bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteins Extracted from Defatted Wheat Germ: Nutritional and Structural Properties
Authors: Zhu Ke‐Xue , Zhou Hui‐Ming , Qian Hai‐Feng
Published: June 2007

The main by‐product of the wheat germ oil extraction process is a defatted wheat germ meal, which has a relatively high protein content, making it an attractive and promising source of vegetable proteins. Four protein fractions (albumin, globulin, prolamine, and glutelin) and protein isolate from defatted wheat germ flour (DWGF) were fractionated and then characterized by amino acid analysis, SDS‐PAGE, and differential scanning calorimetry (DSC). Albumin was the major fraction (34.5%) extracted, followed by globulin (15.6%), glutelin (10.6%), and prolamine (4.6%). Protein isolate was mainly composed of albumin and globulin. These protein fractions and protein isolate showed an excellent balance of all essential amino acids, with a relatively high level of glutamic acid, arginine, leucine, and glycine, whereas cystine was lacking. All the estimated nutritional quality parameters based on amino acids composition showed that defatted wheat germ proteins had good nutritional quality. Nonreduced and reduced SDS‐PAGE analyses showed that S‐S bonds ere deficient in the structure of wheat germ proteins. The albumin fraction consisted of 19 major polypeptide bands with Mr 14,000–84,000. The globulin fraction showed four distinct polypeptides or polypeptide group bands with Mr 55,000, 37,000–43,000, 24,000, and 12,000–20,000, which may be the components of the 8S‐type and 11S‐like proteins. The prolamine fraction showed a predominant doublet‐like band at Mr 17,000–16,000, while the glutelin fraction showed five major polypeptide bands with Mr 39,000, 20,000, 18,000, 17,000, and 14,000. Protein isolate and DWGF showed very similar SDS‐PAGE patterns. Except for prolamine and glutelin fractions without detectable calorimetric response, the globulin fraction possessed the highest thermal stability (Td = 83.80°C, ΔH =1.36 J/g ), followed by protein isolate (Td = 80.05°C, ΔH = 0.76 J/g), while the albumin fraction was lowest (Td = 69.72°C, ΔH = 0.53 J/g). The findings on defatted wheat germ proteins are important for their potential application as functional food ingredients.
Relationship Between Popcorn Composition and Expansion Volume and Discrimination of Corn Types by Using Zein Properties
Authors: Borras Francisco , Seetharaman Koushik , Yao Ni , Robutti Jose L. , Percibaldi Nora M. , Eyherabide Guillermo H.
Published: June 2007

The objective of this study was to determine the relationship between the amount and type of lipids, starch composition and structure, and storage proteins on popcorn expansion and to evaluate whether popcorns could be discriminated from other types of corn based on the protein elution parameters. Seven commercial Argentinean popcorn samples were used in the study and significant differences were observed in the popping volume of these popcorns. A significant negative correlation was observed between oleic acid and popping volume and a positive correlation was observed between linoleic acid and popping volume. Popcorn starch properties were significantly different from normal corn but no particular measured attribute of starch correlated with popping volume. α‐Zein proteins and glutelins significantly correlated with popcorn expansion volume with R2 = 0.963 and 0.744, respectively. The elution patterns of corn proteins could also be used to discriminate between different types of corn including popcorn, dent, and flint corns.
Ethanol Production from Pearl Millet Using Saccharomyces cerevisiae
Authors: Wu X. , Wang D. , Bean S. R. , Wilson J. P.
Published: June 2007

Four pearl millet genotypes were tested for their potential as raw material for fuel ethanol production in this study. Ethanol fermentation was performed both in flasks on a rotary shaker and in a 5‐L bioreactor using Saccharomyces cerevisiae (ATCC 24860). For rotary‐shaker fermentation, the final ethanol yields were 8.7–16.8% (v/v) at dry mass concentrations of 20–35%, and the ethanol fermentation efficiencies were 90.0–95.6%. Ethanol fermentation efficiency at 30% dry mass on a 5‐L bioreactor reached 94.2%, which was greater than that from fermentation in the rotary shaker (92.9%). Results showed that the fermentation efficiencies of pearl millets, on a starch basis, were comparable to those of corn and grain sorghum. Because pearl millets have greater protein and lipid contents, distillers dried grains with solubles (DDGS) from pearl millets also had greater protein content and energy levels than did DDGS from corn and grain sorghum. Therefore, pearl millets could be a potential feedstock for fuel ethanol production in areas too dry to grow corn and grain sorghum.
Extrusion Conditions Modify Hypocholesterolemic Properties of Wheat Bran Fed to Hamsters
Authors: Kahlon T. S. , de J. Berrios J. , Smith G. E. , Pan J. L.
Published: June 2007

Wheat bran was extruded in a twin‐screw extruder at five specific mechanical energy (SME) levels (0.120, 0.177, 0.234, 0.291, and 0.358 kWh/kg, dwb) and the cholesterol‐lowering effects were compared with those of unprocessed wheat bran when fed to four‐week‐old male golden Syrian hamsters (n = 10/treatment) for three weeks. Diets contained 10% total dietary fiber, 10.3% fat, 3% nitrogen, and 0.4% cholesterol. Plasma total cholesterol and very‐low‐density lipoprotein cholesterol were significantly lower with 0.120 kWh/kg extruded wheat bran diet compared with the unextruded wheat bran control. Total triglycerides were significantly lower with 0.120 and 0.177 kWh/kg wheat bran diets compared with those fed 0.291 and 0.358 kWh/kg extruded wheat bran diets. Cholesterol digestibility, total liver cholesterol, and total liver lipids were significantly lower with all the extruded wheat bran diets compared with the unextruded wheat bran control. Cholesterol digestibility for the 0.291 kWh/kg wheat bran diet was also significantly lower than all other extruded diets. Significantly more sterols were excreted with diets containing 0.291 and 0.358 kWh/kg extruded wheat bran compared with the unextruded wheat bran control. Wheat bran extruded with 0.291 kWh/kg diet resulted in a 13% reduction in plasma cholesterol and a 29% reduction in low‐density lipoprotein cholesterol. Considering lowest cholesterol digestibility, significantly higher sterol excretion, desirable plasma lipo‐protein cholesterol profile, significantly lower liver weight, total liver lipids, and liver cholesterol, the wheat bran extruded at 0.291 kWh/kg appeared to have the most desirable healthful potential. Data suggest that cholesterol‐lowering potential of wheat bran could be enhanced by optimizing the energy input used in the extrusion process.
Effect of Added Asparagine and Glycine on Acrylamide Content in Yeast‐Leavened Bread
Authors: Fink Martin , Andersson Roger , Rosén Johan , Åman Per
Published: June 2007

Effect of added asparagine and glycine on acrylamide content in yeast‐leavened bread was studied in a designed experiment. Added asparagine strongly increased acrylamide content in the breads, while added glycine decreased the content. The more asparagine in the dough, the stronger was the reducing effect of glycine. When glycine was applied on the surface of the fermented dough, there was also a significant reduction of acrylamide content in the bread. Addition of glycine but not asparagine caused an increased browning reaction during baking.
Brewing Performance of Malted Lipoxygenase‐1 Null Barley and Effect on the Flavor Stability of Beer
Authors: Hirota N. , Kuroda H. , Takoi K. , Kaneko T. , Kaneda H. , Yoshida I. , Takashio M. , Ito K. , Takeda K.
Published: June 2007

We examined the malting and brewing performances of a lipoxygenase‐1 (LOX‐1) null line of barley (Hordeum vulgare L.). The LOX‐normal malt and the LOX‐null malt were prepared from F4 populations derived from a single cross. We could not observe any major differences in the general malt characteristics between the two malts. A brewing trial was performed using these malts. The analysis of the wort and beer revealed that the absence of LOX‐1 had little effect on the general characteristics of the wort and beer. In contrast, beer made from the LOX‐null malt showed reduced levels of beer‐deteriorating substances, trans‐2‐nonenal (T2N), and trihydroxyoctadecenoic acid (THOD). In the sensory evaluation, well‐trained panel members recognized the significant superiority of the aged LOX‐null beer in terms of staleness. These results show that the LOX‐1 null barley line can be effectively used to improve the flavor stability of beer without changing the other important beer qualities.
Fortification of Bread with Hulls and Cotyledon Fibers Isolated from Peas, Lentils, and Chickpeas
Authors: Dalgetty David D. , Baik Byung‐Kee
Published: June 2007

Bread was prepared from wheat flour and wheat flour fortified with either 3, 5, and 7% legume hulls or insoluble cotyledon fibers, or with 1, 3, and 5% soluble cotyledon fibers isolated from pea, lentil, and chickpea flours. Incorporation of hulls or insoluble fibers resulted in increases in dough water absorption by 2–16% and increases in mixing time of dough by 22–147 sec. Addition of soluble fiber resulted in decreases in water absorption as the substitution rate increased and similar mixing times to the control dough. Loaf weights of breads containing hulls or insoluble fibers were generally higher than that of control bread at 149.4–166.5 g. However, the loaf volume of breads fortified with legume hulls and fibers (685–1,010 mL) was lower than that of the control bread (1,021 mL). Breads containing soluble fibers were more attractive in terms of crumb uniformity and color than breads containing either hulls or insoluble fibers. Breads fortified with legume hulls and fibers were higher in moisture content than control bread regardless of the type, source, or fortification rate. Bread fortified with up to 7% hulls or insoluble cotyledon fibers or up to 3% soluble cotyledon fibers, with the exception of 7% insoluble pea fiber, exhibited similar firmness after seven days of storage compared with the control bread, despite their smaller loaf volume. Breads containing hull fibers exhibited the lowest starch transition enthalpies as determined by DSC after seven days of storage, while the starch transition enthalpies of breads containing added soluble or insoluble fiber were not significantly different from the control bread.
Evidence that Minor Sprout Damage Can Lead to Significant Reductions in Gluten Strength of Winter Wheats
Authors: Barbeau William E. , Griffey Carl A. , Yan Zhihong
Published: June 2007

Seventeen winter wheat lines were grown in triplicate plots at Warsaw, Painter, and Blacksburg, VA, during the 1999–2000 growing season. Hagberg falling numbers, protein content, farinograms, sedimentation volumes, and total glutenin content were determined for flours derived from 153 harvested wheat samples. Over three inches (8.2 cm) of rain fell during the week before harvest in Blacksburg, resulting in falling numbers of 100 for Recital and 137 for Heyne, two severely sprouted Blacksburg wheat samples, and falling numbers <250 in three other Blacksburg wheats. There were no significant differences across locations in falling numbers of four wheat lines, and one line had significantly greater falling numbers in Blacksburg than in Warsaw or Painter. All 18 Blacksburg flours had a significantly higher mixing tolerance index (MTI) and shorter departure times (DT) than corresponding Warsaw flours. Weaker gluten strength of Blacksburg flours suggestss that all 18 Blacksburg wheats were sprout‐damaged and contained active proteases. However, according to falling number data, five of these Blacksburg wheats were sprout‐free with falling numbers >400. These data indicate that Hagberg falling number should not be used as the sole criteria for determining the degree of sprout damage in wheat because it does not quantify, nor always accurately reflect changes in protein composition and quality due to grain weathering.
Effect of pH on Fouling Characteristics and Deposit Compositions in Dry‐Grind Thin Stillage
Authors: Wilkins M. R. , Singh V. , Belyea R. L. , Buriak P. , Wallig M. A. , Tumbleson M. E. , Rausch K. D.
Published: June 2007

Dry‐grind corn processing facilities produce ethanol, carbon dioxide, and distillers dried grains with solubles (DDGS). To produce DDGS, dry‐grind corn processors concentrate thin stillage in multieffect evaporators. Concentration of thin stillage uses large amounts of energy, and efficient operation is important for long‐term economic stability of the industry. Little data are available on fouling of evaporators during thin stillage concentration. We evaluated how thin stillage pH and acid type used during pH adjustment affected fouling as measured by induction period, fouling rate, and deposit composition. Using an annular fouling apparatus, fouling tests were conducted at pH 3.5, 4.0, and 4.5. In a second experiment, we used two types of acid, HCl or H2SO4, to adjust thin stillage to pH 3.5. Induction periods were shorter at pH 3.5 than at pH 4.0 or 4.5. As pH increased, fouling deposit protein decreased and ash increased. Concentrations of most elements, including P, Ca, Mg, Mn, and K, increased with an increase in pH. Phosphorus was the most abundant mineral element in fouling deposits. Induction periods were similar for the two acids. Thin stillage pH has an influence on deposit concentration, fouling rate, and induction period.
Dry‐Grind Processing of Corn with Endogenous Liquefaction Enzymes
Authors: Singh Vijay , Batie Christopher J. , Aux George W. , Rausch Kent D. , Miller Carl
Published: June 2007

An amylase corn has been developed that produces an α‐amylase enzyme that is activated in the presence of water at elevated temperatures (>70°C). Amylase corn in the dry‐grind process was evaluated and compared with the performance of exogenous amylases used in dry‐grind processing. Amylase corn (1–10% by weight) was added to dent corn (of the same genetic background as the amylase corn) as treatments and resulting samples were evaluated for dry‐grind ethanol fermentation using 150‐g and 3‐kg laboratory procedures. Ethanol concentrations during fermentation were compared with the control treatment (0% amylase corn addition or 100% dent corn) which was processed with a conventional amount of exogenous α‐amylase enzymes used in the dry‐grind corn process. The 1% amylase corn treatment (adding 1% amylase corn to dent corn) was sufficient to liquefy starch into dextrins. Following fermentation, ethanol concentrations from the 1% amylase corn treatment were similar to that of the control. Peak and breakdown viscosities of liquefied slurries for all amylase corn treatments were significantly higher than the control treatment. In contrast, final viscosities of liquefied slurries for all amylase corn treatments were lower than those of the control. Protein, fat, ash, and crude fiber contents of DDGS samples from the 3% amylase corn treatment and control were similar.
Economics of Fiber Separation from Distillers Dried Grains with Solubles (DDGS) Using Sieving and Elutriation
Authors: Srinivasan Radhakrishnan , Singh Vijay , Belyea Ronald L. , Rausch Kent D. , Moreau Robert A. , Tumbleson M. E.
Published: June 2007

Separation of fiber from distillers dried grains with solubles (DDGS) provides two valuable coproducts: 1) enhanced DDGS with reduced fiber, increased fat and increased protein contents and 2) fiber. Recently, the elusieve process, a combination of sieving and elutriation was found to be effective in separating fiber from two commercial samples of DDGS (DDGS‐1 and DDGS‐2). Separation of fiber decreased the quantity of DDGS, but increased the value of DDGS by increasing protein content and produced a new coproduct with higher fiber content. Economic analysis was conducted to determine the payback period, net present value (NPV), and internal rate of return (IRR) of the elusieve process. The dependence of animal foodstuff prices on their protein content was determined. Equipment prices were obtained from industrial manufacturers. Relative to crude protein content of original DDGS, crude protein content of enhanced DDGS was higher by 8.0% for DDGS‐1 and by 6.3% for DDGS‐2. For a dry‐grind plant processing corn at the rate of 2,030 metric tonnes/day (80,000 bushels/day), increase in revenue due to the elusieve process would be $0.4 to 0.7M/year. Total capital investment for the elusieve process would be $1.4M and operating cost would be $0.1M/year. Payback period was estimated to be 2.5–4.6 years, NPV was $1.2–3.4M, and IRR was 20.5–39.5%.
Water Barrier Properties of Zein‐Oleic Acid Films
Authors: Wang Ying , Padua Graciela W.
Published: June 2007

Free‐standing films were prepared from zein formulations containing 30, 40, 50, 60, 70, and 80% oleic acid (OA). Zein/OA formulations were also used as coating films for rodent diet bars. Water vapor permeability (WVP) of films and moisture loss rate (MLR) of coated rodent diet bars were measured at 4 and 25°C. Temperature affected the water barrier properties of films and coatings. At 4°C, WVP of films decreased with OA concentration while it increased at 25°C. WVP behavior was attributed to oleic acid phase changes due to temperature. At 4°C, OA is a crystalline solid that limits water diffusion through the films. At 25°C, liquid OA increased the system free volume and allowed for water diffusion. The effect was more pronounced the higher the OA concentration in films. Differential scanning calorimetry (DSC) of zein/OA films showed endothermic peaks at 12–18°C, confirming the melting of OA in that temperature range. MLR of coated rodent diet bars was also affected by temperature and OA concentration in coating formulations. In this case, formulations containing 40, 50, and 60% OA were better moisture barriers than coatings with higher OA content at both 4 and 25°C. Moisture losses were reduced at 4°C due to OA solidification.
Effects of Micronization on Protein and Rheological Properties of Spring Wheat
Authors: Sun Shouchen , Watts Beverley M. , Lukow Odean M. , Arntfield Susan D.
Published: June 2007

This research investigated the effects of micronization, at different moisture levels, on the chemical and rheological properties of wheat. A set of tests designed to analyze protein fraction characteristics and rheological behaviors were conducted on samples from four wheat cultivars (AC Karma, AC Barrie, Glenlea, and Kanata). After being subjected to infrared radiation at three moisture levels (as‐is, 16%, and 22%), the seeds were milled to produce straight‐grade flour. The protein fractionation test revealed significant decreases (P ≤ 0.01) in both monomeric proteins (from 54% of total protein in the control to 37% in the tempered micronized sample) and soluble glutenins (9.4–2.5%). There was a strong negative correlation (r = ‐0.98) between the percentages of monomeric proteins and insoluble glutenins. Total extractable proteins of micronized samples tempered to 22% moisture decreased 43.5% when compared with nonmicronized control samples using size‐exclusion HPLC (SE‐HPLC). Micronization had a significant effect on gluten properties, as seen from a decrease in water absorption (P ≤ 0.01) and dough development time (P ≤ 0.01). Results showed that micronization at 100 ± 5°C had detrimental effects on wheat flour gluten functionality, including a decrease in protein solubility and impairment of rheological properties. These phenomena could be due to the formation of both hydrophobic and disulfide bonds in wheat during micronization.
Significance of Dietary Fiber on the Viscometric Pattern of Pasted and Gelled Flour‐Fiber Blends
Authors: Collar C. , Santos E. , Rosell C. M.
Published: June 2007

The aim of this research was to optimize mixtures of fibers from different sources and degree of processing meeting acceptable dough viscometric standards to design low‐calorie wheat bread formulations. Effects of soluble (inuline [FN]), partially soluble (sugar beet [FX]), pea cell wall (SW), and insoluble (pea hull [EX]) dietary fibers on wheat dough pasting and gelling profiles have been investigated. Impact of fibers added singly and in associated mixtures at different levels on the investigated viscometric parameters retrieved from a Rapid Visco Analyser curve has been assessed by response surface methodology, and the thermal parameters derived from the cooking and cooling functional profile were correlated. Flour replacement up to 34% by fibers significantly provided a deleterious effect on pasting and gelling viscosity profiles of the resulting hydrated high fiber‐flour blends. The magnitude of the reduction in dough viscometric characteristics during gelatinization, pasting, and setback closely depended on the nature of the fibers in the blend and on the extent of the flour substitution. A delayed and restricted swelling of starch granules and amylose leaching process preferentially achieved by the pair FN‐FX resulted in higher pasting temperatures and reduced peak viscosities during cooking and a sharp decrease of the setback on cooling. Single addition of FX, FN, and EX, respectively, provided a significant decrease in both breakdown viscosity and viscosity at the end of 95°C. Simultaneous presence of FN and EX that exhibit medium or low hydration properties allowed a partial restoration of initial breakdown viscosity and a simultaneous decrease in holding strength. Caution should be paid to the pairs FN‐FX and EX‐SW because of the adverse extra decline they induced in the viscosities of both hot paste and cold gel.
Effects of Physicochemical Characteristics and Lipid Distribution in Algerian Durum Wheat Semolinas on the Technological Quality of Couscous
Authors: Ounane Ghania , Cuq Bernard , Abecassis Joel , Yesli Abdenour , Ounane Sidi Mohamed
Published: June 2007

Semolinas milled from 18 Algerian durum wheat cultivars cropped over a two‐year period (1999‐2000) were used for making couscous. This study was designed to determine the impact of lipid components of durum wheat semolina on the quality of the couscous end product. Lipids were extracted from semolina by various techniques and classified as free or bound lipids, polar or apolar lipids, and glycolipids or phospholipids. An analysis of the overall results clearly revealed that the cooking quality of couscous made from different durum wheat semolinas was partially dependent on the semolina free lipid content and composition. We have shown that this is mainly a varietal characteristic (53.4%). The surface state of the couscous, i.e., caking index (r = ‐0.48) and cooking loss (r = ‐0.54), thus depends on the apolar lipid content. Polar lipids, and especially glycolipids, affect couscous texture in terms of firmness (r = 0.57 and r = 0.63, respectively). Polar bound lipids also contribute to couscous swelling (r = 0.53) and caking index (r = 0.70). Moreover, we obtained no correlation between cooked couscous quality and the semolina total lipid content (r < 0.3). We also showed that couscous characteristics were not significantly related to the semolina protein and dry gluten contents or gluten index (r < 0.3).
Retardation of Discoloration in Barley Flour Gel and Dough
Authors: Quinde‐Axtell Z. , Powers J. , Baik B.‐K.
Published: June 2007

Dark discoloration negatively influences the aesthetic properties of barley‐based food products. The effects of abrasion and heat treatment of grains, exclusion of oxygen, and the use of antibrowning agents on the retardation of darkening in barley flour gel or dough were determined in four types of barley, including hulled proanthocyanidin‐containing and hulled proanthocyanidin‐free, hulless regular, and hulless waxy barley. Abrasion by >30% in hulled barley and by >15% in hulless barley significantly increased the brightness (L*) of barley flour dough by 0.1–7.1. Steam heating of abraded grains also significantly increased the L* of barley flour gels by 1.8–3.4. Ascorbic acid at 1,500 ppm was most effective for retarding discoloration of barley flour dough, followed by 50 ppm of 4‐hexylresorcinol, which is an enzyme competitive inhibitor. The discoloration of barley flour dough was also effectively reduced by storing the dough sheets at 4°C under nitrogen gas to exclude oxygen or under anaerobic conditions at 20°C. Discoloration of barley‐based food products may be effectively controlled by selecting genotypes with low discoloration development such as proanthocyanidin‐free genotypes, by lowering total polyphenol content or polyphenol oxidase (PPO) activity through abrasion, by heat treatment, by exclusion of oxygen, and by the use of enzyme inhibitors.
Oligosaccharide Content and Composition of Legumes and Their Reduction by Soaking, Cooking, Ultrasound, and High Hydrostatic Pressure
Authors: Han In Hwa , Baik Byung‐Kee
Published: June 2007

Oligosaccharides, including raffinose, stachyose, ciceritol, and verbascose, are commonly found in legumes and often result in flatulence in humans. Effects of soaking, soaking with ultrasound (47 MHz), soaking with high hydrostatic pressure (HHP, 621 MPa), and subsequent cooking on the oligosaccharide content of lentils, chickpeas, peas, and soybeans were investigated. Legumes were soaked for 3 or 12 hr in water, soaked for 1.5 or 3 hr with ultrasound, or soaked for 0.5 or 1 hr with HHP. Oligosaccharides of lentils and chickpeas were mainly composed of raffinose, ciceritol, and stachyose, while those of peas and soybeans were raffinose and stachyose. Verbascose was the minor oligosaccharide in lentils and peas and was absent in chickpeas and soybeans. Ciceritol was not detected in peas and soybeans. Total oligosaccharide content of raw legumes ranged from 70.7 mg/g in yellow peas to 144.9 mg/g in chickpeas. Soaking was effective for the reduction of oligosaccharides in the tested legumes. Compared with soaking for 3 hr, soaking legumes with ultrasound for 3 hr in all tested legumes or soaking legumes with HHP for 1 hr, with exception of soybeans, appeared to be more effective for the reduction of oligosaccharides. The effect of cooking on the reduction of oligosaccharide content of presoaked legumes was evident in lentils, while oligosaccharide content of chickpeas, peas, and soybeans was either unchanged or even increased by cooking after presoaking, with or without ultrasound, probably due to the leaching of other soluble components and the release of bound oligosaccharides during cooking. During soaking or cooking of legumes, raffinose leached out faster than other oligosaccharides.
Capabilities of Oat Extracts in Inhibiting Cholesterol and Long Chain Fatty Acid Oxidation During Heating
Authors: Sun Ting , Xu Zhimin , Godber J. Samuel , Prinyawiwatkul Witoon
Published: June 2007

The antioxidant activities of oat groat extracts using different solvents were investigated. For acetone, hexane, and methanol extracts, the total phenolic compound contents were 12.83, 8.56, and 26.17 μg of catechin equivalent/g, respectively. Their corresponding free radical scavenging activities measured using the DPPH (2,2'‐diphenyl‐1‐picrylhydrazyl) method were 0.68, 0.35, and 0.79 μmol of Trolox equivalent/g, respectively. All oat extracts presented significantly greater capability in preventing cholesterol oxidation than the control (no extract added) during heating at the three levels of addition (1, 5, and 10 mg). The capability of the hexane or acetone extract in preventing cholesterol oxidation was not as effective as the methanol extract. In the docosahexaenoic acid (DHA, C22:6) oxidation test, all oat extracts at the level of 5 and 10 mg had greater inhibition capability on DHA oxidation than the control (DHA only). No significant inhibition was found for the hexane and acetone extract at the level of 1 mg, except for the methanol extract. The capabilities of oat extracts to inhibit oxidation of cholesterol and DHA from high to low was methanol, acetone, and hexane extract, which agreed with their free radical scavenging activities and total phenolic compound contents.
Evaluation and Strategies to Improve Fermentation Characteristics of Modified Dry‐Grind Corn Processes
Authors: Murthy Ganti S. , Singh Vijay , Johnston David B. , Rausch Kent D. , Tumbleson M. E.
Published: June 2007

New corn fractionation technologies that produce higher value coproducts from dry‐grind processing have been developed. Wet fractionation technologies involve a short soaking of corn followed by milling to recover germ and pericarp fiber in an aqueous medium before fermentation of degermed defibered slurry. In dry fractionation technologies, a dry degerm defiber (3D) process (similar to conventional corn dry‐milling) is used to separate germ and pericarp fiber before fermentation of the endosperm fraction. The effect of dry and wet fractionation technologies on the fermentation rates and ethanol yields were studied and compared with the conventional dry‐grind process. The wet process had the highest fermentation rate. The endosperm fraction obtained from 3D process had lowest fermentation rate and highest residual sugars at the end of fermentation. Strategies to improve the fermentation characteristics of endosperm fraction from 3D process were evaluated using two saccharification and fermentation processes. The endosperm fraction obtained from 3D process was liquefied by enzymatic hydrolysis and fermented using either separate saccharification (SS) and fermentation or simultaneous saccharification and fermentation (SSF). Corn germ soak water and B‐vitamins were added during fermentation to study the effect of micronutrient addition. Ethanol and sugar profiles were measured using HPLC. The endosperm fraction fermented using SSF produced higher ethanol yields than SS. Addition of B‐vitamins and germ soak water during SSF improved fermentation of 3D process and resulted in 2.6 and 2.3% (v/v) higher ethanol concentrations and fermentation rates compared with 3D process treatment with no addition of micronutrients.
Production of Thiyl Radical on a Peptide Derived from Wheat Protein by Superoxide Anion Radical
Authors: Miyamoto Yuka , Nishimura Kimio
Published: June 2007

In the current study, we examined the role of superoxide anion radical (O‐2) in the improvement of bread dough by l‐ascorbic acid. Because of difficulties in detecting thiyl radicals in the presence of l‐ascorbic acid, we replaced the latter with riboflavin, which produces O‐2 upon photoactivation. Nitro blue tetrazolium dye confirmed that O‐2 was produced in dough upon photoactivation of riboflavin. Electron spin resonance spectroscopy coupled with spin trapping showed that, in a solution containing riboflavin and the hydrolyzed gluten peptide (GP‐1), thiyl radicals are produced upon photoactivation. Addition of superoxide dismutase but not catalase suppressed the production of thiyl radicals on GP‐1. These results suggest that the O‐2 produced during the oxidation of l‐ascorbic acid in dough generates thiyl radicals on gluten proteins. This, in turn, would increase the production of interprotein disulfide bonds and result in an improvement in bread structure.
Application of Protease and High‐Intensity Ultrasound in Corn Starch Isolation from Degermed Corn Flour
Authors: Cameron Devon K. , Wang Ya‐Jane
Published: June 2007

The conventional corn wet‐milling process requires a long steeping time and has environmental and health concerns from the use of SO2. A recently proposed two‐stage enzymatic milling procedure with the first stage of water soaking and coarse grinding of corn and the second stage of incubating with enzymes has been shown to reduce the soaking time and possibly eliminate the need for SO2 addition. This current work explored the applications of protease and high‐intensity ultrasound in the second stage of the two‐stage enzymatic milling for corn starch isolation to further shorten the process time without use SO2. of The starch yield from sonication alone was 55.2–67.8% (starch db) as compared with 53.4% of the water‐only control with stirring for 1 hr and 71.1% of the conventional control with SO2 and lactic acid steeping for 48 hr. Protease digestion alone for 2 hr was not effective (45.8–63.9% yield) in isolating corn starch, but the starch recovery was increased to 61.2–76.1% when protease was combined with sonication. The preferred combination was neutral protease digestion for 2 hr followed by sonication at 75% amplitude for 30 min. The results demonstrated that combinations of high‐intensity ultrasound and neutral protease could replace SO2 and shorten the steeping time in the enzymatic wet‐milling process for corn starch isolation.
Properties of Cross‐Linked Starch from Waxy Mutant Wheat Tanikei A6599‐4
Authors: Kiribuchi‐Otobe Chikako , Fujita Masaya , Matsunaka Hitoshi , Sekine Masahiro
Published: June 2007

Native starch from waxy mutant wheat Tanikei A6599‐4 is known to exhibit more stable hot paste viscosity than a typical waxy wheat (Tanikei H1881) and waxy corn. The objective of this study was to investigate the starch paste properties of Tanikei A6599‐4 after cross‐linking and compare with Tanikei H1881 and waxy corn. As an example of cross‐linking, the reaction (at 30, 60, 120, and 360 min) with sodium trimetaphosphate was used. In Rapid Visco Analyser (RVA) measurement, the unique characteristic was maintained in Tanikei A6599‐4 starch cross‐linked at low reaction time (<120 min) levels. Cross‐linking at a high reaction time (360 min) level suppressed the swelling of both Tanikei A6599‐4 and Tanikei H1881 starches but not waxy corn starch. Although unmodified Tanikei A6599‐4 starch showed the lowest paste clarity among unmodified waxy starches, this defect became unremarkable when starch was cross‐linked for ≥120 min. In gel‐dispersed dynamic viscoelasticity measurement, the order of G′ and G″ values was always Tanikei A6599‐4 > Tanikei H1881 > waxy corn. This indicates that cross‐linked Tanikei A6599‐4 and Tanikei H1881 starches have different starch properties and that swollen Tanikei A6599‐4 starch granules are more rigid than swollen Tanikei H1881 starch granules.
Influence of Cultivar and Environment on Water‐Soluble and Water‐Insoluble Arabinoxylans in Soft Wheat
Authors: Finnie S. M. , Bettge A. D. , Morris C. F.
Published: June 2007

Arabinoxylans are hydrophilic nonstarch polysaccharides found in wheat grain as minor constituents. Arabinoxylans can associate with large amounts of water through hydrogen bonding and can form oxidative gels. These properties are important factors in end‐use quality of wheat. The objective of this study was to delineate the influence of wheat cultivar and growing environment on variation in water‐soluble (WS‐AX), waterinsoluble (WI‐AX), and total (TO‐AX) arabinoxylan contents of flour and whole grain meal. This study included seven spring and 20 winter soft white wheat cultivars grown in 10 and 12 environments, respectively (each evenly split over two crop years). Univariate analysis of variance (ANOVA) and multivariate analysis of variance with canonical analysis (MANOVA) was used to evaluate sources of variation. Variation in arabinoxylan contents and absolute amounts (xylose equivalents) among the two cultivar sample sets (spring and winter) was similar, and both cultivar and environment were significant sources of variation. The cultivar‐by‐environment interaction was relatively unimportant. Results indicate that the variation in arabinoxylan content is primarily influenced by cultivar and secondarily influenced by environment. Within arabinoxylan fractions, WS‐AX content is primarily influenced by genotype, while WI‐AX content is more greatly influenced by the environment.
Comparison of Raw Starch Hydrolyzing Enzyme with Conventional Liquefaction and Saccharification Enzymes in Dry‐Grind Corn Processing
Authors: Wang Ping , Singh Vijay , Xue Hua , Johnston David B. , Rausch Kent D. , Tumbleson M. E.
Published: June 2007

In a conventional dry‐grind corn process, starch is converted into dextrins using liquefaction enzymes at high temperatures (90–120°C) during a liquefaction step. Dextrins are hydrolyzed into sugars using saccharification enzymes during a simultaneous saccharification and fermentation (SSF) step. Recently, a raw starch hydrolyzing enzyme (RSH), Stargen 001, was developed that converts starch into dextrins at low temperatures (<48°C) and hydrolyzes dextrins into sugars during SSF. In this study, a dry‐grind corn process using RSH enzyme was compared with two combinations (DG1 and DG2) of commercial liquefaction and saccharification enzymes. Dry‐grind corn processes for all enzyme treatments were performed at the same process conditions except for the liquefaction step. For RSH and DG1 and DG2 treatments, ethanol concentrations at 72 hr of fermentation were 14.1–14.2% (v/v). All three enzyme treatments resulted in comparable ethanol conversion efficiencies, ethanol yields, and DDGS yields. Sugar profiles for the RSH treatment were different from DG1 and DG2 treatments, especially for glucose. During SSF, the highest glucose concentration for RSH treatment was 7% (w/v), whereas for DG1 and DG2 treatments, glucose concentrations had maximum of 19% (w/v). Glycerol concentrations were 0.5% (w/v) for RSH treatment and 0.8% (w/v) for DG1 and DG2 treatments.
Functional Properties of Hydroxypropylated, Cross‐Linked, and Hydroxypropylated Cross‐Linked Tuber and Root Starches
Authors: Gunaratne Anil , Corke Harold
Published: June 2007

Functional properties of some underexploited tuber and root starches (true yam, gourd yam, taro, lotus, and sweet potato) were investigated before and after hydroxypropylation, cross‐linking, and hydroxypropylation and cross‐linking using potato starch as the reference. Low swelling ability, poor viscosity development but high shear stability, gel hardness, and resistance to enzyme hydrolysis was observed in starches from true yam and gourd yam. The extent of retrogradation was also highest in these two starches. Most of the functional properties of lotus starch were similar to those of potato starch. Hydroxypropylation to a molar substitution level of ≈0.1 increased the swelling factor and susceptibility to α‐amylase hydrolysis but decreased acid tolerance of paste viscosity, retrogradation, gelatinization parameters, gel hardness, and shear stability. Cross‐linking decreased the swelling factor and amylose leaching, and increased shear stability and resistance to enzyme and acid tolerance. Cross‐linking had very little influence on gelatinization and retrogradation properties but a larger effect on pasting properties. Increased or decreased peak viscosities and gel hardness values were noted for different cross‐linked starches. Cross‐linking of hydroxypropylated starches increased commonly desirable functional properties providing a wider range of potential applications.
Pretreatment and Enzymatic Hydrolysis of Sorghum Bran
Authors: Corredor D. Y. , Bean S. , Wang D.
Published: June 2007

Sorghum bran has potential to serve as a low‐cost feedstock for production of fuel ethanol. Sorghum bran from a decortication process (10%) was used for this study. The approximate chemical composition of sorghum bran was 30% starch, 18% hemicellulose, 11% cellulose, 11% protein, 10% crude fat, and 3% ash. The objective of this research was to evaluate the effectiveness of selected pretreatment methods such as hot water, starch degradation, dilute acid hydrolysis, and combination of those methods on enzymatic hydrolysis of sorghum bran. Methods for pretreatment and enzymatic hydrolysis of sorghum bran involved hot water treatment (10% solid, w/v) at 130°C for 20 min, acid hydrolysis (H2SO4), starch degradation, and enzymatic hydrolysis (60 hr, 50°C, 0.9%, v/v) with commercial cellulase and hemicellulose enzymes. Total sugar yield by using enzymatic hydrolysis alone was 9%, obtained from 60 hr of enzyme hydrolysis. Hot water treatment facilitated and increased access of the enzymes to hemicellulose and cellulose, improving total sugar yield up to 34%. Using a combination of starch degradation, optimum hot water treatment, and optimum enzymatic hydrolysis resulted in maximum total sugar yield of up to 75%.
Effects on Soft Wheat (Triticum aestivum L.) Quality of Increased Puroindoline Dosage
Authors: Campbell J. B. , Martin J. M. , Crutcher F. , Meyer F. D. , Clark D. R. , Giroux M. J.
Published: June 2007

Wheat (Triticum aestivum L.) grain hardness affects many end‐product quality traits and is controlled primarily by the Hardness (Ha) locus that contains the Puroindoline a and b genes (Pina and Pinb, respectively). All soft hexaploid wheats carry the same Pin alleles, and hard wheats carry a mutation in Pina or Pinb. Here we test the heritability and milling and flour quality effects of increased Pin dosage in soft wheat. Previous experiments have suggested that grain softness can be enhanced by increasing Ha locus dosage through chromosome substitutions. Segregation data from a cross of cultivar Chinese Spring substitution lines with six doses of the Ha locus to the locally adapted soft wheat cultivar Vanna indicate that the substituted B genome Ha locus was not transmitted and that the A genome Ha locus was transmitted normally. Genotypes with the added Pins on the A genome produced seeds that were 7.4 hardness units softer. These softer double Ha genotypes were lower in flour yields, but produced flour with lower ash content, reduced starch damage, and smaller mean particle size. Soft wheats with increased Ha dosage may be useful in improving soft wheat quality through its effects on particle size and starch damage.
Characterization of Thermal Traits of Starches from Argentinian Maize Inbreds: Genotypic and Crop Year Variability
Authors: Eyhérabide G. , Borrás F. , Robutti J. , Presello D. , White P.
Published: June 2007

Thermal properties are among the most important end‐use characteristics of starch from maize (Zea mays L.). Knowledge of the contribution of genotype and environment to the total variance for starch thermal properties is needed to aid in defining a testing strategy for selecting maize with desirable thermal starch properties. Thus, the objectives of this study were 1) to characterize the thermal properties of starches from a group of recently developed Argentine maize inbred lines, and 2) to assess the variability in starch properties attributable to genetic and crop year effects. Twelve inbred lines developed by the National Institute of Agricultural Technology (INTA) in Argentina derived from a wide array of germplasm sources were evaluated. Gelatinization and retrogradation properties were measured by differential scanning calorimetry. Enthalpy means for gelatinization were below means reported in the literature, suggesting possible energy savings when using these starches. The ratio between change in enthalpy for retrogradation and gelatinization was above the mean reported in the literature, suggesting a starch that may be useful as a dietary fiber. Significant environmental effects caused by crop year were detected. Some inbred lines, with smaller observed ranges and standard deviations across environments, may be more stable for some properties.
Factors Impacting Ethanol Production from Grain Sorghum in the Dry‐Grind Process
Authors: Wu X. , Zhao R. , Bean S. R. , Seib P. A. , McLaren J. S. , Madl R. L. , Tuinstra M. , Lenz M. C. , Wang D.
Published: June 2007

The goal of this research is to understand the key factors affecting ethanol production from grain sorghum. Seventy genotypes and elite hybrids with a range of chemical compositions and physical properties selected from ≈1,200 sorghum lines were evaluated for ethanol production and were used to study the relationships of composition, grain structure, and physical features that affect ethanol yield and fermentation efficiency. Variations of 22% in ethanol yield and 9% in fermentation efficiency were observed among the 70 sorghum samples. Genotypes with high and low conversion efficiencies were associated with attributes that may be manipulated to improve fermentation efficiency. Major characteristics of the elite sorghum genotypes for ethanol production by the dry‐grind method include high starch content, rapid liquefaction, low viscosity during liquefaction, high fermentation speed, and high fermentation efficiency. Major factors adversely affecting the bioconversion process are tannin content, low protein digestibility, high mash viscosity, and an elevated concentration of amylose‐lipid complex in the mash.
Development and Characterization of Extruded Pellets of Whole Potato (Solanum tuberosum L.) Flour Expanded by Microwave Heating
Authors: Bastos‐Cardoso Isabela , de J. Zazueta‐Morales José , Martínez‐Bustos Fernando , Kil‐Chang Yoon
Published: June 2007

In various Latin American countries, large volumes of potato are classified as unsuitable for use as food and destined for use as feed. This raw material has a high starch and fiber content that could be used in the production of different kinds of food. The objective of this research was the preparation and characterization of extruded whole potato pellets expanded by microwave heating. A 33 central composite routable experimental design and response surface methodology were used. The barrel temperature (BT, 93–127°C), feed moisture (FM, 19–29%), and corn starch concentration (CS, 3–37%) in the blends were evaluated. CS was the most important variable affecting the functional properties of the expanded pellets. Adding CS to the blends increased the expansion index and viscosity and improved luminosity, decreasing the apparent density and breaking force of the products. Low BT and especially high FM increased the luminosity of the expanded pellets. Increasing FM content increased the viscosity of the expanded pellets. The best functional characteristics for the expanded pellets were obtained using a blend of 63% potato flour and 37% CS, extruded at 110°C BT with 24% FM content. Nonfood‐grade whole potato flour showed good potential for use in the production of expanded pellets with acceptable functional properties.
Molecular Characteristics of Corn Fiber Gum and Their Influence on CFG Emulsifying Properties
Authors: Yadav Madhav P. , Fishman Marshall L. , Chau Hoa K. , Johnston David B. , Hicks Kevin B.
Published: June 2007

The molecular characteristics of two purified arabinoxylan fractions derived from corn kernels, corn fiber gum‐1 and ‐2 (CFG‐1 and ‐2), have been studied and correlated with emulsifying properties. CFG‐1 and ‐2 fractions were isolated from different corn fiber sources by 1) a sequential alkaline extraction and H2O2 bleaching to produce CFG‐1; and 2) additional H2O2 treatment of the alkali‐extracted residue at pH 11.5, yielding CFG‐2. Multiangle laser light‐scattering and online viscosity were used to measure the molar mass, polydispersity, structure compactness, and intrinsic viscosity of the generated CFG fractions. Emulsification properties in an oil‐in‐water emulsion system with 10:1 oil‐to‐gum ratio was investigated by measuring turbidity of an aliquot from the bottom of the diluted emulsion over 10 days. The isolated CFG‐2 from each fiber source was higher in weight‐average molar mass (Mw) polydispersity) (Mw/Mn) and structure compactness, and also lower in solution weight‐average intrinsic viscosity (ηw) than the corresponding CFG‐1. Average Mw and ηw values were 244–491 kDa and 1.35–1.84 dL/g, respectively. The emulsion stabilizing capacity of CFG‐2 from each fiber source was superior to the corresponding CFG‐1.