de Castro Palomino, Texas A&M University; R. Waniska, Texas A&M University; L. Rooney, Texas A&M University

Some specialty sorghums have high phytochemical content. Corn tortillas enriched with sorghum bran would be rich in antioxidants and dietary fiber and are an excellent vehicle for nutraceutical delivery due to widespread and growing consumption. The objective was to evaluate the effects of sorghum bran addition on corn tortilla properties, antioxidant activity, and sensory characteristics. Interaction of sorghum bran and an antistaling formula containing guar gum, carboxymethylcellulose and maltogenic alpha-amylase was also studied. Tortillas containing 0, 5, and 10% bran from sumac (high tannin) and black (high in anthocyanins) sorghums, with and without the antistaling formula, were prepared from nixtamalized corn flour. Tortilla texture after storage for four days at refrigeration was measured by objective and subjective tests. Tortillas were analyzed for phenols (Folin-Ciocalteu) and antioxidant potential (2,2(prime)-azinobis (3-ethylbenzothiazoline-6-sulfonic acid). Tortillas with the antistaling formula and 5% sorghum bran were evaluated on a nine point hedonic scale for appearance, aroma, texture, and flavor. Tortillas containing sorghum bran had a more friable structure than the control, which was overcome by the antistaling formula. Levels of phenols and antioxidant activity increased with increasing bran addition. One serving of 5% sumac bran tortilla qualifies as a "good source of fiber" and had an antioxidant activity equivalent to that of 50 g of blueberries (fresh wt.). Tortillas containing sorghum bran were acceptable to panelists. At 5% sorghum bran inclusion, there was no significant difference in sensory attributes from the control aside from appearance. The sorghum bran gives the product a dark color, a characteristic associated with many healthy foods.

P-309
Effect of emulsifiers on textural properties of whole wheat tortillas
Presenter: H. Akdogan, USDA-ARS-GMPRC, Manhattan, KS
Co-Author(s): O. Chung, USDA-ARS-GMPRC, Manhattan, KS

100% whole wheat (WW) products offer many health benefits by being naturally rich in fiber and bran as well as in B and E vitamins, iron, phytochemicals, and phytoestrogens. 100% WW tortillas have their own sizable market and like other tortilla types their shelf-life and texture play vital importance in consumer acceptance. The literature on 100% WW tortillas is scarce, therefore, this study was performed to evaluate the influence of three different types of emulsifying agents, sodium stearyl lactylate (SSL), lecithin, and glyceryl monostearate (GMS), on tortilla staling. All samples were subjected to extensibility (tear) tests by using a TA-XT2 Texture Analyzer at days 0, 2, 4, 8, 12, 16, and 20 days of storage. A completely randomized statistical design was chosen. One-way analysis of variance (ANOVA) was used to analyze the data. There was not a significant difference among the means of color attributes of tortillas (L, a, b) as well as the means of tortilla diameters. The maximum force to tear and gradient (modulus of deformation) were highly correlated to tortilla rollability scores (a scale of 0 to 5 was used, 5 being the most acceptable). Although all emulsifiers improved the shelf-life, lecithin at 2% resulted in the lowest maximum force to tear at day 0 (softest) as well as the highest rollability score (3.5/5) at the end of day 20. The control tortillas were the most stretchable (longest distance to tear) at day 0 compared with the tortillas made with emulsifiers. However, at day 20, the control and emulsifier added tortillas did not exhibit a significant difference regarding the distance to tear. Among all three emulsifiers used, lecithin at 2% level was the most effective to improve the shelf-life and texture of 100% WW tortillas.

P-311
Effect of traditional nixtamalization and instant masa flour production on starch characteristics and tortilla properties
Presenter: R. Yglesias, Department of Food Science and Technology, University of Nebraska, Lincoln, NE
Co-Author(s): D. Jackson, Department of Food Science and Technology, University of Nebraska, Lincoln, NE

To better understand the impact of specific unit operations on starch properties, starch attributes were characterized at various points during traditional nixtamalization, instant masa flour production, baking and storage. Alkaline cooking and baking increased water absorption index (WAI) as seen by greater values in nixtamal as compared to raw corn, and in tortillas as compared to their masas. Water solubility index (WSI) decreased due to alkaline cooking and nixtamal steeping. Rapid Visco-analyzer (RVA) peak, setback and final viscosities increased when corn was exposed to non-thermal moist unit operations such as steeping and rehydration, but decreased during thermal processing steps such as, coarse ground masa dehydration and baking. The baking process had the most impact on X-ray diffraction patterns and differential scanning calorimeter responses. Tortilla rollability and flexibility decreased during storage, but at a greater rate for instant masa flour products. No differences among tortilla masa types were observed for WAI, although WAI consistently decreased 30 min after baking. Tortilla WSI decreased with storage time, and fresh masa tortillas had higher WSI values than tortillas made with instant masa flour. RVA viscosities were higher in fresh masa than in instant masa tortillas (P < 0.09). No masa type or time differences were found in DSC parameters, but retrogradation enthalpy increased during storage. Differences in starch solubility, thermal and pasting properties as well as variations in tortilla quality could be explained by agglomeration of starch granules during dehydration of coarse ground masa.

P-315
Nixtamalized flours from fraction of dry-milling of corn (Zea mays L.): Optimization of alkaline processing
Presenter: J. Milan-Carrillo, Univ of Illinois
Co-Author(s): C. Edith, University of Illinois and Universidad Autónoma de Sinaloa; R. Cuauhtémoc, Universidad Autónoma de Sinaloa; C. Lynda, University of Illinois; E. Steven, University of Illinois

Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa, tortillas, flours, snacks). Processors adjust nixtamalization variables based on experience. The objective of this work was to know the best combination of nixtamalization process variables for producing nixtamalized dry milling fractions (corn grits & corn meal) flours for use In making tortilla. The nixtamalization conditions were selected from factorial combinations of process variables: For corn grits & corn meal were (nixtamalization time (NT, 8–22 min) and cooking temperature (CT, 78–88°C). Lime concentration and flour/cooking ratio were 1% (w/v) and 1:4, respectively. A central composite experimental design with five variation levels was chosen. Response surface methodology (RSM) was applied as optimization technique, over four response variables: Texture of the masa [hardness (MH) and adhesiveness (MA)] and tortilla [rupture force (TRF) and extensibility force (TEF)]. Predictive models for response variables developed as a function of process variables. The Conventional graphical method was applied to obtain similar MH, MA, TRF and TEF to control (MASECA). Contour plots of each of the response variables were utilized applying superposition surface methodology, to obtain contour plot for observation and selection of best combination of nixtamalization process for production of nixtamalized flour of fractions of dry milling (corn grits & corn meal). The best combinations to corn grits were: Nixtamalization time (NT, 18 min); cooking temperature (CT, 83°C) and corn meal were: Nixtamalization time (NT, 15 min); cooking temperature (CT, 83°C).

P-316
Tortilla-making characteristics of nixtamalized flours from fraction of dry-milling of corn (Zea mays L)
Presenter: E. Cuevas-Rodriguez, University of Illinois and Universidad Autónoma de Sinaloa
Co-Author(s): J. Milan-Carrillo, Univ of Illinois and Universidad Autónoma de Sinaloa; C. Reyes-Moreno, Universidad Autónoma de Sinaloa; C. Campabadal, University of Illinois; S. Eckhoff, University of Illinois

The effects of the traditional nixtamalization process on texture profile analysis and RVA pasting curves made in masa and tortilla of two nixtamalized flour of fraction of dry milling corn (corn grits & corn meal) were evaluated. The masa of corn meal had higher (P less than equal to 0.05) hardness (1.131 vs. 0.828), adhesiveness (0.027 vs. 0.011), cohesiveness (0.436 vs. 0.218), Springiness (0.503 vs. 0.216), gumminess (0.496 vs. 0.173) and chewiness (0.259 vs. 0.037) than masa of control (Maseca). However, masa of corn grits and control (Maseca) did not show significant changes. The cutting force of tortillas of corn grits and corn meal did not show significant differences. The highest values of tensile strength of tortillas were found for the control (Maseca) followed by corn meal and corn grits. The viscoamylograph peak viscosities, setback and final viscosity decreased drastically from masa to tortillas in corn grits, corn meal and control (Maseca). Tortillas from corn grits and corn meal showed good characteristic of texture, puffing and consistency of masa.

P-317
Zero trans-fat tortillas
Presenter: F. Bejosano, Texas A&M University
Co-Author(s): J. Alviola, Texas A&M University; R. Waniska, Texas A&M University

Declaring the amount of trans fat on food labels may affect consumer's choice of foods, due to growing health concerns. Most tortillas are made with hydrogenated shortening containing 12–30% trans fats. Solid fats with 0–4% trans fat can be made without hydrogenation through fractionation, interesterification, or blending of saturated and polyunsaturated oils. Polyunsaturated oils have low levels of trans fats, are liquid at room temperature but may not have the desired functionality of hydrogenated shortenings. The objective of this study is to determine the effects of replacing hydrogenated shortening with non-hydrogenated fats that have no or minimal amounts of trans fats on tortilla quality. Soybean oil, palm oil, fractionated palm oil-based shortening and interesterified shortening at 12% level were evaluated during processing and on tortilla qualities. The tortilla bake test was used to prepare tortillas. Tortillas containing fractionated palm or interesterified shortenings (solid fats) had opacities, diameters and textural attributes similar to tortillas prepared using trans-fat shortening. Tortillas containing soybean oil or regular palm oil (fats with lower melting index) required less time to mix and yielded tortillas with lower opacities. The proper selection of fats low in trans fats yielded tortillas that could be labeled zero grams trans fat per serving.

4
The role of proteins in the determination of rice functionality. J.-F. MEULLENET. Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704.

Because of the increasing use of rice in the food industry, there is a need for rice processors to pay close attention to rice quality, including functional characteristics including cooking, texture and pasting properties. This presentation will give an overview of what is known about the role of proteins in the determination of rice functionality as well as current research undertaken by the UofA Rice Processing Program. Milled rice contains approximately 75–80% starch and 6–9% protein. Starch is a mixture of amylose and amylopectin, and variation in amylose content has significant effects on cooking and eating qualities of rice. As a general rule, higher amylose rice cooks harder and its flour is less viscous. However, it appears that the prediction of texture or other functional characteristics from starch properties alone has become insufficient since rice with similar starch structure sometimes exhibits very different functional characteristics. Protein is an important part of the rice endosperm not only because it is the second most abundant component, but also because of its ability to bind with starch and affect the pasting properties of rice flour and the texture of cooked rice. Although rice proteins are thought to influence rice functionality (such as texture) their precise role has not been established. A number of studies have shown the relationship between protein content and texture. Primo et al. (1962) reported that rice with a higher protein content was, in general, firmer. Juliano et al. (1965) demonstrated that increased protein content within a cultivar resulted in firmer cooked rice. Hamaker and Griffin (1990, 1993) proposed that rice starch granules bound proteins restricted the swelling of the granule during cooking, influencing the texture of the final product. The various rice proteins present in rice (i.e. albumin, globulin, prolamin and glutelin) can undergo changes such as protein cross-linking, protein-carbohydrate interactions, and protein denaturation during rice post-harvest processing. Teo et al. (2000) reported that the modification of the protein component, rather than the starch, was primarily responsible for rheological changes associated with aging of rice flour. Furthermore, Chrastil (1990) reported that the number of disulphide bonds and the average molecular weight of oryzenin (a rice protein) increased significantly during storage of rice grains. Associated with such changes were decreases in protein solubility and reversible binding of oryzenin to starch molecules. Teo et al. (2000) concluded that as starch-oryzenin interaction decreases during aging, its influence on paste viscosity considerably lessens, thereby allowing the predominant starch fraction to more fully exert its effects on rheological properties. This could explain why rice flour pastes increase in viscosity as rice storage duration increases. Current studies are focusing on functional field variability of long-grain rice. Results show that rice harvested from a single rice field can be quite variable in functional properties. This is interesting because environmental conditions and cultural practices in a single field should be similar. This implies that even small changes in water or nutrient availability can have a significant impact on rice quality. We also established that functional characteristics can be predicted from both starch and protein chemistry. This is not necessarily a new finding, since many studies have demonstrated the role of starch and to some extent proteins in determining functional characteristics such as cooked rice texture. However, this study illustrates the fact that the same general principles apply to variations in functionality within a single cultivar. In addition, the study raised questions about the roles of specific starch and protein fractions in determining rice functionality. Proteins were found to be as important in determining rice texture and pasting properties as starch. Although some progress has been made toward understanding the role of proteins in determining rice functionality, much work remains to be done on understanding the interaction between proteins and starch fractions.

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Protein fractions of wheat flours and their relationships with noodle quality. X.Z. HU. College of Food Science & Engineering, Northwest Sci-Tech University of Agriculture & Forestry, Yangling, Shaanxi, 712100, China.

The protein fractions of 25 Chinese wheat varieties were studied with a new protein extracting method, and also the relationships between protein fractions and other protein indexes, dough property, and fresh noodle quality. The average proportion of monomeric protein, soluble glutenin and insoluble glutenin of Chinese Huanghuai winter wheat zone is 3.7:1.0:1.8. Compared with the Canadian wheat variety, the monomeric protein is lower, the soluble glutenin content is higher and the insoluble protein is lower. The insoluble glutenin is highly significantly related to Zeleny sedimentation volume and extensibility energy of extensograph, significantly related to SDS sedimentation and maximum resistance of extensograph. The soluble glutenin is correlated only with Zeleny sedimentation value and extensibility length of extensograph. The monomeric protein is significantly positively correlated with fresh noodle maximum resistance of extension, extension distance and extension area. The soluble and insoluble glutenin content are significantly correlated with fresh noodle maximum resistance of extension, extension distance, extension area and fresh noodle thickness using a texture analyzer, but is negatively related with fresh noodle sheet length. The results suggested that the soluble glutenin content has the most functionality for noodle special flour, and the soluble glutenin content can be used for the Chinese noodle special wheat screening in the early generation.

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Variability assessment of rice milling quality and texture of cooked rice. R.C. BAUTISTA, W.K. Chung, T.J. Siebenmorgen, and J.-F. Meullenet. Department of Food Science, University of Arkansas, Fayetteville.

Understanding milling quality attributes and cooking properties of rice is important in the determination of suitable end-use processing and commercial valuation of milled rice and its by-products. The goal of this study was to determine variability in rice quality as affected by cultivar, planting region, and in-field location. Four long-grain rice cultivars (Cocodrie, Drew, Lemont and Wells) grown in various locations in Arkansas and Mississippi were evaluated for head rice yield, milled rice milling attributes and cooked rice texture. Statistical analysis indicated that head rice yield (hry) and milling degree attributes (whiteness, transparency and degree of milling) were affected by cultivar and planting location. Correlations were also established between head rice yield and milling degree attributes with hry inversely related to whiteness and degree of milling while transparency was directly related to hry. Texture of cooked rice was determined according to hardness and stickiness. Hardness and stickiness of cooked rice was different among cultivars and planting location. Variability effects of cultivar and planting location on milled rice quality and texture of cooked rice were determined. Information derived from this study will benefit the rice industry in terms of commercial valuation of milled rice and determination of suitable processing strategy for a desired end-use product.

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Suitability of Canada's new hard white wheat class for Asian noodles: An environmental study. D.W. HATCHER (1), O.M. Lukow (2), J.E. Dexter (1), F. Townley-Smith (2), and M.J. Anderson (1). (1) Grain Research Laboratory, Canadian Grain Commission, 1404-303 Main St., Winnipeg, MB R3C 3G8, Canada; (2) Agriculture and Agri-Foods Canada, 195 Dafoe Rd., Winnipeg, MB R3T 2N2, Canada.

The new Canadian wheat class, Canada Western Hard White (CWHW) was evaluated for its suitability in the Asian noodle market. The samples included two standard Canada Western Red Spring (CWRS) varieties and three hard white spring varieties, grown in duplicate plots at three locations over three years. Flours (60% patent) were used to make yellow alkaline noodles (YAN) which were tested for various noodle quality attributes. Color analysis, measured using a HunterLab LabScan, indicated all noodles prepared from the CWHW varieties displayed superior brightness (L*) and lower redness (a*) than Barrie, the current dominant CWRS variety, at all times after noodle preparation. Texture of cooked noodles was evaluated using a TA-TX2 Texture Analyzer. Bite (MCS) was consistently superior to Barrie for one of the CWHW varieties while results were mixed for the other two varieties. Other texture characteristics, including TPA parameters, showed that the texture of the CWHW wheats produced noodles of equivalent or superior quality to Barrie. Image analysis of all CWHW cultivars displayed superior appearance to Barrie. CWHW offers noodles with superior color and appearance while simultaneously retaining the strong texture characteristics provided by CWRS.

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Breadmaking quality of durum wheat: Effects of semolina particle size, fermentation time and glutenin molecular size. P. DAVID (1), H.D. Sapirstein (1), J.E. Dexter (2), and K.R. Preston (2). (1) University of Manitoba, Department of Food Science, Winnipeg, MB R3T 2N2, Canada; (2) Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB R3C 3G8.

The increasing popularity of durum wheat bread makes identifying factors associated with improved baking performance desirable. We examined the effects of glutenin composition, semolina granularity and varying fermentation time on bread loaf volume (LV) and crumb texture of North American and Italian durum wheats. Wheat was milled into granulars (G, semolina and flour combined) of 75% extraction. G particle size was further reduced by sizing rolls to increase starch damage to a level similar to that of common wheat flour. Baking was by the Remix-to-Peak procedure at initial fermentation times of 15, 90 and 165 min. There were large genotypic differences in dough rheological properties and LV that were strongly related to insoluble glutenin content of cultivar samples. Reduced G had significantly increased Farinograph absorption, dough mixing requirements, but not baking absorption or LV. Increasing fermentation time negatively affected breadmaking performance; on average LV decreased 13%, baking absorption decreased 6%, and crumb firmness increased 38%. Using unreduced granulars and short fermentation benefits the breadmaking quality of durum wheat. Of even greater importance is selecting the right genotypes, i.e. those with high content of large polymeric glutenin.

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Characterization of dry pea extrudates with added fiber by scanning electron microscopy (SEM) and texture analyzer. M. CHENG (1), J.D. Berrios (2), M.J. Garnanez (3), J. Tang (1), and B.G. Swanson (3). (1) Washington State University, Dept. Bio. Sys. Eng., Pullman, WA 99164; (2) USDA-ARS-WRRC, Albany, CA 94710; (3) Washington State University, Dept. Food Sci., Pullman, WA 99164.

Characterization of selected food attributes is of value in formulation and development of new products. The objective of this research was to investigate the effect of added fiber on the microstructure and textural characteristics of dry pea extrudates. SEM was used to evaluate extrudate microstructure. The stress-strain curve was measured by a texture analyzer which characterizes the crunchiness of the extrudate. Dry pea flours with two different fiber sources, apple pomace fiber (APF) and wheat bran (WB), at concentrations of 5, 10, 15, or 20% were extruded at a die temperature of 160°C and 15% moisture (wb). Fiber addition decreased cell size but did not significantly change cell wall thickness. The area under stress-strain curve, as the energy needed to crash the extrudates, increased significantly (P < 0.05) with fiber concentration. Equivalent amounts of APF increase more crashing energy than WB. Microstructural and textural attributes of food extrudates are important information that can be used in development of extruded snack foods.

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Low-temperature extrusion manufacturing of Asian-style noodles. J.C. MORALES (1), J.L. Brent (2), and C. Deyoe (3). (1) Frito-Lay, Inc., Plano, TX 75024; (2) The Iams Co., Lewisburg, OH 45338; (3) Kansas State University, Manhattan, KS 66506.

The objective of this study was to examine low-temperature forming extrusion for Asian-style noodle manufacturing as compared to roll-machine noodle making. Pasting, cooking, color, and textural characteristics of Asian style noodles prepared with Kansas Oro Blanco and Idaho 377s white wheat flours using low-temperature forming extrusion were examined. The effects of two different die land lengths on noodle cooking quality were also evaluated. The characteristics of low-temperature extruded noodles was compared to those manufactured using the roll-machine method (Ohtake noodle machine). Significant differences in cooking loss, pasting properties, texture and color were found between low-temperature extruded noodles and roll-machine noodles. Extruded noodles showed higher cooking loss than noodles made by the roll-machine method. On the other hand, roll-machine noodles were harder, firmer and more adhesive. In addition, roll-machine noodles showed larger L* (lightness), lower a* (green), and lower b* (yellow) in the L*a*b* color space than low-temperature extrusion forming. Low temperature extruded noodles made with die inserts differing in land length did not show significant differences in any of the attributes examined.

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Effect of wheat-koji on baking quality of bread. M. OTANI (1,2), R. Mujoo (2), and P.K.W. Ng (2). (1) Nitto Flour Milling Company Ltd., Tokyo, Japan; (2) Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824.

Chemical agents are commonly used as dough conditioners to overcome deficiencies in the breadmaking quality of wheat gluten. However, recent studies questioning safety have led to a focus on natural ingredients. Koji is a natural ingredient that is rich in enzymes, including amylases and proteases, and other functional ingredients beneficial for health. It is made by fermenting cereal with koji mold (Aspergillus oryzae) and is used in the processing of Japanese sake, miso and soy sauce. Wheat-koji (WK) has been developed (Japanese patent P2000-300159A) and is widely available in Japan and sold as a commercial product in fresh or dried form. This study explored the effect of incorporating WK on the quality of breads made from non-frozen and frozen doughs. Use of transglutaminase (TG) and WK in improving bread quality was also investigated. Dough samples were prepared from commercial wheat flour (control), with two levels of WK (0.05 and 0.1%), and in combination with WK and TG (0, 0.05, 0.1, 0.2%); samples of each dough type were frozen (0, 1, 3, 6, 12 weeks) prior to analysis of bread quality. No difference in loaf volumes was observed between bread baked from dough samples without and with WK. However, greater improvement in loaf volumes was seen when WK and TG were added together than with TG alone, suggesting that WK and TG work synergistically to improve the quality of bread.

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French bread baked from wheat flours of reduced starch amylose content. C.S. PARK, B. Paszczynska, and B.-K. Baik. Washington State University, Department of Food Science & Human Nutrition and IMPACT, Pullman, WA 99164-6376.

The potential uses of wheat flours, of reduced starch amylose content, to improve shelf life of pan bread has been explored and verified for the reduction in crumb firmness during storage. Waxy and partial waxy wheat flours were used to determine their potential uses in making French bread of extended shelf life and the influence of starch amylose content on crumb firmness of bread during storage. Starch amylose content was about 25% in regular wheat, 21% in single null partial waxy, 16% in double null partial waxy and 1.8% in waxy wheat flours. Loaf volume of bread ranged from 577 to 603 mL in regular wheat, 507 to 597 mL in partial waxy and 490 to 520 mL in waxy wheat flours. Crumb moisture content of bread at 48 hr after baking was similar among regular and partial waxy wheat flours (33.2-35.7%), but much higher in waxy wheat flours (>38.9%). Crumb firmness of bread stored for 48 hr was < 8.6 N in double null partial waxy, 10.6 N in single null partial waxy and > 11.3 N in regular wheat flours. Partial waxy wheat flours exhibited generally lower DSC enthalpy values of starch retrogradation in bread at 24 hr after baking, but higher enthalpy at 48 hr after baking than regular wheat flours. Partial waxy wheat flours impart desirable characteristics for making French bread with extended shelf life.

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Effect of micronization on the cooking quality and fiber characteristics of partially pearled barley. N. AMES (1), C. Rhymer (1), B. Rossnagel (2), and S. Arntfield (3). (1) Cereal Research Centre, Agriculture & Agri-Food Canada, Winnipeg, MB; (2) University of Saskatchewan, Saskatoon, SK; (3) University of Manitoba, Winnipeg, MB.

Barley can provide consumers with a good source of dietary fiber, beta-glucan and antioxidants, but the lack of developed end products for barley prohibits its regular consumption in the average diet. Micronization, an infrared heat process which exposes material to electromagnetic radiation in the wavelength range of 1.8 to 3.4 microns, offers potential for improving the application of barley for human food. This study investigated the effect of micronization on the cooking quality, functional properties and fiber characteristics of barley pearled for 30 sec or 1 min following treatment. Micronization was effective in lowering the cooking time required to achieve an acceptable texture. The effect of this treatment was also demonstrated in the pasting properties of the ground material; RVA peak, hot paste and final viscosities of 30-sec and 1-min pearled material were increased with micronization. Pasting properties were also affected by the moisture content of the grain during micronization. Micronization increased the beta-glucan acid extract viscosity for both the 30-sec and 1-min pearled samples above 16% moisture, suggesting potential enhancement of nutritional quality.

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Properties of instant whole grain barley products created by infrared heat treatment. N. AMES (1), C. Rhymer (1), B. Rossnagel (2), and S. Arntfield (3). (1) Cereal Research Centre, Agriculture & Agri-Food Canada, Winnipeg, MB; (2) University of Saskatchewan, Saskatoon, SK; (3) University of Manitoba, Winnipeg, MB.

Barley can provide consumers with a good source of dietary fiber, beta-glucan and antioxidants, but the lack of developed end products for barley prohibits its regular consumption in the average diet. Micronization, an infrared heat process which exposes material to electromagnetic radiation in the wavelength range of 1.8 to 3.4 microns, offers potential for modifying the properties of barley to create a whole grain barley that can be used as an instant-cook side dish or as a snack food. This study investigated the effect of grain moisture level and genotype on the physio-chemical properties of micronized barley resulting from processing in a pilot-scale infrared heating system under specific conditions. Compared to an untreated control, barley that was subjected to infrared heat exhibited increased kernel water absorption capacities as well as increased RVA peak, hot paste and final viscosities. Barley beta-glucan content remained stable after micronization but its acid extract viscosity was 10 to 15 times higher than the control. Micronization also resulted in the inactivation of peroxidase enzymes in the barley. The functionality of the micronized barley was also affected by heat/moisture treatment and genotype.

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Maternal background influence on wheat grain texture. K.R. GEDYE (1), C.F. Morris (2), A.D. Bettge (2), and M.J. Freston (2). (1) Department of Food Science and Human Nutrition, Washington State University, Pullman, WA 99164-6376; (2) USDA-ARS Western Wheat Quality Laboratory, Pullman, WA 99164-6394.

Grain texture is an important characteristic for both the milling and end use quality of wheat. Mutations in either of the two puroindoline genes (pinA or pinB) account for the majority of variation (ca. (r = 0.7) in grain texture. However, other factors, yet to be fully elucidated, also influence grain texture. One of these factors is the textural response due to the mutated puroindolines in different maternal backgrounds. To investigate the response of the puroindoline genes, a population of 228 F(7) recombinant inbred lines from a cross between the two hard wheat cultivars Klasic (pinB-1b) and ID377S (pinA-1b) were analyzed using the single-kernel characterization system and genotyped for their puroindoline genes. Analysis of variance of the hardness scores using maternal parent and puroindoline mutation as blocking factors, identified a significant (P < 0.001) interaction between the maternal background and the puroindoline mutation. Lines containing the pinA-1b mutation were, on average, harder than lines containing the pinB-1b mutation. However, Klasic lines containing the puroindoline mutations were significantly harder than ID377S lines also containing the same mutation. These results indicate that interactions among other genetic factors which influence grain hardness and the wild type puroindolines are more pronounced in Klasic than in ID377S.

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Alkaline-carbonate noodles made from hard winter wheats with varying amylose levels. L. F. ZHAO and P. A. Seib. Dept. of Grain Science and Industry, Kansas State University, Manhattan, KS 66506.

The effects of wheat starch and protein on Asian salt noodles have been studied extensively. Increased swelling power of flour correlates highly with the preferred soft but elastic texture of the cooked salt noodle. The objective of this study was to determine the effect of starch swelling on the texture (instrumental) of cooked alkaline noodles made from 15 flours milled from three-wheat varieties, Lakin, Ike and 2137, grown in 1999 and 2000. The protein levels, hot-water swelling powers (SP95) and total starch contents in those flours (69% extraction), respectively, ranged from 8.4-12.9%, 16.7-24.1 g/g and 78.2-82.5%. The partial-waxy Ike flours gave an elevated SP95 of 21.5-24.1 g/g, but the non-waxy Lakin and 2137 gave SP95 of 16.7-18.9 g/g. The cooked noodles made from Lakin and 2137 showed 30-50% lower tensile strength at break than those from Ike flours, while their compression strength (50% strain) was 10-20% higher. Those results imply that alkaline noodles made from a partial-waxy wheat has a more tender bite, but a more stretchy and tacky texture than those from wild-type wheats. The low-protein hard wheats, as shown by previous investigation, gave somewhat brighter noodles compared to the high-protein wheats.

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Influences of starch amylose content of wheat on processing and textural properties of instant fried noodles. B.-K. BAIK, B. Paszczynska, and C.S. Park. Washington State University, Department of Food Science & Human Nutrition and IMPACT, Pullman, WA 99164-6376.

Starch amylose content has considerable effects on the quality of wheat-based food products. Reduced starch amylose content, as in partial-waxy wheat, improves the textural properties of white salted noodles, while little is known about effects of starch amylose content on processing and quality of instant fried noodles. Instant fried noodles were prepared from reconstituted flours of various amylose content (3.0-26.5%) with or without steaming and evaluated for oil absorption and texture of cooked noodles. Instant fried noodles of <12.4% starch amylose exhibited numerous surface bubbles and would stick together during frying, which could be alleviated by frying noodles without pre-steaming. Omitting steaming process led to higher fat absorption, thicker strands and longer cooking time of fried noodles. As starch amylose content increased from 3.0 to 26.5%, water absorption for making noodles decreased from 49 to 39%; fat absorption decreased from 35.8 to 23.3; hardness of cooked noodles increased from 1.39 to 3.57; and cohesiveness of cooked noodles decreased from 0.70 to 0.65.

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Relationships between protein characteristics of wheat and quality parameters of instant fried noodles. C.S. PARK and B.-K. Baik. Washington State University, Department of Food Science & Human Nutrition and IMPACT, Pullman, WA 99164-6376.

Instant fried noodles are in large demand and comprise the major uses of wheat flour in many Asian countries, though flour characteristics appropriate for making instant fried noodles necessitate further investigation. Fourteen flours of hard and soft wheat and three commercial flours for making noodles were used to determine the relationships between flour protein characteristics and quality parameters of instant noodles. Protein content of flours ranged from 8.2 to 12.2% in soft wheat, 10.9 to 17.5% in hard wheat and 10.1 to 10.8% in commercial flours. Hard wheat and commercial flours exhibited longer mixing time and lower proportion of salt-soluble protein than soft wheat flours. Water absorption for making noodles related negatively with flour protein content and ranged from 34 to 37% in soft wheat and commercial flours and from 31 to 35% in hard wheat flours. Soft wheat flours generally produced more yellow color of dough and fried noodles than hard wheat and commercial flours. Both protein content and protein quality parameters were significantly correlated with oil absorption and yellowness of uncooked noodles, and textural parameters of cooked noodles. Free fat content of fried noodles exhibited negative correlations with brightness and hardness of cooked noodles.

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Wheat quality for Northern-style Chinese steamed bread. H. ZHANG, C.E. Walker, and X. S. Sun. Kansas State University, Dept. of Grain Science & Industry, Manhattan, KS 66506.

Steamed bread is popular in China and other Asian countries. Flour, water, and yeast (or sourdough starter plus soda) are its basic ingredients. It is characterized by a relatively dense crumb and thin white skin rather than having a very spongy crumb and brown crust. The flour requirements and the optimum processing parameters are poorly defined. An American soft wheat at three protein levels, two Kansas hard red winter wheats at five protein levels, and two Kansas hard white winter wheats at three protein levels were compared with a standard Chinese wheat for making Chinese northern-style steamed bread. Wheats were Buhler milled to straight grade flours. Steamed bread quality was evaluated for specific volume, subjective quality score, skin and crumb color, and texture profile. Steamed bread specific volume was positively correlated with protein content for all wheat samples. However, strong dough strength caused post-baking collapse and an unsatisfactory surface appearance (winkles and blisters). High quality products were obtained when Kansas hard wheat flour was blended with Chinese wheat flour or American soft wheat flour at ratios varying from 75:25 to 50:50. Steamed bread made from hard white wheat had a much brighter skin color than that made from red wheats. Protein quantity and quality are critical in steamed baking. Kansas hard white wheat with moderate protein content and dough strength has superior steamed bread baking quality.

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Effect of genetic modifications at Gli-2 loci on the flour characteristics and functionality. M.R. PIROZI (1), F. MacRitchie (2), and D. Kasarda (3). (1) Federal University of Vicosa, Dept. of Food Technology, Vicosa, MG, Brazil, 36571-000; (2) KSU Dept. of Grain Science and Industry, Manhattan, KS 66506; (3) U.S. Department of Agriculture, Agricultural Research Service, Albany, CA 94710.

The wheat variety Chinese Spring is recognized for its weak breadmaking properties. In the present study, the 6A chromosome of Chinese Spring was substituted by the 6A chromosome of Cheyenne, a wheat variety with stronger mixing properties. Modified Chinese Spring, nullisomic at 6A, 6D and tetrasomic at 6A, 6B, or 6D were also used. The objective was to investigate the effect of gliadins encoded at the Gli-A2, Gli-B2, and Gli-D2 loci on the protein composition and dough properties. Protein content was determined by nitrogen combustion (LECO), and protein composition was measured by SE-HPLC. Mixograph and TA-XT2 were used to determine the rheological properties of the dough. A baking test was performed to verify the overall quality of the flours. Compared to the parent flour Chinese Spring, the protein content and proportion of monomeric protein (SE-HPLC peak 2 area) distinctly varied with modification and substitution of 6A/6B chromosomes. Results suggest a possible effect on the polymeric protein content (peak 1 area) and in the unextractable proteins percent. These alterations may explain the results observed for dough rheological properties. In a general conclusion, the absence of gliadins from 6A was not compensated by the proteins from the extra 6B chromosome. Such modification produced stickier doughs, with significantly higher extensibility, lower resistance to extension, weaker mixing properties, and poorer baking performance than the parent line. The substitution of the 6A chromosome from Cheyenne seems to improve the dough rheological properties, particularly the resistance to extension of the flour, but the effect is not as sharp as those observed for the modified line.

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Relationship between alpha-amylase activity and functionalities of rice during rough rice storage. W.K. CHUNG, A. Han, and J.-F. Meullenet. University of Arkansas, Food Science, Fayetteville, AR 72704.

Starch is a mixture of amylose and amylopectin, and variation in amylose content has significant effects on rice quality. Alpha-amylase catalyzes the hydrolysis of amylose, yielding a mixture of maltose and glucose. Thus, changes in alpha-amylase activity during rough rice storage could affect the functionality of rice. The objective of this study was to assess the changes in alpha-amylase activity during storage and its effects on rice functional properties. Rice samples (cv. Bengal, Cocodrie, Cypress, and Francis) were harvested in the fall of 2002 and stored at 12% moisture content and 21°C for a period of 36 weeks. Alpha-amylase activity was determined on brown rice flour as a concentration of maltose. Pasting properties were measured using a rapid visco-analyzer (RVA 4, Newport Scientific) and cooked rice texture using a compression test performed using a Texture Analyzer (TAXT2i, Texture Technologies, Scarsdale, NY). Alpha-amylase activity in rice was highest during the first 8 weeks of storage and then decreased. Peak viscosity of rice was highly positively correlated with alpha-amylase activity (P < 0.01). Alpha-amylase activity was negatively correlated with hardness (P < 0.001), while it was positively correlated with stickiness of cooked rice (P < 0.001). These results suggest that the assessment of alpha-amylase activity in rice may be helpful in predicting rice functionality and cooked rice quality.

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Properties of chemically modified waxy durum wheat starches. M. CHAKRABORTY, L.R. Berglund, and K. Matkovic. Cereal and Food Sciences, NDSU, Fargo, ND 58105.

The physical and functional properties of hydroxypropylated (HP), cross-linked (XL), and dual-modified (HP-XL and XL-HP) waxy durum wheat starches were compared with waxy untreated control starch (WX), with the objective of broadening their applications in the food industry. SEM micrographs did not reveal any morphological changes due to the modifications; however, significant differences among treatments were seen in x-ray diffraction, DSC and RVA parameters. DSC enthalpy (J/g) and % relative crystallinity of XL starch were similar to WX, whereas HP, HP-XL, and XL-HP starches displayed lower values, indicating changes in crystalline structure. Similarly, the DSC gelatinization temperatures were statistically similar for WX and XL, and significantly lower in HP, HP-XL, and XL-HP starches. HP starch displayed a slight increase in RVA peak viscosity (PV) followed by a rapid breakdown, whereas, XL starch displayed the highest resistance to breakdown among all the treatments. HP-XL and XL-HP showed similar PV values, but HP-XL displayed comparatively lower breakdown and higher setback values. Gels formed in the RVA were analyzed for firmness after 24 h, and 20 days of refrigerated storage. The rate of change in gel firmness with time was highest in WX (7 g vs. 30 g), moderate in XL (33 g vs. 41 g) and lowest in HP starch (5 g vs. 7 g). HP starch formed a clear, stringy paste that did not gel irrespective of the storage time, whereas, XL formed the most firm and opaque gel upon storage. HP-XL and XL-HP starches formed softer gels compared to XL, and retrograded at a slower rate during refrigerated storage.

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Influence of hydrocolloids in bread technology quality. M. Munhoz de Michel (1,2) and Y. KIL CHANG (2). (1) Rhodia Food, Paulinia (SP), Brazil; (2) Department of Food Technology, Food Engenieering Faculty, UNICAMP.

The baking industry has an economic interest in increasing bread shelf-life and improving its sensory characteristics. The main objective of this work was to present the influence of hydrocolloid combinations on the technological quality of bread. Hydrocolloids influence gelatinization and the retrogradation starch process, affecting the dough rheological behavior and bread staling. A surface response methodology was used to evaluate the results and to determine the optimum formulation for bread, including 11 combinations of the independent variables: xanthan gum (0.0-1.0 parts) and guar gum (0.0-1.0 parts). The dough properties measured for each combination were: water absorption, development and stability time, deformation energy of dough and curve configuration ratio and viscosity (RVA). The bread quality attributes determined were: yield, specific volume, water activity (aw), moisture content, instrumental texture using TA-XT2 texturometer and sensory evaluation using a nine-point structured scale. Xanthan gum showed a greater influence on the specific volume than guar gum. The best result in terms of texture were observed with a combination of a lower dosage xanthan gum (0,15%) and higher dosage of guar gum (0,85%).

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Influence of freezing conditions on the baking quality of frozen bread dough. M. Salas-Mellado and Y. KIL CHANG. Departamento de Tecnologia de Alimentos, FEA/UNICAMP, Cidade universitária, Barão Geraldo, Campinas, CP: 6121 Cep: 13084-971, SP, Brazil.

Nowadays in Brazil frozen dough is an attractive technology for the baking industry. For this reason, conventional mechanical refrigeration (blast tunnel) was compared with a cryogenic system. Yeasted dough cylinders were frozen under controlled conditions to determine the influence of air temperature, air velocity and dough piece weight on the quality and stability of the dough after freezing and frozen storage. The basic formulation (flour based) was: flour (100%), water (farinographic absorption less than 2%), instant dried biological yeast (1.3%), salt (2%), sugar (2%), hydrogenated vegetable fat (2%), sorbitan monooleate (0.3%), ascorbic acid (120 ppm), vital gluten (4%) and D+ trehalose (10%, based on the yeast dry weight). The effects of the variables studied were evaluated both in the dough, from the rheological characteristics (TAXT2 texturometer), viable yeast count and CO2 volume released (rheofermentometer) and in the bread, from the specific volume, crumb hardness and technological score. A statistical analysis of the data after 50 days of frozen storage for the dough frozen in the cryogenic freezer, showed that a temperature of -30°C was better than -50°C and a dough piece of 175 g performed better than a piece of 80 g. A statistical analysis of the data after 60 days of frozen storage for the dough frozen in a blast tunnel, showed that a temperature range of -20 to -25°C, an air velocity range of 4.2 to 5.14 m/s and a dough piece weight range of from 80 to 120 g were the better conditions for stability and quality of the dough and bread.

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Development of instantaneous pasta using two different types of wheat and cooking-extrusion process: The influence of raw materials on the quality of the product. M. Depieri and Y.K. CHANG. Departamento de Tecnologia de Alimentos/FEA/UNICAMP. Cidade Universitária, Zeferino Vaz, Campinas, SP, Brazil.

In order to guarantee a better quality of pastas, semolina of durum wheat (T. durum) is considered the more indicated raw material. On the other hand, it presents a high cost, when compared with flours of other wheat varieties. This work analyzed the production of instantaneous pasta using two types of raw materials, flour of common wheat (T. aestivum) and semolina of durum wheat (T. durum), and thermoplastic extrusion process. A single-screw extruder was used, following a rotatable central-composite design with 3 independent variables: the temperature in the 2nd zone of the extruder (x(1)), moisture of initial mixture (x(2)) and rate of emulsifier in the initial mixture (x(3)). The analyzed answers were: cooking time, cooking loss and texture, including maximum force of rupture and work of rupture. High quality obtained pastas presented cooking time of 1.5-2.0 minutes, minimum cooking loss (1.5%), force of 15-20 g and work of rupture around 50 g.s. In the case of durum wheat semolina, the conditions of process to get such characteristics were 115°C, 26% of initial moisture and 1,0% of emulsifier. Using common wheat flour, the process conditions included temperature of 105-110°C, moisture 24-25% and high percentage of emulsifier (1.15-1.5%). The work showed that it is possible to obtain products with similar qualities, using two distinct types of raw materials.

304
Evaluation of extrusion properties of quality protein maize and high protein corn. A. LEAL-DIAZ (1), L. Rooney (1), R. Waniska (1), M. Barron (2), and M. Riaz (2). (1) Cereal Quality Laboratory, Texas A&M University, 2474 TAMUS, College Station TX 77843-2476; (2) Food Protein Research and Development Center, Texas A&M University, 2476 TAMUS, College Station, TX 77843-2476.

Extrusion properties of quality protein maize (QPM) and high protein corn (HPC) were compared to commercial white corn (CWC). QPM has twice the amino acids lysine and tryptophane, while HPC has higher protein content, both compared to regular corn. New improved QPM and HPC have good agronomic and yield performance. All samples were compared for thousand kernel weight, test weight, hardness, density, and protein, lysine and tryptophan content. To prepare samples, whole grain and decorticated (10 percent) were coarsely hammer milled, sifted (sieves US No. 25 and US No. 40) and equilibrated to 12-13 percent moisture. The extruder was a high-temperature, high-shear, single screw short barrel extruder (Madox). Extrudates were baked at 115 degrees Celcius and evaluated. QPM grain and extrudates had significantly greater amounts of lysine and tryptophan compared to CWC and HPC. Extrudates made of coarser particle size from decorticated grain had higher expansion ratio and lower bulk density for all samples. Extrudates from HPC required the highest force to break followed by QPM and CWC. It is feasible to extrude QPM and HPC with excellent characteristics. Extrudates made from QPM and HPC would have significantly improved nutritional value.

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Factors affecting extrusion of white sorghum to produce whole grain snacks. D. ACOSTA (1), M. Barron (2), M. Riaz (2), R.D. Waniska (1), and L.W. Rooney (1). (1) Cereal Quality Lab., Soil & Crop Sci. Dept., Texas A&M Univ., College Station, TX 77843-2474; (2) Food Protein R&D Center, Texas A&M Univ., College Station, TX 77843-2476.

Processing conditions were optimized to produce direct-expanded extrudates with superior characteristics from whole white sorghums. Whole sorghum extrusion provides the nutritional benefits of whole grains, saves energy, and avoids dry matter losses. 11, 12, 13 and 14% moisture whole sorghums were extruded in a dry single-screw extruder. Yellow cornmeal as control, and white sorghums with waxy, heterowaxy and hard endosperms were utilized, all of which had significantly different extrusion properties. Factors affecting the extrusion properties included moisture, use of emulsifier and die configuration. Reduction from 6 to 4 die holes increased expansion for all treatments by increasing retention time and mechanical energy application. The extrudates made from sorghums at 12% moisture and 0.5% emulsifier were homogeneous, highly expanded and were preferred in a sensory evaluation using baked, flavored products. Extrudates made from waxy and heterowaxy sorghums were more expanded and had crisper texture. In general, whole white sorghum extrudates were whiter, less expanded, bland flavored, and had similar texture to those made from cornmeal. Whole white sorghum was extruded satisfactorily, producing extrudates with excellent expansion and crunchy texture that was accepted by consumers.

307
Modifications in proteins upon extrusion of QPM grits and implications on extrudate texture. M.C.D. PAES (1), B.B. Hamaker (2), M.B. Stone (3), and J.W. Lawton (4). (1) Embrapa Maize and Sorghum, Sete Lagoas, MG, Brazil, 35701-970; (2) Dept. of Food Science, Purdue University, West Lafayette, IN; (3) Dept. of Food Science and Nutrition, CSU, Fort Collins, CO; (4) NCAUR-ARS-USDA, Peoria, IL.

Although zeins have been shown to positively influence texture in corn-based extrudates, differences in distribution of zein fractions as observed in Quality Protein Maize (QPM) have not been evaluated to date. This research was aimed to study the effect of high gamma-zein content in QPM on modifications of maize proteins during extrusion and determine their implication on extrudate texture. Proteins in normal and QPM maize grits extruded at various levels of shear (SME 50, 75, 160, 250, 320, and 430 kJ/kg) were extracted using either urea, SDS, SDS+urea, and SDS+urea+2-ME containing buffers, and submitted to quantification and separation using the BCA assay and SDS-PAGE. Texture was determined using the Warner-Bratzler test. Maize proteins undergone chemical and structural modifications during extrusion driven by noncovalent and covalent interactions. Disulfide bonding was apparently more important for QPM samples. Extrudates produced with QPM grits were more brittle than normal corn extrudates (P < 0.05), perhaps due to the high gamma-zein content. The use of QPM grits in the production of extruded corn-based products may result in extended bowl-life of corn flakes and enhanced crispness of expanded snacks.

309
The effects of a rice based glycolipid emulsifier on extruded corn meal. M.E. BARRON (1), C.M. McDonough (1), M.N. Riaz (2), and L.W. Rooney (2). (1) Food Protien R&D Center-Texas A&M University; (2) Cereal Quality Lab-Texas A&M University College Station, TX 77843.

Commercial de-germed corn meals with and without 0.5% of a rice based glycolipid emulsifier were extruded using a single screw high temperature-high shear baking extruder (Maddox Metal Inc.). Particle size distribution and moisture content were determined of the corn meal. The physical, textural, and microstructure difference of the two samples were compared. The corn meal was tempered to 14% moisture before extruding. The extrudates were typically 3 cm long and 1.5 cm in diameter. The extrudates containing 0.5% of the glycolipid emulsifier had a lower bulk density. Viewed with environmental scanning electron microscopy, the extrudates without the emulsifier had thicker cell wall junctions, which contributed to a tougher texture. The extrudates with emulsifier had more evenly distributed air cells that were of a more consistent size and shape with thinner air cell walls. The emulsifier may be improving the flow characteristics of the starchy continuous phase, allowing a more even distribution of air cells and air cells walls. Using a Texture Analyzer TA-XT2, the extrudates with emulsifier were tenderer and had lighter structures. The use of the rice based glycolipid emulsifier decreases bulk density, distributes air cells in the extrudates more evenly and contributed to a more tender texture in the collet.

310
Effect of variety and environment on cooking quality, physical and pasting characteristics of field peas (Pisum sativum). N. WANG, J.K. Daun, and D.W. Hatcher. Canadian Grain Commission, Grain Research Laboratory, 1404-303 Main Street, Winnipeg Canada R3C 3G8.

Cooking time and texture are important quality attributes of field peas for human consumption. Factors that affect cooking quality of field peas include cultivar, seed characteristics, location and environment. The objectives of this study were to study the effect of variety and environment on cooking quality, physical and pasting characteristics of field peas and to determine the relationship between cooking quality and physical and pasting characteristics. Protein content within a variety was used as an indicator of environmental effect. Four field pea varieties, each with three levels of protein content, were selected. Cooking time was determined with the Mattson cooking device. Hardness of cooked peas was measured with a TA-HDi texture analyzer. Pasting characteristics of the ground pea flour was measured using a Rapid Visco Analyzer (RVA) (AACC method). Analysis of variance showed that both variety and environment had a significant effect on cooking time, 100 seed weight, and hardness of cooked seeds, but hydration capacity was only affected by environment. A positive correlation was found between seed weight and water hydration capacity. Cooking time correlated negatively with water hydration capacity. Hardness of cooked peas was negatively correlated with both seed weight and water hydration capacity, but positively related with cooking time. The relationship between cooking quality and pasting characteristics was also examined in this study.

314
New oats technology for breadmaking. L. BASINSKIENE (1), G. Juodeikiene (1), R. Bernatoviciute (1), and H. Salovaara (2). (1) Kaunas University of Technology, Lithuania; (2) University of Helsinki, Finland.

Non-heat-treated oat groats have essential benefits (i.e., bioactivity) in breadmaking compared with cooked groats. However, the texture of these products is unacceptable because of groats dryness and hardness. Therefore non-heat-treated oat groats require special treatment to soften them. The object of our investigation was to develop an effective method of softening non-heat-treated groats and to select the optimal supplementation of groats for mixed bread processing. Different methods for groats softening by hydration were tested during the experiment. The treatment - rinsing groats twice with 95°C water, then soaking in 30°C water - allowed to reduce groats hardness more than 10 times in 30 min and to prevent the microbial growth on oats. This groats treatment was used for the processing of mixed bread (wheat/oat). The effect on bread quality of oats supplementation for 25, 50 and 75 percent of wheat flour was studied. The texture of bread with 50 percent groats was of acceptable quality and valuable from the nutrional point of view. Experiment showed that the quality of mixed bread could be improved using multienzyme composition, containing xylanase, glucoamylase and alpha-amylase. The new oats technology developed allows to use non-heat-treated groats in baking. Therefore, beta-glucan and other oat components have saved the natural state in baked products and could be claimed as healthy food.

315
Effect of dough crumb and sheet resting on noodle processing and quality characteristics. B.X. FU, E. Assefaw, and L. Malcolmson. Canadian International Grains Institute, 1000-303 Main Street, Winnipeg, Manitoba, Canada R3C 3G7.

The development of the gluten matrix during dough mixing and sheeting is a critical factor in determining noodle processing characteristics and eating quality. It is well documented that resting has a significant impact on the physical properties of the dough during processing. This study was carried out to examine the effects of resting the dough crumb after mixing and the dough sheet after sheeting on noodle processing characteristics and end quality. Fresh white salted noodles and yellow alkaline noodles were made from flour milled from Canada Western Red Spring wheat. Dough crumbs were rested for 0, 30, and 60 min before sheeting, and processing into noodle strands without sheet resting. Noodle sheets, made from un-rested dough crumbs, were rested for 0, 30, and 60 min after the second compounding pass. For both resting methods, sheeting properties, dough sheet color, and cooked noodle texture were evaluated. Sheet resting significantly changed the noodle sheeting properties. After sheet resting, the resulting noodle sheets were thinner and less work was required to sheet the dough at the same passes with fixed gap settings. The surface of the noodle sheets was also smoother and showed an improvement in hydration after sheet resting. The impact of crumb resting on sheeting properties was not significant. For both resting methods, there was no significant difference in noodle sheet appearance and cooked noodle texture 24 hours after noodles were processed. The significance of these findings in relation to commercial noodle production is discussed.

325
Optimization of instrumental compression texture analysis of cooked rice. A. HAN, W.K. Chung, J.A. Hankins, and J.-F. Meullenet. University of Arkansas, Food Science, Fayetteville, AR 72704.

Developing an effective instrumental method to measure the texture properties of cooked rice has become essential as the texture is important for rice quality. The objective of this study was to evaluate various compression methods for cooked rice texture and correlations with sensory perception of texture attributes. Four rice cultivars were evaluated for texture properties by sensory and instrumental means. The cooked rice texture was measured with a double compression test using a 90% strain (Test I), and a single compression test using a distance gap of 0.3mm (Test II). Both tests were performed on samples cooked in 10-g aliquots. A compression test similar to Test I (Test III) was performed on rice cooked for sensory evaluation (i.e., 300-g aliquots). Instrumental tests were performed by a Texture Analyzer. Hardness by Test III was correlated with sensory hardness for Bengal and Cypress (r(^2) = 0.92 and 0.97). Stickiness by Test I was correlated with sensory stickiness for Francis, Cypress, and Cocodrie (r(^2) = 0.64, 0.85 and 0.70, respectively). Stickiness by Test II was highly correlated with sensory stickiness for Bengal and Cocodrie (r(^2) = 0.81 and 0.79). The results suggest that instrumental tests for cooked rice can be useful in predicting major sensory attributes of cooked rice. However, instrumental results seem to be cultivar dependent and kernel size should be taken into account if multiple cultivars are to be compared.

337
Development of a micro-scale procedure to prepare wheat flour tortillas. S. ARORA (1), R. Lyne (2), J.N. Alviola (1), G. Lookhart (2), R.D. Waniska (1), and O.K. Chung (2). (1) Soil & Crop Sci., TAMU, College Station, TX 77843; (2) USDA-ARS, GMPRC, Manhattan KS 66502.

Processing parameters for a micro-procedure were established to produce wheat flour tortillas. Two laboratories were involved in optimizing a heated, hand-press (DP2000, Dough-Pro) and griddle parameters to produce tortillas comparable with those produced by pilot-scale Lawrence equipment. Press conditions of 55-105C, 3-10 sec, and 5-12 kg weight, attached to the handle were evaluated. Griddle conditions of 150- 250C and 30-120 sec were evaluated. Tortillas were evaluated for opacity, diameter, thickness, shelf stability and textural properties. Fourteen flours were prepared into dough (42 g) and tortillas using both types of equipment. Good quality tortillas have large diameter, high opacity, and long shelf-stability. Processing parameters for the Dough-Pro and the griddle were established that yielded tortillas with properties similar to those made using pilot-scale equipment. Processing conditions of the Dough-Pro were 74C, 7 sec, 12 kg, and "thin"; setting with the griddle at 160+5 C for 80 sec. Under these conditions, tortilla diameter and opacity scores positively correlated to results from the Lawrence equipment. Similar trends were observed among the two laboratories. This micro-procedure can be utilized when sample amount is limited, such as early-generation variety testing, and/or pilot-scale equipment is unavailable.

340
Effect of high moisture content stored maize grain on tortilla quality. J.A. Méndez-Albores (1), G. ARÁMBULA-VILLA (1), and E. Moreno-Martínez (2). (1) CINVESTAV-IPN. Libramiento Norponiente # 2000 Fracc. Real de Juriquilla, Querétaro C.P. 76230, México; (2) FES-Cuautitlan. UNAM. Cuautitlán Izcalli, Mexico.

Maize Zea mays L. is the primary staple food of the Mexican population; maize grain is used mainly in the preparation of tortillas and other derivatives. In Mexico, the maize grain is often handled with high moisture content (MC) (16 to 20% dwb) as a result of a lack of grain drying facilities, along with high relative humidity specifically in tropical areas and poor storage conditions, which affect the quality of grain and finally the quality of the tortillas produced. Therefore, the quality of nixtamalized maize is also affected by the quality characteristics of the maize grain. In this work, maize grain with MC of 18% was stored during 10, 15 and 20d at 28°C. A control grain lot was stored 20d at 4°C with a low MC 10.7%. The traditional nixtamalization process to make tortillas was used. The growth of storage toxigenic fungi in maize grain and the parameters for quality of the tortillas produced were evaluated. The statistical analysis showed significant quality differences between tortillas made with maize with high MC and those made with grain of low MC (Dunnet 0.05). High moisture content of the grain had a significant effect on tortilla quality parameters such as pH, tortilla color, tensile strength, cut force, viscosity peak, starch retrogradation and aflatoxin contamination. In general, the inadequate storage conditions of the grain caused poor quality characteristics in the tortillas produced.

341
Improved diameter and shelf stability of flour tortillas by added wheat proteins. S. PASCUT (1), J. Garza (2), L. Silva (2), and R.D. Waniska (2). (1) Urys Foods, Miami, FL; (2) Cereal Quality Lab., Dept. Soil & Crop Sci., Texas A&M Univ, College Station, TX.

Several commercial wheat proteins were evaluated in wheat flour tortillas to determine their effects in low-protein-strength flours. Wheat protein fractions were evaluated at 0.25-7.0% usage levels. Oxidants were also evaluated in combination with low levels of wheat protein fractions. Tortillas were prepared using laboratory-scale, commercial equipment with fixed processing parameters. Dough and tortilla properties were stored in plastic bags at 22C for 28 days. Shelf stability of tortillas prepared from low-protein-strength flours improved using 1% of several protein fractions. Addition of oxidants (10-20 ppm) with or without wheat protein fractions improved tortilla shelf stability with no chage in diameter or opacity. Tortilla shelf stability was improved without loss of other tortill

342
The impact of ingredient formulation on wheat flour tortilla stickiness. G. GUO and D.S. Jackson. Dept. of Food Science & Technology, University of Nebraska-Lincoln.

A reduced ability to individually separate packaged tortillas (a.k.a. tortilla stickiness) is a highly undesirable trait, especially for the food service industry. In addition to wheat flour quality and tortilla processing conditions, ingredients used during tortilla manufacturing influence stickiness. Central composite response surface methodology (RSM) designs were employed in this study. Increasing amounts of both baking powder (from 0 to 2%) and shortening (from 0 to10%) greatly (P < 0.0001) reduced tortilla stickiness, while the impact of flour falling number (200-400 seconds, adjusted by adding malt) was not significant. The level of baking power addition was critical because it also influenced other tortilla characteristics (P < 0.01), such as diameter, thickness, opacity and color. Tortilla stickiness was also impacted by reducing agent use, gum type and gum addition levels.

343
The role of beta-glucans, enzymes and CMC in tenderizing corn tortillas. A.C. GUTIERREZ DE VELASCO, L. Silva, L.W. Rooney, and R.D. Waniska. Cereal Quality Lab, Soil and Crop Sci. Dept., Texas A&M Univ., College Station, TX 77843-2474.

The effects of beta-glucan and its interaction with other additives were evaluated on the texture and flavor of fresh and stored corn tortillas. Dry masa flours with three levels of beta-glucan (0.25, 0.5 and 1%) from two sources (70% beta-glucan extract and barley flour with 10% beta-glucan) were prepared into tortillas. Flavor of fresh tortillas and texture of tortillas over storage (7 days) were evaluated. Combinations of beta-glucan (0.25%) with 0.25 CMC or 550 MAU of alpha-amylase were also evaluated. No off-odors or off-flavors were detected in all tortillas containing beta-glucan extract. Tortillas containing barley flour (0.5 or 1% beta-glucan) had a milder corn flavor and a slight barley flavor. Increasingly firm textures of all tortillas were observed. The tortillas that contained as low as 0.25% beta-glucan retained a softer texture during storage. When beta-glucans were used along with CMC, an improvement in texture was also observed but not with alpha-amylase. Beta-glucans retard the staling of tortillas and could be used in combination with other additives.

346
Improvement of whole rice bread. R.S. KADAN. Southern Regional Research Center, ARS.USDA, 1100 Robert E. Lee Blvd, New Orleans, LA 70124.

Rice grain has many unique attributes such as ease of digestion, bland taste, hypoallergenic properties and the absence of gliadin protein moiety. In addition, the rice bran (RB) components are reported to lower cholesterol and blood sugar. Rice flour, along with RB, is therefore an ideal food ingredient to make whole rice bread (WRB) for people suffering from celiac sprue and other chronic diseases. Absence of gliadin (and hence gluten) and the addition of RB, however, offer special challenges to make a yeast leavened WRB as the carbon dioxide formed during baking is not retained. The presently available rice breads require the addition of potato, tapioca and other starches to make a satisfactory bread which can unnecessarily increase the chances of objectionable contamination of gluten in the final product. We have developed a WRB using commonly available rice flours, RB, rice bran oil, gluten free yeast and food grade carbohydrate gums by utilizing a bread machine. The newly improved bread machine process provides a very convenient method to make very desirable fresh rice breads for the consumers in their homes, having color, volume and instrumental texture that is comparable to white wheat and whole wheat breads at about one fifth or less of the cost of commercial rice breads.

351
Texture profile of oats bars. E.A. Enriquez and R.L. Vidal-Quintanar. University of Sonora.

Sensory profile of oats cookies depends on the formulation. A good sensory profile is a factor of success in the development of new food products. Sensory texture profiles were evaluated by a trained panel (n = 9), using a 15 cm line scale. Eight sensory attributes of texture, and their intensity were developed by describing differences among 20 different foods, and validated among 5 commercial oat bars. The attributes were adhesiveness, cohesiveness, hardness, fracturability, gumminess, chewiness, adhered particles, and particle size. After training, the experiment was run on three formulas of oats bars, the natural, with chocolate, and with raisins. The bars had different profiles, the chocolate bar had less intensity values in all attributes, but fracturability; and the raisins bar had higher intensity values in all attributes. The formula had a significant effect on the profile of the three bars. Chocolate, and raisins produced differences in adhesiveness, cohesiveness, hardness, and chewiness. The fracturability, particle size, and adhered particles showed less intense changes in the oat chocolate, and in the oat raisins formulas than in the natural oat bar. Gumminess, and adhesiveness had a very high correlation (0.82), and cohesiveness had a very good correlation with hardness (0.66), and gumminess (0.66). Chocolate makes a softer, and less chewy oat bars than raisins.

352
The properties of baked and fried tortilla chips fortified with mechanically-expelled soy flour. M. DE LA TORRE (1), M.E. Barron (1), M.N. Riaz (1), and L.W. Rooney (2). (1) Food Protein R&D Center, Texas A&M University, College Station, TX 77843-2476; (2) Cereal Quality Lab., Texas A&M University, College Station, TX 77843-2474.

Soybeans have isoflavones which may lower cholesterol and prevent cancer in humans. Producers have to either mask or reduce the "beany" flavor of soy as well as to understand how the protein affects the texture of their product. The main objectives of this project were to: produce partially defatted soy flour and use this flour in baked and fried tortilla chips. Food grade soybeans were flaked and mechanically expelled to obtain partially defatted soy flour with 7.2 percent (p) oil. Insta Pro (600 Jr.) extruder was used to produce a semi-fluid extrudate, which was processed in a continuous screw oil-expeller to obtain oil and cake. The cake was ground to produce partially defatted soy flour. Corn dry masa flour was mixed with 0 (control), 10, 20 and 30% soy flour substitution, hydrated into masa, sheeted, formed and baked in a three-pass oven. The equilibrated tortilla was either baked in an air-impingement oven or fried in oil. Baked tortilla chips with 30% soy flour substitution required significantly greater force to break and were less susceptible to breakage during handling than baked and fried control and 10% soy flour substitution tortilla chips. Soy protein increased peak force and chip thickness. Sensory evaluation found no significant differences in overall flavor among all the treatments. Consumers could not detect "beany" flavors in any of the samples. However, baked tortilla chips with 30% soy flour substitution were the least crunchy and friable. Partially defatted soy flour can be added at 10-30% levels in tortilla chips to significantly improve nutritional quality without adversely affecting their organoleptic qualities. The effect of frying and processing on isoflavones will be discussed.

357
Hard red spring wheat and yellow alkaline noodle quality. I. Effect of genotypes on noodle quality characteristics. N.C. TADATADA and M. Chakraborty. Cereal and Food Sciences, NDSU, Fargo, ND 58105.

Yellow alkaline noodles (YAN) require high gluten strength and moderate starch swelling properties, both of which can be obtained from selected hard red spring (HRS) wheat genotypes. However, due to broad genotypic variability among commercial HRS genotypes, little is known about genotypes most ideal for making YAN of optimum quality. This study was carried out to 1) compare the quality characteristics of YAN made from top commercial HRS wheat genotypes grown at three different locations in ND, and 2) understand how differences in protein and starch characteristics, and GxE effects influence noodle color and textural quality. The protein content of the genotypes ranged from 13.2% to 14.5%, mixograph peak height from 5.5 min to 8.0 min, flour swelling volume (FSV) from 14.3 mL/g to 22.0 mL/g, amylose content from 21.6% to 26.6%, RVA peak viscosity from 220 RVU to 260 RVU, and setback from 94 RVU to 121 RVU. GxE effects were non significant for mixograph peak height, amylose content, RVA setback, noodle brightness (L*) and noodle yellowness (b*), which is consistent with previously reported results. The genotypes exhibited better noodle color stability after 24 hr when stored at refrigerated, compared to room temperature. Most genotypes produced noodles of acceptable texture, except for partial waxy cv. 'Parshall', which exhibited the highest starch swelling characteristics, a trait unsuitable of YAN quality.

358
Hard red spring wheat and yellow alkaline noodle quality. II. Effect of flour particle size on noodle quality characteristics. N.C. TADATADA and M. Chakraborty. Cereal and Food Sciences, NDSU, Fargo, ND 58105.

Flour particle size is known to influence the cooking and textural properties of Asian white salted noodles (WSN). This study evaluated the texture and color quality of yellow alkaline noodles (YAN) made with flours obtained from six commercial hard red spring (HRS) wheat genotypes, varying in their particle sizes. The genotypes were milled on a Buhler durum experimental mill, and the farina obtained were further reduced in the reduction head of the Brabender Quadromat Sr., and then separated by sieving, to obtain three particle size granulations: 1) coarse (>180 to <212 microns), 2) medium (>150 to <180 microns), and 3) fine (<125 microns). YAN was made using standard procedures and evaluated for cooking, textural and color properties. Fine particle size correlated with high starch damage and water absorption, which is in agreement with previously reported data on WSN. However, particle size did not have a significant effect on noodle cooking time, cooking loss, noodle firmness and chewiness values, possibly due to the high protein content of the selected HRS genotypes. Coarse flours gave higher ash content, which correlated negatively with noodle color brightness (L*), whereas, fine flours had significantly higher noodle color brightness. Results suggest that finer particle size of HRS flours significantly improves the color stability of YAN; however, noodle texture is more strongly influenced by genotypes, and less by particle size.

359
Mungbean-durum composite pasta, a non-traditional food. J. LI and C.E. Walker. Department of Grain Science, KSU, Manhattan, KS 66506-2201.

Mungbean is known as an oriental food, usually appearing as mungbean noodles (the clear oriental noodle made from mungbean starch) or as mungbean sprouts. Unlike traditional durum wheat semolina, it doesn't contain gluten but does have a high protein content (average 22%). Mungbean's high lysine content (436 mg Lys / g nitrogen) makes it possible to build a balanced formula with wheat since lysine is deficient in wheat (201 mg Lys / g nitrogen). Its yellowish color (after dehulling) is similar to the durum semolina traditionally used for pasta making. However, little has been published on mungbean's pasta making properties. Various blends with semolina at different water absorptions were used to make elbow macaroni. Optimum cooking time, cooking loss, color and texture (firmness) analysis will be compared with the 100% durum semolina macaroni control.

369a
Comparison of different strip length for evaluating rheological properties of tortillas. H. SINGH (1), R.K. Lyne (2), O.K. Chung (2), P.A. Seib (1), and G.L. Lookhart (2). (1) Department of Grain Science & Industry, Kansas State University, Manhattan, KS 66506; (2) USDA-ARS-GMPRC, Hard Winter Wheat Quality Laboratory, Manhattan, KS 66502.

Inherent variations during tortilla processing and the product itself have been major hurdles in objective measurements of rheological and textural properties. Tear and stress relaxation (SR) were measured using a texture analyzer (TAXT2 Plus) on the three-sized strips, including short, medium, and long (37, 60, and 75 mm, respectively) with 35-mm width. For the 1st set of experiments, six each of short, medium, and long strips were cut from the same tortilla and it was replicated three times. For the 2nd set of experiments, 30 short, 20 medium, and 16 long strips were cut from each tortilla. In both sets of experiments, the max tear force decreased (approximately 32%), the distance of rupture increased (approximately 74%), and the area under the curve (absorbed energy) increased (58%) by increasing strip length of 37 to 75 mm. The % coefficient of variance (CV) values were 10 to 15% by the strip length, 21% for the area under the curve, and only 1 to 3% for the %SR. The increase in %SR was from 52.88 and 52.70 to 66.81 and 67.26, respectively, for both sets of experiments, showing the consistency of the data within one tortilla and within a set of tortillas. However, %CV varied 10–27% for the force required to stretch the tortilla to 1 mm during SR, likely due to the variation resulting from only one or two low data points from possible non-homogeneous weaker areas of the tortillas. The conclusions were: (a) short (37-mm) strips were as reliable as medium (60-mm) or long (75-mm) strips for measuring rheological properties of tortillas; (b) they showed the same % changes, irrespective of the length for both sets of experiments; and (c) the %SR values showed the smallest %CV values.

369b
The staling of wheat flour tortillas studied by a texture analyzer and SE-HPLC. H. SINGH (1), R.K. Lyne (2), O.K. Chung (2), P.A. Seib (1), and G.L. Lookhart (2). (1) Department of Grain Science & Industry, Kansas State University, Manhattan, KS 66506; (2) USDA-ARS-GMPRC, Hard Winter Wheat Quality Laboratory, Manhattan, KS 66502.

Staling has been a major cause of quality loss in tortillas but has been poorly understood at the molecular level. This research was a study of the changes involved in staling using a texture analyzer (TAXT2 Plus) and size-exclusion high-performance liquid chromatography (SE-HPLC). Tortillas were made in duplicate from wheat flour. The changes in stretchability and stress relaxation (SR) with storage time, 0, 1, 2, 4, 6, and 8 days, were studied using tortilla extensibility tests. The average of values plotted against time for these parameters showed a linear relationship up to 4 days of storage, then reached a plateau. When stretchability was followed from day 0 to day 8, the max force increased from 6.5 to 12 N and the modulus of deformation from 1.5 to 9.99 N/mm. Stress relaxation, a determinant of viscoelastic behavior, decreased by approximately 10% during 8 days of storage. Another batch of tortillas from the same processing day were freeze-dried after similar storage times, ground, sieved (150 µm), and used to follow changes in extractable protein (in 1-propanol, 50%) using SE-HPLC. The decrease in polymeric void volume peak in the SE-HPLC chromatogram with increase in storage time suggested the involvement of protein during staling of tortillas.