bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Influences on Flour Composition, Dough Rheology, and Baking Quality of Spring Wheat
Authors: Mikhaylenko G. G. , Czuchajowska Z. , Baik B.‐K. , Kidwell K. K.
Published: June 2007

The highly variable environmental conditions across the Pacific Northwest (PNW) influence the milling and baking quality of wheat grain produced in this region. This study was conducted to compare the flour composition, dough rheology, and baking quality of soft and hard spring wheat grain produced in diverse environments. Thirteen soft and five hard spring wheat cultivars were grown at Lind, WA (semiarid) and Fairfield, WA (high precipitation) for three years. Grain was evaluated for flour composition, rheology, and experimental baked product quality. Flour composition, rheological properties, and baking qualities were primarily influenced by the environment. Protein contents, microSDS values, and water absorption levels were significantly (P < 0.0001) higher for all cultivars grown at Lind compared with those from Fairfield. Cookie diameters were larger (P < 0.0001) for soft flours from Fairfield, whereas loaf volumes were higher (P < 0.0001) for hard wheat flours from Lind. Results indicate that producing soft or hard wheat outside of its optimal climatic zone reduces experimental baked product quality.
In Vitro Binding of Bile Acids by Rice Bran, Oat Bran, Wheat Bran, and Corn Bran
Authors: Kahlon T. S. , Chow F. I.
Published: June 2007

The in vitro bile acid binding by rice, oat, wheat, and corn brans was determined using a mixture of bile acids normally secreted in human bile at a physiological pH of 6.3. The objective of the study was to relate bile acid binding of cereal brans to health promoting properties. Three experiments were conducted testing substrates on an equal weight (dry matter) basis, an equal total dietary fiber (TDF) basis, and an equal TDF and equal fat basis. Each experiment was repeated to validate the results (for a total of six experiments). The relative in vitro bile acid binding of the cereal brans on an equal TDF basis considering cholestyramine as 100% bound was rice bran 51%, wheat bran 31%, oat bran 26%, and corn bran 5%. The data suggest that cholesterol lowering by rice bran appears to be related to bile acid binding. The primary mechanism of cholesterol lowering by oat bran may not be due to bile acid binding by soluble fiber. Bile acid binding did not appear to be proportional to the soluble fiber content of the cereal brans tested. Bile acid binding by wheat bran may contribute to cancer prevention and other healthful properties.
Effect of Rice Blast and Sheath Blight on Physical Properties of Selected Rice Cultivars
Authors: Candole B. L. , Siebenmorgen T. J. , Lee F. N. , Cartwright R. D.
Published: June 2007

Observations in 1997 indicated a significant reduction in kernel bulk density and head rice yield of rice cultivar LaGrue due to blast (Pyricularia grisea). A more detailed study on rice cultivar M202 in 1998 confirmed such observations but it also showed negative effects of blast on other physical properties of rice. Rough rice from blast‐infected panicles was drier by 7–10 percentage points and 10% thinner than rough rice from blast‐free panicles. Blast also caused incidences of chalky, unfilled, and fissured kernels that were 21, 30, and 7 percentage points higher, respectively. The effects of sheath blight (Rhizoctonia solani) on kernel thickness and moisture content of rice cultivars Cocodrie, Cypress, Drew, and LaGrue were similar to the effect of blast on M202. Sheath blight generally reduced kernel bulk density but did not significantly affect head rice yield of the cultivars in 1997 and 1998 (except in one sample of Drew). There was a general trend toward higher incidences of unfilled, chalky, and fissured kernels in sheath‐blight‐infected samples. The data indicated that blast could be a significant preharvest factor in causing high variability in physical properties as well as in reducing the milling quality of rice. Sheath blight is also a potentially significant preharvest factor in affecting these properties in situations where sheath blight pressure is high.
Characterization of Oat Endoproteinases that Hydrolyze Oat Globulins
Authors: Mikola Markku , Jones Berne L.
Published: June 2007

During the germination of oats, the major seed storage proteins (globulins) are hydrolyzed by endoproteinases. We have used two methods to characterize these endoproteinases. A qualitative PAGE method that used oat globulins as gel‐incorporated substrates was used to determine which enzymes hydrolyzed the globulins. The proteolytic hydrolysis products were studied by hydrolyzing the globulins in vitro with the endoproteinases and analyzing the products by SDS‐PAGE. Class‐specific proteinase inhibitors were used to show that the globulin hydrolyzing enzymes were cysteine‐class proteinases. The proteinases were active at pH 3.8. Using the gel analysis method, a little activity was present at the beginning of seed germination, but the major activity only appeared on the sixth day of germination. Extracts from four‐day germinated oats contained cysteine proteinases that hydrolyzed the globulins in vitro to form a polypeptide of intermediate size (MW ≈34,500). Cysteine proteases from an eight‐day germinated sample totally hydrolyzed the globulins in <1 hr. Very little hydrolysis occurred at pH 6.2, the pH of germinated oats endosperm tissue. The fact that hydrolysis occurred quickly at pH 3.8 implies that there is probably pH compartmentalization within the endosperm, with some areas of the seed having a low pH value where the globulins can be degraded.
Characterization of Thiamin‐Binding Protein from Wheat Germ
Authors: Adachi Takashi , Watanabe Katsumi , Mitsunaga Toshio
Published: June 2007

A thiamin‐binding protein was isolated from wheat germ (Triticum aestivum). Its molecular mass was estimated as 120,000 Da consisting of two 56,000‐subunits. The protein contained a large amount of glutamine or glutamic acid (15.4 mol%), arginine (12.5 mol%), and glycine (12.0 mol%). The levels of tyrosine, methionine, tryptophan, and cysteine in the protein were low. Optimum pH for its thiamin‐binding activity was pH 8.0. It bound free thiamin specifically, not thiamin phosphates. The apparent dissociation and maximum bound values for the thiamin‐binding were 2.52 μM and 9.34 nmol/mg of protein, respectively. Properties of the thiamin‐binding protein from wheat germ were similar to those of the thiamin‐binding protein from rice seeds, but not from buckwheat, sesame, or sunflower seeds.
In Vitro Polymerization of Wheat Glutenin Subunits with Inorganic Oxidizing Agents. I. Comparison of Single‐Step and Stepwise Oxidations of High Molecular Weight Glutenin Subunits
Authors: Veraverbeke Wim S. , Larroque Oscar R. , Békés Frank , Delcour Jan A.
Published: June 2007

High molecular weight glutenin subunits (HMW‐GS) were isolated from wheat flour and polymerized in vitro at pH 3.0 with different oxidizing agents (KBrO3, KIO3, H2O2). An oxidation protocol with single addition of oxidant (single‐step oxidation) was compared with a set‐up in which the oxidant was added in multiple steps (stepwise oxidation). Changes in size distribution were evaluated with size‐exclusion HPLC, multilayer SDS‐PAGE, and flow‐field flow fractionation (flow‐FFF). Flow‐FFF is particularly suitable for measuring changes in glutenin size in the very high size ranges. In order of increasing sizes of the resulting polymers, the different oxidizing agents could be ranked as KBrO3 < KIO3 < H2O2. However, none of the oxidation conditions allowed for a complete polymerization of HMW‐GS. Interestingly, it was found that high concentrations of KIO3 negatively affect the degree of polymerization. A similar observation was not made with KBrO3 or H2O2. SDS‐PAGE showed that y‐type HMW‐GS particularly failed to incorporate in glutenin polymers. Simultaneously, these HMW‐GS displayed higher mobilities on SDS‐PAGE that can be ascribed to the formation of intrachain SS bonds. Possible explanations for the incomplete polymerization of HMW‐GS are given.
Observations on the α‐Amylolysis Pattern of Some Waxy Maize Starches from Inbred Line Ia453
Authors: Bertoft Eric , Boyer Charles , Manelius Robin , Åvall Ann‐Kristin
Published: June 2007

Maize starches of the endosperm mutants waxy (wx), dull:waxy (duwx), and amylose‐extender:dull:waxy (aeduwx) from inbred line Ia453 lack amylose. However, in addition to high molecular weight (HMW) amylopectin, the duwx and aeduwx starches contained 40 and 80%, respectively, intermediate branched material of low molecular weight (LMW). As gelatinized, the amylopectin of the wx starch was easily hydrolyzed into small dextrins by the α‐amylase of B. amyloliquefaciens, but components of duwx and aeduwx possessed partial resistance to amylolytic attack. Residual material of intermediate size obtained by a 4‐hr α‐amylolysis could not be separated from LMW dextrins by fractional precipitation in methanol. It is suggested that this material possessed a more regularly branched structure, in which the d‐glucosyl chain segments were too short to allow α‐amylase action. The granular starches of duwx and aeduwx genotypes were initially considerably more resistant than the wx sample to α‐amylase attack. This was possibly due to an altered structure in the amylopectin component or the high content of intermediate material in the former granules.
Hybrid Variability and Effect of Growth Location on Corn Fiber Yields and Corn Fiber Oil Composition
Authors: Singh Vijay , Moreau Robert A. , Haken Armgard E. , Eckhoff Steven R. , Hicks Kevin B.
Published: June 2007

The variability in commercial corn hybrids for corn fiber yields, amounts of extractable oil, and levels of individual and total phytosterol components in corn fiber oil was determined. Also, the effect of growth location on fiber yields, fiber oil content, and the levels of individual and total phytosterol compounds was determined. Significant variation was observed in the commercial hybrids for fiber yield (13.2–16.6%) and fiber oil yield (0.9–2.4%). No significant correlation was observed between fiber and oil yields. Significant variations in the commercial corn hybrids were also observed in the individual phytosterol compounds in corn fiber oil: 2.9–9.2% for ferulate phytosterol esters (FPE); 1.9–4.3% for free phytosterols (St); and 6.5–9.5% for phytosterol fatty acyl esters (St:E). Positive correlations were observed among the three phytosterol compounds in the corn fiber oil (R = 0.75 for FPE and St:E; 0.48 for St:E and St; and 0.68 for FPE and St). The effect of location on dependent variables was also significant. The same hybrids grown at different locations showed a variation (range) of 4.0–17.5% for FPE, 4.9–12.2% for St:E, and 1.95–4.45% for St. Relative ranking of hybrids with respect to phytosterol composition was consistent for almost all of the growth locations.
Breadmaking Quality Estimation By Fast Spectrophotometric Method
Authors: Tosi E. A. , Ré E. D. , Carbone L. , Cuniberti M.
Published: June 2007

A fast method to estimate wheat breadmaking quality diminution as a result of excessive thermal treatment during drying is proposed. Proteins that remain in soluble after drying were extracted with a solution of phosphoric acid plus ethanol, and colorimetrically quantified after dyeing with Coomassie Brilliant Blue G and measuring at 595 nm. A decrease in absorbance values indicates a decrease in loaf volume and breadmaking quality. The application of the proposed technique required ≈30 min.
Contribution of Hydrophobic Soluble Gluten Proteins, Fractionated by Hydrophobic Interaction Chromatography in Highly Acetylated Agarose, to Dough Rheological Properties
Authors: Torres P. I. , Vazquez‐Moreno L. , Ledesma‐Osuna A. I. , Medina‐Rodriguez C.
Published: June 2007

Hydrophobic interaction chromatography with highly acetylated agarose in 1‐mL columns was used to fractionate gliadins and acid‐soluble glutenins. Proteins were eluted in two fractions, the first with acetate buffer (pH 3.6) containing 35% propanol, and the second with Tris buffer in 8M urea. The proportion of eluted protein in the second fraction was called the surface hydrophobicity index. The study included 20 wheat samples of different baking qualities. Multiple regression analysis using the general linear model combined with the stepwise technique was used to relate the surface hydrophobicity index of soluble gluten proteins to specific dough rheological characteristics. Surface hydrophobicity index of gliadins and acetic acid soluble glutenins explained part of the variability of swelling index, extensibility, and work of deformation (dough strength) measured with the alveograph, and part of the farinograph water absorption variability, but showed no relationship to dough mixing characteristics. Hydrophobic soluble gluten proteins fractionated by hydrophobic interaction chromatography (HIC) explained a part of the variability of dough rheological properties.
Glassy State Transition and Rice Drying: Development of a Brown Rice State Diagram
Authors: Perdon A. , Siebenmorgen T. J. , Mauromoustakos A.
Published: June 2007

The effect of moisture content (MC) on the glass transition temperature (Tg) of individual brown rice kernels of Bengal, a medium‐grain cultivar, and Cypress, a long‐grain cultivar, was studied. Three methods were investigated for measuring Tg: differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and dynamic mechanical analysis (DMA). Among these methods, TMA was chosen, because it can also measure changes in the thermal volumetric coefficient (β) of the kernel during glass transition. TMA‐measured Tg at similar MC levels for both cultivars were not significantly different and were combined to generate a brown rice state diagram. Individual kernel Tg for both cultivars increased from 22 to 58°C as MC decreased from 27 to 3% wb. Linear and sigmoid models were derived to relate Tg to MC. The linear model was sufficient to describe the property changes in the MC range encountered during rice drying. Mean β values across both cultivars in the rubbery state was 4.62 × 10‐4/°C and was higher than the mean β value of 0.87 × 10‐4/°C in the glassy state. A hypothetical rice drying process was mapped onto the combined state diagram generated for Bengal and Cypress.
Susceptibility of Waxy Starch Granules to Mechanical Damage
Authors: Bettge A. D. , Giroux M. J. , Morris C. F.
Published: June 2007

Starch samples isolated from wheat flour that represented four possible waxy states (0, 1, 2, and 3‐gene waxy) were subjected to crushing loads under both dry and wet conditions. Calibrated loads of 0.5–20 kg were applied to the starch samples and the percentage of damaged granules was visually determined. Under dry crushing conditions, starches containing amylose (0, 1, and 2‐gene waxy) had between 1% (5‐kg load) to 3% (15‐ and 20‐kg load) damaged granules, whereas waxy starch (3‐ gene waxy; <1% amylose) began rupturing at 0.5‐kg load (3.5% damaged granules) and had 13% damaged granules when ≥10‐kg load was applied. Under wet crushing conditions, normal and partial waxy starch (0, 1, and 2‐gene waxy) showed little difference in percentage of damaged granules when compared to the results of dry crushing. Waxy starch (3‐gene waxy), however, showed substantially increased numbers of damaged granules: 12% damaged granules at 0.5‐kg load, rising to 55% damaged granules at 15‐kg load. The results indicate that waxy starch granules are less resistant to mechanical damage than normal starch granules. Furthermore, blends of normal and waxy wheats or wheat flours intended to have a particular amylose‐amylopectin ratio will be a complex system with unique processing and formulation considerations and opportunities.
Scarification and Degermination of Sorghum for Grits Production: Effects of Hybrid and Conditioning
Authors: Suroso Janti , Flores Rolando A. , Boyer John E.
Published: June 2007

Three sorghum hybrids were tempered and decorticated with an abrasive‐type mill (scarifier) to produce low‐ash and low‐fat grits. The effects of tempering time and temperature were investigated, and the optimum tempering conditions for obtaining low‐ash and low‐fat grits were found for each sorghum hybrid. The conditions were 3 min at 30°C for bronze sorghum with heteroyellow endosperm, 40 min at 40°C for white sorghum with white endosperm, and 10 min at 20°C for red sorghum with white endosperm. The grits yields were low using the scarifier, hence, another abrasive‐type mill was investigated for improving grits yields. A modified experimental corn decorticator‐degerminator was used to dry‐mill the three sorghum hybrids tempered to the optimum conditions found with the scarifier. The yields were 45.3% grits with 0.23% ash and 0.18% fat for the bronze/heteroyellow hybrid, 49.1% grits with 0.22% ash and 0.36% fat for white/white hybrid, and 44.2% grits with 0.20% ash and 0.22% fat for red/white hybrid. This study showed that grits yields were higher and ash and fat contents were lower when sorghum was processed with the decorticator‐degerminator than with the scarifier under the same optimum conditioning.
Packing Characteristics of Starch Granules
Authors: Willett J. L.
Published: June 2007

The rheological properties of granular materials and dispersions of solid particles in fluids are dependent on the packing characteristics of the particles. Maximum packing fractions (Φm) have been measured for corn, wheat, rice, potato, and amaranth starches, in the dry state and dispersed in either ethanol or hexane, using a tapping method. The observed maximum packing fraction increases with tapping time to a constant value. Values measured for dry starches were lower than those measured in liquids and reflect the effects of granule shape and intergranular friction. Values measured in fluids for potato, corn, and wheat starches were all similar in magnitude, and in the range of values (0.58–0.63) for random loose packing and random close packing of monodisperse spheres. Values for amaranth and rice starches were significantly lower due to agglomeration and clumping of individual granules. Blends of corn and potato starches show a slight enhancement of packing, with some Φm values greater than potato starch, consistent with data for bimodal blends of spheres. Blends of rice and potato starches displayed enhanced packing above ideal mixing but did not exceed the packing fraction of the potato starch. Knowledge of starch packing fractions is required for fundamental understanding of the rheological properties of granular starch‐filled materials and important for predicting processing characteristics.
Use of SDS to Extract Sorghum and Maize Proteins for Free Zone Capillary Electrophoresis (FZCE) Analysis
Authors: Bean S. R. , Hicks C. , Tuinstra M. , Lookhart G. L.
Published: June 2007

Two different extraction methods for extracting sorghum (Sorghum bicolor L. Moench.) storage proteins for free zone capillary electrophoresis (FZCE) analysis were compared. A traditional solvent based on 60% t‐butanol was compared with a pH 10 borate buffer containing the anionic detergent SDS followed by precipitation of nonkafirins using 60% t‐butanol. FZCE analysis of both types of extracts showed identical patterns, despite the fact that the SDS should have given all proteins equal charge‐to‐mass ratios. This methodology was also successfully applied to maize proteins. The use of t‐butanol to precipitate nonkafirins, combined with electrophoresis at low pH, is thought to have removed the SDS from the storage proteins. The SDS extraction procedure produced more stable extracts for FZCE analysis. These extracts could also be used directly for SDS capillary electrophoresis (SDS‐CE) separations. Kafirins from 15 genotypes were extracted with this procedure and analyzed by FZCE and SDS‐CE. Resolution of the kafirins by FZCE was much higher than the SDS‐CE, demonstrating that the kafirin proteins possessed a high level of charge density variability within a relatively small molecular size distribution. Two distinct groups of α‐kafirins could be seen in the FZCE electropherograms.
Alkaline Processing (Nixtamalization) of White Mexican Corn Hybrids for Tortilla Production: Significance of Corn Physicochemical Characteristics and Process Conditions
Authors: Sahai D. , Mua J. P. , Surjewan I. , Buendia M. O. , Rowe M. , Jackson D. S.
Published: June 2007

Five white corn hybrids were processed (nixtamalized) using 10 different processing conditions; tortillas were prepared to establish relationships between corn composition, physical characteristics, and nixtamalization process or product properties. Corn hybrids were characterized by proximate analysis and by measuring Stenvert hardness, Wisconsin breakage, percent floaters, TADD overs, thousand‐kernel weight, and test weight. Corn characteristics were correlated with process and product variables (effluent dry matter loss and pH; nixtamal moisture and color; masa moisture, color, and texture; and tortilla moisture, color, and rollability). Process and product variables such as corn solid loss, nixtamal moisture, masa texture, and tortilla color were influenced not only by processing parameters (cook temperature, cook time, and steep time) but also depended on corn characteristics. Significant regression equations were developed for nixtamalization dry matter loss (P < 0.05, r2 = 0.79), nixtamal moisture (P < 0.05, r2 = 0.78), masa gumminess (P < 0.05, r2 = 0.78), tortilla texture (P < 0.05, r2 = 0.77), tortilla moisture (P < 0.05, r2 = 0.80), tortilla calcium (P < 0.05, r2 = 0.93), and tortilla color a value (P < 0.05, r2 = 0.87).
Functional and Digestive Characteristics of Extruded Rice Flour
Authors: Bryant Rolfe J. , Kadan Ranjit S. , Champagne Elaine T. , Vinyard Bryan T. , Boykin Debbie
Published: June 2007

Waxy (short grain), long grain, and parboiled (long grain) rice flours were extruded using three different temperatures and five different water feed rates. The water absorption and water solubility index of the extrudates was 0.67–5.86 and 86.45–10.03%, respectively. The fat absorption index was similar to that of unextruded flours with an average value of 0.96 g/g ± 0.12. Bulk density decreased with an increase in moisture, except waxy rice, which had a quadratic relationship. The viscosity profiles for long grain and parboiled rice were similar. Both initially increased in viscosity (>130 RVU), then decreased to ≈40 RVU. The final viscosity was ≈60 RVU. Waxy rice viscosity remained low (<20 RVU), then doubled upon cooling. The main difference in the digestion profiles was due to temperature. The flours extruded at 100°C digested significantly slower than those extruded at 125 and 150°C. Significant differences were not detected for a given temperature and moisture (P > 0.05) except for long grain and parboiled rice extruded at 100°C and 15% added moisture (F = 4.48, P = 0.03) and 150°C and 20% added moisture (F = 3.72, P = 0.05). Moisture appeared to have little effect for a given temperature, except when parboiled rice was extruded at 150°C. The digestion rate for 11 and 25% added moisture was significantly less than that for 20% (P ≤ 0.05).
Effect of Sucrose on Glass Transition, Gelatinization, and Retrogradation of Wheat Starch
Authors: Jang J. K. , Lee S. H. , Cho S. C. , Pyun Y. R.
Published: June 2007

Differential scanning calorimetry (DSC) was used to study the effect of sucrose on wheat starch glass transition, gelatinization, and retrogradation. As the ratio of sucrose to starch increased from 0.25:1 to 1:1, the glass transition temperature (Tg, Tg′) and ice melting enthalpy (ΔHice) of wheat starch‐sucrose mixtures (with total moistures of 40–60%) were decreased to a range of −7 to −20°C and increased to a range of 29.4 to 413.4 J/g of starch, respectively, in comparison with wheat starch with no sucrose. The Tg′ of the wheat starch‐sucrose mixtures was sensitive to the amount of added sucrose, and detection was possible only under conditions of excess total moisture of >40%. The peak temperature (Tm) and enthalpy value (ΔHG) for gelatinization of starch‐sucrose systems within the total moisture range of 40–60% were increased with increasing sucrose and were greater at lower total moisture levels. The Tg′ of the starch‐sucrose system increased during storage. In particular, the significant shift in Tg′ ranged between 15 and 18°C for a 1:1 starch‐sucrose system (total moisture 50%) after one week of storage at various temperatures (4, 32, and 40°C). At 40% total moisture, samples with sucrose stored at 4, 32, and 40°C for four weeks had higher retrogradation enthalpy (ΔH) values than a sample with no sucrose. At 50 and 60% total moisture, there were small increases in ΔH values at storage temperature of 4°C, whereas recrystallization of samples with sucrose stored at 32 and 40°C decreased. The peak temperature (Tp), peak width (δT), and enthalpy (ΔH) for the retrogradation endotherm of wheat starch‐sucrose systems (1:0.25, 1:0.5, and 1:1) at the same total moisture and storage temperature showed notable differences with the ratio of added sucrose. In addition, Tp increased at the higher storage temperature, while δT increased at the lower storage temperature. This suggests that the recrystallization of the wheat starch‐sucrose system at various storage temperatures can be interpreted in terms of δT and Tp.
Predicting Baking Performance from Rheological and Adhesive Properties of Rye Meal Suspensions During Heating
Authors: Repeckiene A. , Eliasson A.‐C. , Juodeikiene G. , Gunnarsson E.
Published: June 2007

Rheological methods were used to study the behavior of rye meal suspensions during a time‐temperature treatment corresponding to the initial baking conditions (<70°C). Eight different rye cultivars were investigated, with four of the cultivars grown during two different years. Baking experiments included pan bread and hearth bread. Viscosity, falling number, and the amount of adhesive material present during heating were measured. The storage (G′) and loss (G″) moduli increased during a temperature sweep from 45°C, reaching a maximum at 62.1–67.1°C. At the same time, the amount of adhesive material increased. A further increase in temperature caused a decrease in G′ and G″, whereas the amount of adhesive material continued to increase. The mechanical spectra (G′ or G″ vs. frequency) showed that the rye meal suspensions had gel‐like behavior at 45°C which turned into behavior typical of a strong gel at 70°C. The rye meals performing the best in hearth bread baking gave intermediate values of G′ and G″ and high values of the phase shift (δ) at 45°C. During the temperature sweep, the G′ values of these rye meal suspensions increased slowly to a maximum of 62.1–67.1°C.
Comparison of Physicochemical Properties and Structures of Sugary‐2 Cornstarch with Normal and Waxy Cultivars
Authors: Perera C. , Lu Z. , Sell J. , Jane J.
Published: June 2007

Starches from normal, waxy, and sugary‐2 (su2) corn kernels were isolated, and their structures and properties determined. The total lipid contents of normal, waxy, and su2 corn starches were 0.84, 0.00, and 1.61%, respectively. Scanning electron micrographs showed that normal and waxy corn starch granules were spherical or angular in shape with smooth surfaces. The su2 starch granules consisted of lobes that resembled starch mutants deficient in soluble starch synthases. Normal and waxy corn starches displayed A‐type X‐ray patterns. The su2 starch showed a weak A‐type pattern. The chain‐length distributions of normal, waxy, and su2 debranched amylopectins showed the first peak chain length at DP (degree of polymerization) 13, 14, and 13, respectively; second peak chain length at DP 45, 49, and 49, respectively; and highest detectable DP of 80, 72, and 76, respectively. The su2 amylopectin showed a higher percentage of chains with DP 6–12 (22.2%) than normal (15.0%) and waxy (14.6%) amylopectins. The absolute amylose content of normal, waxy, and su2 starches was 18.8, 0.0, and 27.3%, respectively. Gel‐permeation profiles of su2 corn starch displayed a considerable amount of intermediate components. The su2 corn starch displayed lower gelatinization temperature, enthalpy change, and viscosity; a significantly higher enthalpy change for melting of amylose‐lipid complex; and lower melting temperature and enthalpy change for retrograded starch than did normal and waxy corn starches. The initial rate of hydrolysis (3 hr) of the corn starches followed the order su2 > waxy > normal corn. Waxy and su2 starches were hydrolyzed to the same extent, which was higher than normal starch after a 72‐hr hydrolysis period.
Mechanical Starch Damage Effects on Wheat Flour Tortilla Texture
Authors: Mao Yufeng , Flores Rolando A.
Published: June 2007

To investigate the effects of mechanically damaged starch and flour particle size on the texture of fresh and stored flour tortillas, two commercial hard red winter wheat flour samples were reground four times using decreasing roll gaps. Tortillas were made with a modified hot‐press procedure. Texture characteristics were measured after tortillas were stored 2 hr (fresh tortilla), 2 days, and 4 days. Damaged starch and particle size significantly affected (P < 0.05) flour water absorption, dough extensibility and resistance, and dough viscosity. As damaged starch increased and particle size decreased, the flour tortillas became less stretchable, the maximum force of Kramer shear decreased, and firmness and rollability increased. The effects of damaged starch and particle size on stretchability and Kramer shear were greater in fresh tortillas than in stored tortillas and became smaller as the storage time increased. However, the effects of damaged starch and particle size on rollability and firmness were smaller in fresh tortillas than in stored tortillas but became greater as the storage time increased.
Two‐Site Sandwich ELISA for Discriminating Different Gli‐1 (gliadin)/Glu‐3 (LMW‐glutenin subunit) Alleles in Hexaploid Wheat
Authors: Partridge Michael A. K. , Hill Amanda S. , Blundell Malcolm J. , Skerritt John H.
Published: June 2007

A panel of monoclonal antibodies was assessed in a two‐site sandwich ELISA format, using both reduced glutenin subunit and gliadin‐rich antigen preparations, to develop assays that could potentially discriminate between Gli‐1/Glu‐3 allelic variants in hexaploid wheat. Each antibody was assessed as the immobilized and the enzyme‐labeled antibody in the sandwich ELISA. A number of antibody combination were identified which could discriminate different Gli‐1/Glu‐3 allelic variants in a population of doubled haploid lines derived from a cross between parents that differed at each of these loci. Certain labeled antibodies consistently detected allelic variation at a particular locus when used in conjunction with any of several immobilized antibodies. However, the level of discrimination was largely dependent on the choice of immobilized antibody. Two antibody combinations were identified that provided twofold differences in ELISA absorbances in flour extracts from different allelic variants at the Gli‐A1/Glu‐A3 and Gli‐B1/Glu‐B3 loci. By analyzing the prolamin composition of the antigen preparations, and the performance of the assays with flour extracts from a set of Gli‐1/Glu‐3 biotypes and a range of diverse cultivars, the biochemical basis for the discrimination was determined. The assays may have potential for use in high‐throughput screening in wheat breeding programs.
Effect of Sucrose on Starch Conversion and Glass Transition of Nonexpanded Maize and Wheat Extrudates
Authors: Carvalho C. W. P. , Mitchell J. R.
Published: June 2007

Nonexpanded “half products” were prepared by twin‐screw extrusion of maize and wheat of fine and coarse particle size in three levels of sucrose, 0, 10, and 20% db. The degree of starch conversion in the extrudates was determined using X‐ray diffraction, differential scanning calorimetry, and rapid viscosity analysis. Starch conversion was greater in the fine material compared with the coarse material and greater for wheat compared with maize. Sugar addition decreased starch conversion in all cases, but the effect was greater for maize compared with wheat and for the coarse material compared with the fine material. The thermal mechanical properties were studied by dynamic mechanical thermal analysis to determine the effect of sugar on the glass transition temperature (Tg) in the four different materials. As expected, the mechanically determined Tg was reduced by sugar addition. Water plasticized wheat semolina less than the other three materials. It was suggested that this was because the extruded semolina was entirely amorphous, whereas Xray analysis showed some crystallinity in the other three materials. Die swell was much less for maize grits possibly because elasticity decreased with decreasing starch conversion. The implications for the role of both water and sugar on the behavior of directly expanded extrudates are discussed.
HPLC Determination of Stability and Distribution of Added Folic Acid and Some Endogenous Folates During Breadmaking
Authors: Osseyi Elolo S. , Wehling Randy L. , Albrecht Julie A.
Published: June 2007

Bread flour was spiked with folic acid (1.40 mg/lb or 3.08 μg/g of flour) and processed into bread by the sponge and dough method. Changes that occurred to added folic acid and endogenous folate contents through different processing stages, including sponge formation, proofing, and baking, were assessed by reversed‐phase ion‐pair HPLC combined with UV and fluorometric detection. Sample extraction required α‐amylase and rat plasma deconjugase digestion, and sample preparation required purification by solid‐phase extraction. Added folic acid was measured by monitoring UV absorption at 280 nm. Four selected forms of endogenous folates including tetrahydrofolate (THF), 5‐formyl‐THF, 10‐formylfolate, and 5‐methyl‐THF were identified and quantified throughout the bread processing using a fluorescence excitation wavelength of 290 nm and emission wavelength of 350 or 450 nm. Data indicate a relatively good stability of added folic acid and native folates to the baking process, and increased endogenous folate contents in dough and bread as compared with the flour from which they were made.
Use of Proteases to Reduce Steep Time and SO2 Requirements in a Corn Wet‐Milling Process
Authors: Johnston David B. , Singh Vijay
Published: June 2007

To eliminate the diffusion barriers associated with enzyme addition during conventional steeping, we have developed a two‐stage milling procedure to evaluate the effects of enzyme addition on corn wet milling. The current study compares the effects of the addition of commercially available enzyme preparations during conventional steeping to their comparable addition in the two‐stage procedure. Results are presented in terms of yields of fiber, starch, germ, and gluten. The results demonstrate that the application of enzymes to the normal steeping step of wet milling is not an effective means of decreasing the steeping time or sulfur dioxide usage. Only when specific enzymes are added to the hydrated ground corn, using the modified two‐stage procedure, are enzymes effective in decreasing the steeping time and sulfur dioxide requirements. The overall steeping time with the two‐stage modified procedure ranges from 6 to 8 hr, representing a 67–83% reduction over the conventional process. The modified process greatly decreases, and possibly eliminates, the need for sulfur dioxide addition, while producing starch yields and quality equivalent to that from the conventional process.
Effect of Corn Milling Practices on Aleurone Layer Cells and Their Unique Phytosterols
Authors: Singh Vijay , Moreau Robert A. , Cooke Peter H.
Published: June 2007

Coarse and fine fiber fractions obtained from the corn wet‐milling processes, with and without steeping chemicals (SO2 and lactic acid), were evaluated microscopically for structure and analytically for recovery of phytosterol compounds from the fiber oil. Microscopic results showed that wet milling, with and without chemicals during steeping, changed the line of fracture between pericarp and endosperm and therefore affected the recovery of the aleurone layer in coarse (pericarp) and fine (endosperm cellular structure) fiber. Analytical results showed that most of the phytosterols and mainly phytostanols in corn fiber are contributed by the aleurone layer. Hand‐dissection studies were performed to separate the two layers that comprise the wet‐milled coarse fiber, the aleurone, and pericarp layer. Analyses revealed that the aleurone contained 8× more phytosterols than the pericarp.
Relationship Between Rheological Properties and Microstructural Characteristics of Nondeveloped, Partially Developed, and Developed Doughs
Authors: Lee L. , Ng P. K. W. , Whallon J. H. , Steffe J. F.
Published: June 2007

Farinography and mixography are two commonly used procedures for evaluating dough properties. These procedures, however, cannot separate hydration and energy input during dough development, both of which are critically important for understanding fundamental rheological properties of dough. A rheometer and laser scanning confocal microscopy (LSCM) were used to study the relationship between rheological properties and microstructural characteristics of developed (by farinograph with both shear and extensional deformations), of partially developed (by rheometer with either shear or extensional deformation), and of nondeveloped (no deformation) dough samples of wheat flours. Rheological data revealed that developed dough had the highest G* (most elastic or strong), followed by doughs partially developed with extensional deformation, and then shear deformation, and finally by nondeveloped dough. The LSCM z‐sectioning (scanning of different layers of the sample) and the analysis of amount of protein matrix showed that developed dough had the most protein matrix and nondeveloped dough had the least protein matrix. It also showed that the higher the G*, the greater the protein network. Moreover, the type of deformation appeared to contribute to the development of protein matrix and further increase the dough strength. In this study, a combination of shear and extensional deformations by farinograph produced the most protein matrix and the strongest dough, followed by extensional deformation, shear deformation, and then no deformation.
Preparative Method for In Vitro Production of Functional Polymers from Glutenin Subunits of Wheat
Authors: Beasley Helen L. , Blanchard Chris L. , Bekes Ferenc
Published: June 2007

An in vitro method for preparative‐scale production of artificial glutenin polymers utilizes a controlled environment for the oxidation of glutenin subunits (GS) isolated from wheat flour to achieve high polymerization efficiency. The functionality of in vitro polymers was tested in a 2‐g model dough system and was related to the treatment of the proteins before, during, and after in vitro polymerization. When added as the only polymeric component in a reconstituted model dough (built up from gliadin, water solubles, and starch fractions), in vitro polymers could mimic the behavior of native glutenin, demonstrating properties of dough development and breakdown. Manipulating the high molecular weight (HMW)‐GS to a low molecular weight (LMW)‐GS ratio altered the molecular weight distribution of in vitro polymers. In functional studies using the 2‐g mixograph, simple doughs built up from homopolymers of HMW‐GS were stronger than those using homopolymers of LMW‐GS. These differences may be accounted for, at least in part, by different polymer size distributions. The ability to control the size and composition of glutenin polymers shows the potential of this approach for investigating the effects of glutenin polymer size on dough function and flour end‐use quality.
Cellulosic Fiber Gels Prepared from Cell Walls of Maize Hulls
Authors: Inglett G. E. , Carriere C. J.
Published: June 2007

Cellulosic fiber gel substances were prepared from maize hulls by chemically and physically treating the pericarp cell‐wall substrate in a multistage process to disintegrate morphological cellular structure. Thermal alkaline degradation was used with impact shear in the first stage, followed by alkaline peroxidation and shear in the second stage. The degradation products were removed in the liquid supernatants at each stage. The maize fiber gels are characterized by high viscosities and hydration capacities. After drying, they can be reconstituted to the original gel form by using shear forces. The fiber gels were also dried together with hydrophilic materials to more easily reconstitute the gel form. The alkaline‐extracted hemicellulose effluents from the fiber gel preparation, including the second stage peroxidized extract, were purified and used as hydrophilic material. Oat flour hydrolyzate, an amylodextrin, also was used as a hydrophilic material. The physical properties of the gels were characterized by scanning electron microscopy and rheological evaluations.
Effect of Wheat Bran Fiber and Bran Particle Size on Fat and Fiber Digestibility and Gastrointestinal Tract Measurements in the Rat
Authors: Kahlon T. S. , Chow F. I. , Hoefer J. L. , Betschart A. A.
Published: June 2007

The effect of wheat bran (AACC hard red) and bran particle size on fat and fiber digestibility and gastrointestinal tract measurements were investigated with diets containing 5.7–10.7% dietary fiber. Fifty‐six male weanling Sprague‐Dawley rats were randomly assigned to four diets containing 5% cellulose (C5); 10.5% cellulose (C10); 21.5% coarse (2 mm) wheat bran (CB); or 22.2% fine (0.5 mm) wheat bran (FB) in a sixweek study. Dietary fiber digestibilities were significantly different (P < 0.05) among treatment diets (CB > FB > C5 > C10) but there was no effect in fat digestibility among treatments. High‐fiber diets fed to rats resulted in significantly greater wet and dry fecal weights than low‐fiber diets. Bran diets resulted in significantly higher fecal moisture than cellulose diets. Cecum lengths increased significantly with bran diets compared with cellulose diets. The CB diet resulted in significantly higher stomach weights than with cellulose diets. Stomachs were heavier and cecal lengths were greater with bran diets than with cellulose diets; however, a high‐cellulose diet resulted in increased colon weight. Except for higher fiber digestibility of coarse bran, bran particle size had no significant effects. Healthful effects of wheat bran may be associated with gastrointestinal morphology and function. Fecal bulking and decreased intestinal transit time can prevent constipation and may dilute or reduce absorption of toxic or carcinogenic metabolites, thus improving gastrointestinal health and lowering the risk of tumor development and cancer.
Categorizing Rice Cultivars Based on Cluster Analysis of Amylose Content, Protein Content and Sensory Attributes
Authors: Bett‐Garber Karen L. , Champagne Elaine T. , McClung Anna M. , Moldenhauer Karen A. , Linscombe Steve D. , McKenzie Kent S.
Published: June 2007

Presently, rice cultivars are categorized according to grain dimensions, amylose content, and alkali spreading value (gelatinization temperature type). Categorization of rice cultivars based on total sensory impact is needed. This work endeavors to divide world rices into groups based on amylose, protein, flavor, and texture properties. Ninety‐one rice samples representing 79 different cultivars and seven growing locations were separated into seven groups with Ward's Cluster Analysis. Cluster 1 included a third of the rice samples and had cultivars with a large diversity of grain shapes and amylose contents. Mean attribute scores for this cluster were near the grand mean for the collective rice samples for nearly every sensory attribute. Cluster 2 included conventional U.S. short‐ and medium‐grain cultivars. Cluster 3 included conventional U.S. medium cultivars that were produced in Louisiana. Mean sensory scores for this cluster characterized these cultivars as having relatively undesirable flavor and texture attributes. Cluster 4 included Japanese premium quality cultivars and U.S. medium‐grain cultivars developed for the Japanese market. Cluster 5 included high‐amylose, indica types that had relatively firm textural properties. Cluster 6 included relatively soft cooking, aromatic cultivars. Cluster 7 included waxy cultivars and other soft cooking grains. In several cases, the production environment (location, weather effects, etc.) influenced flavor and texture characteristics and resulted in the cultivar falling into an unexpected cluster. This categorization serves as a catalyst for indexing rice cultivars for cooking and processing qualities.
Development of a Germination Process for Producing High β‐Glucan, Whole Grain Food Ingredients from Oat
Authors: Wilhelmson A. , Oksman‐Caldentey K.‐M. , Laitila A. , Suortti T. , Kaukovirta‐Norja A. , Poutanen K.
Published: June 2007

Germination can be used to improve the texture and flavor of cereals. However, germination generally causes breakdown of β‐glucans, which is undesirable with respect to the functional properties of β‐glucan. Our aim was to assess possibilities of germinating oat without substantial loss of high molecular weight β‐glucan. Two cultivars, hulled Veli and hull‐less (naked) Lisbeth were germinated at 5, 15, and 25°C and dried by lyophilization or oven drying. Elevated germination temperatures led to an increase in Fusarium, aerobic heterotrophic bacteria, Pseudomonas spp., lactic acid bacteria, enterobacteria, and aerobic spore‐forming bacteria. Therefore, the germination temperature should be kept low to avoid excessive growth of microbes. Of the samples germinated at 15°C, only one contained low amounts of the Fusarium toxin deoxynivalenol (52 μg/kg). Germination led to the breakdown of β‐glucans, but the decrease in the molecular weight of β‐glucan was initially very slow. A short germination schedule (72 hr, 15°C) terminated with oven drying was developed to produce germinated oat with retained β‐glucan content. Compared with the native oat, 55–60% of the β‐glucan could be retained.
Influence of Arabinoxylans and Endoxylanases on Pasta Processing and Quality. Production of High‐Quality Pasta with Increased Levels of Soluble Fiber
Authors: Ingelbrecht J. A. , Moers K. , Abécassis J. , Rouau X. , Delcour J. A.
Published: June 2007

As part of a general study aiming to clarify the role of arabinoxylans (AX) in pasta processing and quality, AX were modified by the addition of endoxylanases during pasta processing. The influence on processing parameters and quality were determined. Pasta (800 g) was produced from two commercial semolinas (semA and semB) using dosages of Bacillus subtilis (XBS) and Aspergillus niger (XAN) endoxylanases of 0–0.225 Somogyi units/g of semolina. Increased dosages resulted in a drop of extrusion pressure. The endoxylanase treatments had no great effect on the resulting pasta quality (color of dry products and surface condition, viscoelastic index, and resistance to longitudinal deformations of cooked products). High dosages of XAN and XBS resulted in high levels of solubilized AX (as an extra source of soluble dietary fiber) of low molecular weight which were expected to easily leach out during the cooking process of pasta. Surprisingly, only low levels of AX were found in the cooking water, even with extremely high dosages of endoxylanases used and cooking beyond optimum time. A method is provided to obtain high‐quality pasta with increased levels of soluble fiber.