bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extrusion Chemistry of Wheat Flour Proteins: I. Free Radical Formation
Authors: Schaich K. M. , Rebello C. A. 
Published: June 2007

ABSTRACTElectron paramagnetic resonance (EPR) spectroscopy was used to study free radical production in hard red wheat flours extruded according to a two‐level fractional factorial experimental design (11 and 14% protein content, 160 and 185°C, 16 and 20% moisture, 300 and 500 rpm screw speed, and mass flow rate of 225 and 400 g/min). All spectra showed dominant broad singlets (g = 2.0053–2.0059) from nitrogen‐centered radicals originating from heat‐induced peptide scission and reactions of lipid radicals with side‐chain amino groups. At 77 K, sulfur‐oxyl or peroxyl radicals (g = 2.008–2.018), thiyl radicals (g = 2.025), and disulfide radical species (g = 2.032–2.035 and 2.05–2.06), resulting from intra‐ and intermolecular electron migration and shear‐induced scission of disulfides, sometimes were present. The strongest EPR signals occurred under conditions of maximum free radical production and minimum opportunity for radical recombination: high protein flour (14%), high die temperature (180°C), and low moisture (16%). EPR signals correlated with sulfhydryl and disulfide (SH‐SS) levels and physical properties of extrudates, indicating that free radicals are integrally involved in molecular changes that occur during extrusion.
Effect of Chemical Pretreatments and Lactic Acid on the Rate of Water Absorption and Starch Yield in Corn Wet‐Milling
Authors: Haros M. , Suárez C. 
Published: June 2007

ABSTRACTThe relative effectiveness of dehulling, potassium hydroxide dipping (alkali concentrations 0.2, 0.5, and 1.0 %), and ethyl oleate spraying (aqueous emulsion 1%, v/v) to increase the rate of water absorption by dent and flint corn during steeping was compared with untreated corn samples. These pretreatments increased the water absorption rate of both hybrids when compared with the untreated control samples. To evaluate the observed increase, the diffusion coefficients of pretreated and untreated corn samples were estimated. Corn grains steeped in SO2 aqueous solution and variable lactic acid concentrations (0.2, 0.5, and 1.0%, v/v) were performed. Absorption rates for lactic acid concentrations were ≈0.5% higher than those steeped only in SO2 solution. This effect was more marked for dent than for flint corn. Corn samples pretreated with potassium hydroxide had lower starch yields than the control. However, the presence of lactic acid in steepwater increased the starch yield of dent and flint corn, particularly for the samples treated with alkaline solution. This procedure was particularly beneficial for flint corn. An effective release of the starch granules was achieved within 24 hr of steeping.
Effects of Wheat Starch and Gluten on Tortilla Texture
Authors: Wang Linfeng , Flores Rolando A. 
Published: June 2007

ABSTRACTWheat starches were isolated from three wheat flours. Two vital wheat glutens, one from a commercial source and another one isolated from straight‐grade flour, were combined with wheat starches to form reconstituted flours with a protein level of 10%. Several characteristics of tortillas made with the hot‐press method were measured. No significant difference (P < 0.05) occurred in texture of tortillas made with hard wheat gluten and soft wheat gluten. Wheat starches did not have any significant (P < 0.05) effect on tortilla stretchability or foldability. Analysis of variance confirmed that wheat starch and gluten had limited effects on tortilla texture. The possible reasons were that the solubles of wheat flour were not included, and the shortening in the tortilla formula interfered with the interaction of gluten and starch.
Effects of Wheat Bug (Eurygaster maura) Protease on Glutenin Proteins
Authors: Sivri D. , Sapirstein H. D. , Köksel H. , Bushuk W. 
Published: June 2007

ABSTRACTProteolytic degradation of 50% 1‐propanol insoluble (50PI) glutenin of six common wheat cultivars by wheat bug (Eurygaster maura) protease was investigated using reversed‐phase HPLC. Wheat at the milk‐ripe stage was manually infested with adult bugs. After harvest, bug‐damaged kernels were blended (2:1, kernel basis) with undamaged grain of the same cultivar. Samples of ground wheat were incubated in distilled water for different times (0, 30, 60, and 120 min). The incubated whole meal samples were subsequently freeze‐dried and stored until analysis. The degree of proteolytic degradation of 50PI glutenin was determined based on the quantity of total glutenin subunits (GS), high molecular weight GS (HMW‐GS), and low molecular weight GS (LMW‐GS). For ground wheat samples incubated for ≥30 min, 50PI glutenin was substantially degraded as evidenced by a >80% decrease on average in total GS, HMW‐GS, and LMW‐GS. Some cultivars showed different patterns of glutenin proteolysis as revealed by differences in the ratios of HMW‐GS to LMW‐GS between sound and bug‐damaged samples; a significant decrease in this ratio was found for four cultivars. This evidence, combined with other observations, indicated that there were intercultivar differences in polymeric glutenin resistance to the protease of the wheat bug Eurygaster maura. While the nature of this resistance is unknown, it should be possible to select and develop wheat cultivars with improved tolerance for wheat bug damage. Propanol insoluble glutenin, which corresponds to relatively large glutenin polymers, appears to be an excellent quantitative marker for this purpose.
Potential Use of Raman Spectroscopy for Determination of Amylose Content in Maize Starch
Authors: Lee Phillips David , Xing Jie , Liu Huijun , Pan Duo‐Hai , Corke Harold 
Published: June 2007

ABSTRACTAn analytical method using Raman spectroscopy was developed for the determination of amylose concentration in maize starches. FT‐Raman spectra of four maize starches with amylose content varying from 3.3 to 66% were obtained. A Raman band at ≈1657 cm‐1 correlated linearly with amylose concentration in the four maize starches, and a calibration curve for Raman band intensity versus amylose content was developed. The linear correlation of the I1657/I900 integrated areas with amylose content was r = 0.997. The Raman‐based calibration curve allows fast and nondestructive determination of the amylose content in maize starches with minimal sample preparation.
Effect of Corn Oil on Thin Stillage Evaporators
Authors: Singh V. , Panchal C. B. , Eckhoff S. R. 
Published: June 2007

ABSTRACTRemoval of the germ at the front end of the dry‐grind ethanol process using the Quick Germ process reduces the amount of oil in thin stillage. Thin stillage with 4–6% solids is dewatered to 25–30% solids by evaporation. Thin stillage evaporators in a dry‐grind ethanol plant foul and have to be periodically taken down for maintenance and cleaning. Fouling caused by thin stillage containing different amounts of oil was studied using an annular fouling probe. It was determined that the rate of fouling in a drygrind ethanol plant is three times higher when compared with that in a wet‐milling ethanol plant. The addition of oil to wet‐milled thin stillage significantly affected the rate of fouling. Fouling resistance increased with an increase in oil concentration for wet‐milled thin stillage up to a concentration of 1.41%. At a concentration of 1.47%, the rate of fouling decreased. As the concentration of oil increased in dry‐grind ethanol thin stillage, the rate of fouling decreased. These results suggest that the Quick Germ process will reduce the rate of heat transfer equipment fouling in a drygrind ethanol plant, which will decease capital costs and maintenance costs.
Segregating Hard Red Winter Wheat into Dough Factor Groups Using Single Kernel Measurements and Whole Grain Protein Analysis
Authors: Baker Scott , Herrman Timothy J. , Loughin Thomas 
Published: June 2007

ABSTRACTIn accordance with the Grain Quality Acts of 1986 and 1990, scientists at Kansas State University are studying the feasibility of implementing a quality‐based marketing system for hard red winter (HRW) wheat in the Southern Plains. This research addresses the development of a segregation system that uses the single kernel characterization system and the whole grain near‐infrared analyzer to evaluate the milling and baking quality of wheat as a single value called “dough factor”. This single value represents the amount of flour‐water dough that can be produced from a given unit of wheat. Samples of HRW wheat (≈100 per location) were collected at five Kansas country elevators during the 1995 and 1996 harvests. After the dough factor was measured for individual samples, the samples were composited into seven dough factor groups to establish binning and segregation strategies and to explore the relationship between wheat quality measurements and dough factor groups. Results showed that dough factor groups were significantly different from each other and that dough factor groups were related (P < 0.05) to increases in test weight, single kernel weight, single kernel size, flour yield, and mixing time. Although locations showed year‐to‐year variability for test weight, kernel weight, and kernel size, the differences among dough factor groups for these characteristics across locations were consistent, indicating that the mean values within dough factor groups are similar regardless of location. The lack of significant differences in protein content among dough factor groups was attributable to high variability within dough factor groups between years. High protein values were present in low and high dough factor groups, indicating that protein content alone is not a good indicator of wheat quality. Patterns of differences in wheat quality characteristics among dough factor groups suggest that the seven groups studied can be reduced to three groups: <107, 107–112.9, ≥113. This study demonstrates that dough factor as a segregation and marketing tool is related to single kernel characteristics, differentiates wheats of varying quality, and reflects the end‐use value of wheat.
Optimizing the SDS Sedimentation Test for End‐Use Quality Selection in a Soft White and Club Wheat Breeding Program
Authors: Carter Brady P. , Morris Craig F. , Anderson James A. 
Published: June 2007

ABSTRACTSoft white and club wheat (Triticum aestivum L.) market subclasses have specific end‐use characteristics. Among the most important of these characteristics are weak dough mixing and handling properties as a result of weak gluten. The SDS sedimentation test has gained wide acceptance as a useful, small‐scale test in bread wheat breeding programs to predict gluten strength and baking quality. To optimize its use for soft white or club wheat breeding, variations of the SDS sedimentation test were performed on grain from winter wheats grown at eight locations in the U.S. Pacific Northwest, and the effects of lines, environment, and their interactions on SDS sedimentation volumes were determined. Using different sample weights and substituting whole meal for flour did not affect the ability of the SDS sedimentation test to differentiate among lines. Changes in protein concentration and sample weight caused proportional changes in SDS sedimentation volumes; however, the response was not consistent among all lines. Line had a greater effect on the SDS sedimentation volumes than any other source of variation. If differential effects of protein to SDS sedimentation among lines are taken into account, the SDS sedimentation test should be an effective small‐scale test for end‐use quality assessment in soft white and club wheat breeding programs.
Role of Starch Granules in Controlling Expansion of Dough During Baking
Authors: Kusunose Chiharu , Fujii Toshiko , Matsumoto Hiroshi 
Published: June 2007

ABSTRACTThe role of starch granules in the expansion of doughs during baking was investigated using artificial flours made from dry vital wheat gluten and wheat starch, potato starch, or tapioca starch. The three starches were selected because of their diverse gelatinization properties. Baking tests on flour from tapioca starch gave the largest loaf volume and the most extensive postbaking shrinkage. Potato starch flour gave the smallest volume and the least shrinkage. Amylograph test data, dough expansion under decreased pressure, progress of expansion during baking, and scanning electron microscopy revealed the role starch granules play in ideal baking conditions. Starch granules should not gelatinize early in the baking cycle as potato starch does but should gelatinize later in the baking cycle as wheat starch does. This prevents early setting of the dough which inhibits expansion. Starch granules should not disrupt and fuse together during gelatinization as tapioca starch does, forming an impermeable gas membrane. Granules should gelatinize individually as wheat starch does, causing a disruption of cell membranes which prevents shrinkage of the loaf during cooling after baking.
α‐Amylolysis of Large Barley Starch Granules
Authors: Lauro M. , Forsell P. M. , Suortti M. T. , Hulleman S. H. D. , Poutanen K. S. 
Published: June 2007

ABSTRACTThe α‐amylolysis of large (volume average 16 μm) barley starch granules was studied by measuring the amount of carbohydrates solubilizing during hydrolysis, and the changes in morphology and molecular structure of the granule residues by scanning electron microscopy, particlesize analysis, size‐exclusion chromatography, X‐ray diffraction, and differential scanning calorimetry. X‐ray diffraction showed that, in the earlier stages of α‐amylolysis, both amorphous and crystalline parts of the granules were equally solubilized. More extensive hydrolysis caused a gradual decrease in A‐type crystallinity and degradation of the granular structure. Scanning electron microscopy revealed that hydrolysis proceeded through pinholes, and pitted and partially hollow granule residues were formed. The lipid‐complexed amylose was less susceptible to α‐amylolysis than free amylose and amylopectin. Lipid‐complexed amylose started leaching out of the granule residues only after half of the starch had solubilized due to the α‐amylase treatment. Even though scanning electron microscopy indicated that there were intact granules left throughout the hydrolysis, the results obtained suggested that α‐amylolysis of large barley starch granules proceeded rather evenly among the granules.
Physical Properties and Enzymatic Digestibility of Phosphorylated ae, wx, and Normal Maize Starch Prepared at Different pH Levels
Authors: Liu Huijun , Ramsden Lawrence , Corke Harold 
Published: June 2007

ABSTRACTPhosphorylated starches were prepared with sodium tripolyphosphate (STPP) at pH 6, 8, and 10 from waxy (wx, 3.3% amylose), normal (22.4% amylose), and two high‐amylose (ae, 47 and 66% amylose) maize starches. After phosphorylation, the gelatinization peak temperature (Tp) decreased and pasting peak viscosity (PV) increased for all the starches except wx, which showed a slight increase in gelatinization temperature. There was a substantial effect of phosphorylation pH on paste viscosity. More crosslinking was found in ae starches with phosphorylation at pH 10. Sodium ions apparently decreased PV of all the phosphorylated starches while only slightly affecting PV of native starches. Phosphorylation increased swelling power of some of the starches, with maximum swelling power at phosphorylation pH 8 and minimum at pH 10. Maximum swelling power for wx starch after preparation was at pH 8 and minimum at pH 6. After phosphorylation, the clarity and freeze‐thaw stability of all the starches was greatly increased compared with the native starches. Phosphorylation increased digestibility of ae starches but had little effect on wx and normal starches. After phosphorylation, the adhesiveness, springiness, and cohesiveness of all starch gels generally increased, the hardness of 47% ae and wx starches increased, and that of normal starches decreased. Enthalpy of gelatinization decreased after phosphorylation with the greatest decrease observed for ae starches. When the phosphorylation pH increased from 6 to 10, the brightness (L*) of all the phosphorylated starches decreased, while a* and b* of all the phosphorylated starch increased. Scanning electron micrographs showed some erosion on the surface of starch granules after phosphorylation.
Effect of Amylose Content on Gelatinization, Retrogradation, and Pasting Properties of Starches from Waxy and Nonwaxy Wheat and Their F1 Seeds
Authors: Sasaki Tomoko , Yasui Takeshi , Matsuki Junko 
Published: June 2007

ABSTRACTWe studied the effect of amylose content on the gelatinization, retrogradation, and pasting properties of starch using wheat starches differing in amylose content. Starches were isolated from waxy and nonwaxy wheat and reciprocal F1 seeds by crossing waxy and nonwaxy wheat. Mixing waxy and nonwaxy wheat starch produced a mixed starch with the same amylose content as F1 seeds for comparison. The amylose content of F1 seeds ranged between waxy and nonwaxy wheat. Nonwaxy‐waxy wheat had a higher amylose content than waxy‐nonwaxy wheat. Endothermic enthalpy and final gelatinization temperature measured by differential scanning calorimetry correlated negatively with amylose content. Gelatinization onset and peak temperature clearly differed between F1 and mixed starches with the same amylose content as F1 starches. Enthalpy for melting recrystallized starches correlated negatively with amylose content. Rapid Visco Analyser measurement showed that F1 starches had a higher peak viscosity than waxy and nonwaxy wheat starches. Mixed starches showed characteristic profiles with two low peaks. Setback and final viscosity correlated highly with amylose content. Some of gelatinization and pasting properties differed between F1 starches and mixed starches.
Oil Absorption Characteristics of a Multigrain Extrudate During Frying: Effect of Extrusion Temperature and Screw Speed
Authors: Osman M. G. , Sahai D. , Jackson D. S. 
Published: June 2007

ABSTRACTThe oil absorption characteristics of a multigrain extruded and fried snack product were studied as a function of extruder screw speed and cooking temperature using a central composite response surface methodology (RSM). The extruded product was produced using a corotating twin screw extruder, dehydrated to a uniform moisture content, and subsequently deep‐fat‐fried at 192 ± 1°C for 10–40 sec to complete expansion. Significant RSM models were developed for oil absorption and extrudate water absorption index (WAI). According to the lowest oil model, absorption (19.9%) was obtained with an extruder screw speed of 218.6 rpm and a cooking temperature of 117.8°C. WAI reached a maximum at a screw speed of 221.9 rpm and a cooking temperature of 109°C. Oil absorption characteristics and extrudate WAI were significantly correlated (r= ‐0.84, P = 0.0002). The data suggest that extrusion conditions can be optimized to influence the physicochemical structures in the extrudate matrix so that oil absorption can be minimized.
Composition and Utilization of Barley Pearling By‐Products for Making Functional Pastas Rich in Dietary Fiber and β‐Glucans
Authors: Marconi E. , Graziano M. , Cubadda R. 
Published: June 2007

ABSTRACTPearling by‐products and the pearled products of two commercial stocks of hulled barley, pearled according to an industrial process consisting of five consecutive pearling steps, were analyzed for β‐glucans, dietary fiber (total, soluble, and insoluble), protein, lipid, ash, and digestible carbohydrate. The data showed that the pearling flour fractions, abraded in the fourth and fifth hullers, contained interesting amounts of β‐glucans (3.9–5.1% db) from a nutritional point of view. These fractions were subsequently enriched in β‐glucans using a milling‐sieving process to double β‐glucan content (9.1–10.5% db). Functional pastas, enriched with β‐glucans and dietary fiber, were produced by substituting 50% of standard durum wheat semolina with β‐glucan‐enriched barley flour fractions. Although darker than durum wheat pasta, these pastas had good cooking qualities with regard to stickiness, bulkiness, firmness, and total organic matter released in rinsing water. The dietary fiber (13.1–16.1% wb) and β‐glucan (4.3–5.0% wb) contents in the barley pastas were much higher than in the control (4.0 and 0.3% wb, respectively). These values amply meet the FDA requirements of 5 g of dietary fiber and 0.75 g of β‐glucans per serving (56 g in the United States and 80 g in Italy). At present, the FDA has authorized the health claim “may reduce the risk of heart disease” for food containing β‐glucans from oat and psyllium only.
Distribution of β‐Glucan in the Grain of Hull‐less Barley
Authors: Zheng G. H. , Rossnagel B. G. , Tyler R. T. , Bhatty R. S. 
Published: June 2007

ABSTRACTNine hull‐less barley (HB) containing waxy (0–7% amylose), normal (≈25% amylose), or high amylose (≈42% amylose) starch with normal or fractured granule make‐up and 4–9% (1→3)(1→4)‐β‐d‐glucans (β‐glucan) were pearled to remove 70% of the original grain weight in 10% intervals. The pearled fractions were analyzed for β‐glucan distribution within HB grain. Protein content of the pearled fractions indicated that the three outermost fractions contained pericarp and testa, aleurone, and subaleurone tissues, respectively. For all HB, β‐glucan and acid‐extract viscosity were very low in the outermost 20% of the kernel. For low β‐glucan HB, β‐glucan content was the greatest in the subaleurone region and declined slightly toward inner layers. For high β‐glucan HB, however, more than 80% of grain β‐glucan was distributed more evenly throughout the endosperm. Acid extract viscosity was significantly (P < 0.01) correlated with total (r = 0.75) and soluble (r = 0.87) β‐glucan content throughout the kernel of all HB. Growing conditions, location and year, had significant effects on the concentration of protein, starch and β‐glucan. However, protein, starch, and β‐glucan distribution patterns were not affected by growing conditions. The difference in β‐glucan distribution between low and high β‐glucan HB may explain the difference in milling performance of HB with low or high β‐glucan.
Genotypic and Environmental Effects on Oat Milling Characteristics and Groat Hardness
Authors: Doehlert Douglas C. , McMullen Michael S. 
Published: June 2007

ABSTRACTThe production of oat bran involves the dehulling of oats, inactivation of their enzymes, and the subsequent grinding and sieving of the clean groats to isolate the larger bran particles. The bran yield from the oat groats may be related to their hardness, as it is in wheat. Groat breakage, which occurs during the dehulling process, reduces milling yield and may also be related to groat hardness. This study sought to investigate genotypic and environmental effects on oat dry milling and oat dehulling characteristics, and attempted to define properties associated with oat groat hardness. Significant genotypic differences in bran yield were largely attributed to groat composition, where higher β‐glucan and oil concentrations in the groat were associated with higher bran yields. Bran composition was largely dependent on a combination of the bran yield and the groat composition. Although groat breakage was correlated with bran yield and with groat β‐glucan concentration, environmental factors appeared to be more influential. Locations that had suffered severe crown rust infestations exhibited higher rates of groat breakage during dehulling. Bran yield was not as strongly affected at the locations infested with crown rust, indicating that bran yield and groat breakage are manifestations of different types of groat hardness and are only partially related.