bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Determination of High Molecular Weight Glutenin Subunits of Hard Red Spring Wheat by SDS‐PAGE. II. Quantitative Effects of Individual Subunits on Breadmaking Quality Characteristics
Authors: Huang Dong Yin , Khan Khalil 
Published: June 2007

ABSTRACTHigh molecular weight (HMW) glutenin subunits were investigated in terms of “good” or “poor” subunits for determining the breadmaking quality of hard red spring wheat. Relationships between quantitative changes of individual HMW glutenin subunits and rheological properties of doughs and aggregation properties of native (nonreduced) glutenin proteins were investigated. Native glutenin proteins were separated by multistacking SDS‐PAGE procedures. Seven genotypes with the same HMW glutenin subunits (2*, 7+9, 5+10) were used in correlation studies between solubilities of individual HMW glutenin subunits and physical properties of doughs, while three genotypes with diverse baking qualities were used to investigate solubility changes of HMW glutenin subunits during dough overmixing in the mixograph. Native glutenins in total flour proteins extracted with SDS buffer were separated based on their migrations at stacking gel origins of different acrylamide concentrations. After reduction of glutenin aggregates from the different origins with β‐mercaptoethanol, compositions of HMW glutenin subunits were analyzed by densitometry. It was found that aggregates with the largest molecular weight at the 4% origin of stacking gels had much higher proportions of subunit 5 (18.8%) than those at the 12% origin (9.2%). For correlation studies, total flour proteins were fractionated into three fractions: salt‐extractable (0.5M NaCl), SDS‐soluble (2% SDS sodium phosphate buffer, pH 6.8), and insoluble residues. HMW glutenin subunits solubilized in SDS‐soluble proteins were analyzed quantitatively by densitometry of SDS‐polyacrylamide gels in relation to flour strength. The total amount of HMW glutenin subunits, x‐type subunits, and proportions of subunits 5 and 2* in SDS‐soluble proteins were found to have negative correlations with dough mixing strength (‐0.87*, ‐0.76*, ‐0.94**, and ‐0.86*, respectively, with dough stability in the mixograph). Proportions of subunit 10 solubilized in SDS buffer had a positive correlation with flour strength (0.86*). In extended mixing studies, doughs with optimum mixing and doughs overmixed to 2.5 min after the peak in the mixograph were fractionated, and their protein compositions were compared using same procedures as for flours. During extended mixing, HMW glutenin subunits with the highest molecular weight (subunit 5) increased in solubility in SDS buffer, while subunit 10 (with lower molecular weight) decreased in solubility. These results indicated that functionalities and aggregation properties of individual HMW glutenin subunits may depend mainly on their molecular weights.
Hydrodynamic Chromatography of Waxy Maize Starch
Authors: Klavons Jerome A. , Dintzis Frederick R. , Millard Merle M. 
Published: June 2007

ABSTRACTA hydrodynamic column packed with solid beads chemically bonded with N‐methyl‐d‐glucamine residues was used with 90% dimethylsulfoxide (DMSO)‐H2O mobile phase as part of a chromatographic system to characterize jet‐cooked waxy maize starch. Software calculations based on signals from refractive index and dual‐angle light‐scattering detectors indicated the column could fractionate molecular weights up to ≈5 × 108. Calculated molecular weight values for the highest molecular weight sample was greatest at the lowest flow rate of 0.1 mL/min. Values of molecular weights and radii of gyration determined by the in‐line dual‐angle light‐scattering detector were significantly less than those determined with an off‐line multiangle light‐scattering detector that examined samples that had not traveled through the hydrodynamic column. This work has demonstrated the feasibility of using a hydrodynamic column to characterize waxy maize amylopectins. However, considerations of sample shear sensitivity and questions of in‐line light scattering detection show that further efforts are required to develop and optimize a chromatographic system to characterize very high molecular weight amylopectins.
Thermal Properties of Starch from 62 Exotic Maize (Zea mays L.) Lines Grown in Two Locations
Authors: Ng K.‐Y. , Pollak L. M. , Duvick S. A. , White P. J. 
Published: June 2007

ABSTRACTThe variability in thermal properties among 62 S3 lines derived from a high‐yielding exotic corn (Zea mays) population, Antigua 1 (PI 484990), was evaluated by differential scanning calorimetry (DSC). The S3 lines were grown in Puerto Rico (1990–1991) and Georgia (1994). Separate single‐kernel starch extractions for five kernels (five replicates) from each line grown in each location were performed, and the starch was analyzed. The DSC values reported included gelatinization onset (ToG), range (RG), enthalpy (ΔHG), and peak height index (PHI) and retrogradation onset (ToR), range (RR), enthalpy (ΔHR), and percent retrogradation (%R) (an indication of the stability of gelatinized starch after storing at 4°C for 7 days). Significant differences (P < 0.05) were found among the 62 lines of Antigua 1 for ToG, RG, and PHI and highly significant differences (P < 0.01) were found for ΔHG. The starches from plants grown in Georgia (1994) had significantly (P < 0.05) greater ToG, ΔHG, and PHI but a significantly lower RG than those from Puerto Rico (1990–1991). These data suggest that the starch from plants grown in Georgia (1994) might have a greater degree of crystallinity than that from Puerto Rico (1990–1991). None of the retrogradation values were significantly different among starches of the 62 lines of Antigua 1 and the starches from plants grown in the two locations.
Modeling Cereal Grain Drying with Variable Diffusivity
Authors: Tolaba Marcela P. , Aguerre Roberto J. , Suárez Constantino 
Published: June 2007

ABSTRACTThe thin‐layer drying or rough rice, maize and sorghum at several temperatures was investigated. Simulation of the experimental data was performed by solving numerically the diffusion equation with variable diffusion coefficient for spherical‐shaped grain. To account for this variation, an analytical expression for the dependence of the diffusion coefficient with moisture content was obtained based on considerations of the energy needed to dissociate water molecules from their sites and of resistance to diffusion. When the expression for diffusivity was used for predicting drying behavior of the grains, a good agreement was obtained between experimental data and the theoretical prediction.
Proteins as Agricultural Polymers for Packaging Production
Authors: Cuq Bernard , Gontard Nathalie , Guilbert Stéphane 
Published: June 2007

ABSTRACTAdvantages, types, formation, and properties of agricultural packaging materials based on proteins, with examples, are reviewed in detail. Proteins have long and empirically been used to make biodegradable, renewable, and edible packaging materials. Numerous cereal and vegetable proteins (such as corn zein, wheat gluten, and soy proteins) and animal proteins (such as milk proteins, collagen, gelatin, keratin, and myofibrillar proteins) are commonly used to form agricultural packaging materials. Two technological processes have been investigated to make materials based on proteins: the “wet (or solvent) process” based on dispersion or solubilization of proteins in a solvent medium, and the “dry process” based on the thermoplastic properties of proteins under low water content conditions. The macroscopic properties (including solubility in water, mechanical properties, and barrier properties) of agricultural packaging materials based on proteins are dependent mainly on the structure of the macromolecular three‐dimensional network and on interactions between proteins, plasticizers, and cross‐linking agents.
Effects of Blend and Processing Method on the Nutritional Quality of Weaning Foods Made from Select Cereals and Legumes
Authors: Griffith L. D. , Castell‐Perez M. E. , Griffith M. E. 
Published: June 2007

ABSTRACTWeaning blends, formulated in a 60% cereal to 40% legume combination using teff, pearl millet, cowpea, and peanut, were evaluated for changes in nutritional quality due to the effects of blend and processing method. Four blends were prepared by each of four traditional processing methods: control (unprocessed), roasting, germination, and natural fermentation. The main effect of blend formulation proved to be the stronger determinant of nutrient density, while processing method produced the strongest effect on weaning food viscosity. Germinated blends yielded viscosity measurements significantly below those resulting from other processing methods. Germination of ingredients increased nutrient density and in vitro protein digestibility, while roasting and fermentation produced little change from the control product. Complementation of cereal flours with peanut yielded weaning foods with a significantly (P < 0.01) higher nutrient density, increased in vitro protein digestibility and lower viscosity when compared to cowpea‐based blends. The use of 20% whole grain teff in weaning blends increased protein content but did not significantly increase nonstarch polysaccharide content as compared to weaning blends without teff.
Comparison of Pearled and Unpearled Canadian and Japanese Barleys
Authors: Bhatty R. S. , Rossnagel B. G. 
Published: June 2007

ABSTRACTCanadian and Japanese barleys were compared for whole and pearled grain composition and starch properties. Whole grain color and composition of the barleys showed large intercultivar differences, but few (color, protein, and total dietary fiber) significant differences between the Canadian and Japanese barleys. The Canadian hull‐less barleys (HB) were pearled to 55% yield to match pearl yields of Japanese barleys. In Canadian HB, pearl time was correlated (r2 = +0.96**) with grain hardness. There were large intercultivar differences in color and composition of the pearled barleys; only protein, starch, total dietary fiber, and viscosity showed significant differences between the Canadian and Japanese pearled barleys. Pasting properties of the four Canadian pearled barleys (CDC Candle, AC Hawkeye, Falcon, and CDC Richard) and three Japanese pearled barleys (Hinode, Ichiban‐Boshi, and Minori) showed Canadian pearled barleys had higher peak viscosity, viscosity at 95°C, and setback viscosity than the Japanese barleys. These differences in pasting properties were not related to amylose or crude lipid contents of Canadian and Japanese pearled barleys, nor to swelling factor and thermal properties of starches isolated from the barleys. They were likely due to higher β‐glucan and protein in starch slurries of Canadian HB.
Effect of Conditioning Agents on the Structure of Tempered and Steam‐Flaked Sorghum
Authors: McDonough C. , Anderson B. J. , Acosta‐Zuleta H. , Rooney L. W. 
Published: June 2007

ABSTRACTTempering agents affect the pericarp of steamed grain and the endosperm of steam‐flaked sorghum. Examination by environmental scanning electron microscopy (ESEM) clearly showed that β‐mercaptoethanol (BME), sulfurous acid (SA), phosphoric acid, and cellulase significantly altered the structure of the pericarp and endosperm during tempering. Lime and protease had a lesser effect on the pericarp structure of the kernels, and had little effect on the endosperm. Steamed flakes from the SA treatment were more translucent and durable than all other treatments. Flakes with BME were translucent and high in quality, but were more fragile than the SA flakes. Nontempered, water only, and commercial conditioner treatments produced flakes with the lowest quality. Peak, final, and breakdown Rapid Visco Analyzer (RVA) viscosities were lowest for the SA flakes due to disruption of the starch chains by the weak acid. BME viscosity values were higher than SA, but lower than the water and commercial tempering treatments. The commercial conditioner (15×normal concentration) did not alter kernel structure and did not cause any changes in the RVA profiles over kernels tempered with water alone. Starch gelatinization, measured by enzyme susceptible starch (ESS), was highest in the SA and BME flakes and lowest in the nontempered flakes. Feedlot operators may be able to save money by avoiding the use of chemical additives that do nothing to the grain. By using chemicals proven to have positive effects on flake quality, operators could save money by reducing the processing time and energy needed to produce good quality flakes.
Surface Derivatization of Corn Starch Granules
Authors: Whistler Roy L. , Madson Michael A. , Zhao Jingan , Daniel James R. 
Published: June 2007

ABSTRACTCommercial corn starch, treated with stearoyl chloride in carbon tetrachloride and triethylamine, is surface‐derivatized without noticeable swelling. Granules that are reacted with chloroacetic acid under similar conditions undergo surface etherification, visibly identified by their color binding with fuchsin. Interestingly, the dye experiment indicates surface‐derivatization as well as derivatization of the granule central interior, suggesting reagent penetration to the granule interior through pores and derivatization of a lower density porous center. Esterification of corn starch granules treated with glucoamylase have five times greater esterification than normal corn starch granules. Placed in water, these and palmitoylated granules have a fatty feel to the fingers. Stearoylated corn and amaranth starches showed indications for use as fat replacers in frozen desserts.
Stress Relaxation and Oscillatory Tests to Distinguish Between Doughs Prepared from Wheat Flours of Different Varietal Origin
Authors: Safari‐Ardi Mohsen , Phan‐Thien Nhan 
Published: June 2007

ABSTRACTThe relaxation properties of flour‐water‐salt doughs prepared from four different flour types (weak, medium, strong, and extra strong) at different water absorption levels from 58 to 66% with protein contents of 10.0, 10.9, 13.2, and 11.8%, respectively, were studied by imposing varying strain amplitudes of 0.1–29%. Oscillatory tests in the linear viscoelastic region of the 66% absorption strong and weak dough cannot distinguish between the two types of dough. The inability to differentiate between dough types also applied to oscillatory tests on 58% absorption weak and 66% absorption strong doughs. However, the relaxation modulus of dough (extending over time) behaved quite distinctively at high strains, where dough samples experience large deformations. At strain amplitudes of ≤0.1% (i.e., in the linear viscoelastic region), different dough types behaved similarly. Likewise, the relaxation modulus completely relaxed at sufficiently long times. The magnitude of the modulus at intermediate‐ and high‐strain amplitudes were in the order: extra strong > strong > medium > weak, indicating a higher level of elasticity in the extra strong dough samples despite its lower protein content. The relaxation times spectrum of the weak flour, extracted from the relaxation modulus data, reveals a broad relaxation process. The stress relaxation data are very reproducible at high‐strain amplitudes (≈1–15% for up to 3 × 103 sec). This work demonstrated, for the first time, the consistency in oscillatory and relaxation measurements for dough. It also clearly showed that linear viscoelastic data, although important in the characterization of time scales in dough, are largely irrelevant in differentiating between dough types. Furthermore, without proper care, a false steady‐state behavior can be obtained with standard viscometric measurements due to slippage at the dough‐plate interface.
Water Vapor Barrier Properties of Zein Films Plasticized with Oleic Acid
Authors: Lai Huey‐Min , Padua Graciela W. 
Published: June 2007

ABSTRACTWater sorption, water vapor permeability, and tensile properties were evaluated for zein films plasticized with oleic acid. The effect of relative humidity on water vapor permeability and tensile properties of films was investigated. Samples were produced by two different methods: casting from a zein solution and stretching from a zein‐fatty acid resin. Films were also coated with linseed oil. Results indicated that preparation method affected water sorption and permeability of zein films. Resin films showed lower water sorption than cast films, especially at high Aw values. Water vapor permeability was also lower for resin films. Coating with linseed oil further improved water vapor barrier ability of resin films. Permeability was affected by environmental relative humidity; higher relative humidity resulted in increased permeability. Environmental relative humidity also affected tensile properties of resin films. Toughness and elongation were improved when relative humidity increased from 50 to 85% rh. Tensile strength showed a maximum at 75% rh. Coating improved elongation and toughness of films. Maximum elongation and toughness were observed for coated samples at 85% rh. Zein resin films showed good tensile and water barrier properties that were maintained through environmental humidity levels from 50 to 98% rh.
Assay of Dehydroascorbic Acid in Bread and Dough Added as a Crystalline Dimer
Authors: Lu Xiuzhen , Seib Paul A. 
Published: June 2007

ABSTRACTThe assay of dehydro‐l‐ascorbic acid (DHAA) in dough and bread was done by reduction of DHAA to l‐ascorbic acid (AA) in aqueous dithiothreitol (DTT) at pH 6–7 followed by quantitation of the AA using HPLC with electrochemical detection. At room temperature and pH 6.6, with 4.0 equivalents of DTT, the conversion of DHAA to AA was stoichiometric after 5 min. In mixograms on flour‐water doughs, DHAA added in dimeric form at 200 ppm had no effect on absorption but increased mixing time by 9–19% with the same effects occurring in full‐formula doughs. AA added to doughs did not affect mixing peak time or absorption. Mixing bread doughs with an initial level of 25–200 ppm of AA based on flour (14% mb) produced DHAA in the freshly mixed doughs at concentrations of 20–51 ppm, or from 80 to 26% of AA added. During ≈120 min of fermentation and proofing, the levels of AA in the doughs increased by 4–10 ppm. Mixing bread doughs with an initial level of 25–200 ppm of DHAA produced no AA in the freshly mixed doughs, but the proofed doughs and fresh breads contained 4–10 ppm and 7–49 ppm of AA, respectively. Fresh bread made from dough with 200 ppm of AA retained 66% total vitamin C (110 ppm of AA + 21 ppm of DHAA), whereas bread made with 200 ppm of DHAA retained 9.5% total vitamin C (13 ppm of AA + 6 ppm of DHAA). DHAA was 2–4 times more effective in improving loaf volume than an equal weight of AA in no‐time dough, and 1.5–2 times more effective in straight‐dough. In straight‐dough bread made with a commercial bread flour, increasing concentrations of DHAA markedly improved bread up to ≈20 ppm, beyond which overoxidation occurred rapidly. In contrast, increasing concentrations of AA improved bread up to ≈150 ppm with a broad tolerance up to 200 ppm. The improving action of DHAA was independent of the concentration of air in the mixing bowl, and DHAA was much more heat‐labile than AA.
Use of Aspiration and the Single Kernel Characterization System to Evaluate the Puffed and Shriveled Condition of Soft Wheat Grain
Authors: Gaines C. S. , Finney P. L. , Fleege L. M. , Andrews L. C. 
Published: June 2007

ABSTRACTShriveled kernels lower wheat test weight and reduce milling flour yields. Test weight is also lowered by rain‐dry cycles that cause kernels to puff (exhibit, in part, loosened layers of pericarp). A numeric score was developed for degree of puffing and for degree of shriveling based on simple measurement devices. Wheat samples were evaluated for test weight and Single Kernel Characterization System (SKCS) hardness index, SKCS kernel weight, milling flour yield, and kernel density (hexane displacement). Those evaluations were performed before and after samples were air‐aspirated to remove all shriveled kernels. Test weight, SKCS hardness index, and density of aspirated samples were used to develop a puffing score. Changes (resulting from aspiration) in test weight, SKCS kernel weight, and flour yield were used to develop a shriveling score. Higher puffing scores were related to elevated α‐amylase activity. Puffed kernels were softer and were not associated with decreased flour yield. Puffing and shriveling scores were independent (poorly correlated), but together predicted 95% of the variation in original, nonaspirated test weight.
Changes Occurring in Protein Body Structure and α‐Zein During Cornflake Processing
Authors: Batterman‐Azcona Sheri J. , Hamaker Bruce R. 
Published: June 2007

ABSTRACTZeins, which comprise the majority of proteins in corn, are located in spherical organelles called protein bodies. Changes in protein body shape and release of encapsulated α‐zeins as a result of cornflake processing (conventional pressed or extrusion flaking) were investigated. Size‐exclusion chromatography, SDS‐PAGE, and protein solubility tests showed that, upon cooking, zein proteins form large, disulfide‐bound polymers, many of which were insoluble in nonreducing solvents. Transmission electron microscopy with immunogold staining revealed that cooking had no effect on protein body structure in corn, but after processing to cornflakes, protein body structure was altered. In conventional pressed cornflakes, the protein bodies were flattened, partially fused together, and α‐zeins were to some degree released, whereas in the extruded flakes, protein bodies were completely disrupted and α‐zeins dispersed. These results suggest that zeins in cornflakes, particularly extruded ones, are not confined to rigid protein bodies but can interact with each other and other components in the system. The disruption of protein bodies, zein release, and the chemical changes that proteins undergo during processing are speculated to be determinants of texture in ready‐to‐eat corn‐based breakfast cereals.
Wet‐Milling Characteristics of Selected Yellow Dent Corn Hybrids as Influenced by Storage Conditions
Authors: Singh V. , Haken A. E. , Niu Y. X. , Zou S. H. , Eckhoff S. R. 
Published: June 2007

ABSTRACTThree yellow dent corn hybrids (FR1064×LH59, FR600×FR1087, and FR618×LH123HT) from the 1994 crop, one hybrid (FR1064×LH59) from the 1995 crop, and two hybrids (FR1064×LH59 and FR618×LH123HT) from the 1996 crop were used to study the effect of storage time and storage temperature on starch yields. Samples of all of the corn hybrids were stored under one of two conditions: in a 4°C cold room or under a shed exposed to ambient conditions. The hybrids from the 1994, 1995, and 1996 crops were stored for up to 24, 12, and 3 months, respectively. No significant differences were found between starch yields of the hybrids with respect to storage time. However, there was a significant difference in hybrids from the 1994 samples. Starch yields of two of the three corn hybrids (from the 1994 crop) stored in the 4°C cold room were higher when compared to the starch yields of the same hybrids stored at ambient conditions.