bluuebunny/crossref_metadata_2025 huggingface dataset:
Detoxification of Rapeseed Meal by Extrusion with an Added Basic Salt
Authors: Barrett J. E. , Klopfenstein C. F. , Leipold H. W.
Published: June 2007

A commercial, high‐glucosinolate, rapeseed meal with no added salt or mixed with 2, 5, or 10% NH4HCO3 was extruded under different processing conditions using the Wenger TX‐52 twin‐screw extruder. Male Wistar rats were fed 13 diets containing 15% rapeseed meals (including nonextruded) or a casein‐based control diet. After six weeks, blood samples were taken, and serum was analyzed for thyroid hormones. Extrusion processing under all salt and steam conditions tested reduced glucosinolate levels in the meal, but no significant correlation was found between intensity of the treatment conditions and glucosinolate reduction. Higher weight gains, feed efficiencies, and thyroid hormone profiles were observed with use of the extruded meals; but no treatment completely detoxified the meal. Histopathological evaluation showed that thyroid and other tissue abnormalities occurred in all animals except those fed the casein diet. Antinutrients, including glucosinolates and probably volatile nitriles, in the meal were reduced by extrusion processing under the basic conditions of this experiment.
Effect of Lime on Gelatinization of Corn Flour and Starch
Authors: Bryant Cory M. , Hamaker Bruce R.
Published: June 2007

Analysis of swelling power, water retention capacity, and degree of gelatinization of corn flour cooked in water with and without lime indicated, over a concentration range of 0–1% (w/v), that at low concentrations, lime increases swelling and digestibility of starch granules. Measurement of starch solubility revealed an increase in the amount of starch dissolved by lime cooking. Swelling, retention, and gelatinization exhibited maxima at or near 0.2% (w/v) lime, and then decreased as lime concentration increased. Hot‐stage polarized light microscopy and differential scanning calorimetry of isolated starch revealed increasing gelatinization temperatures with increasing lime concentrations. It is hypothesized that the high pH of the system causes starch hydroxyl groups to ionize, thereby creating binding sites for Ca++/CaOH+ and producing Ca‐starch crosslinks. It is also suggested that, at low lime levels (<0.4%, w/v), granule crystalline regions are disrupted and the granule matrix is stretched by exchange of protons for calcium ions; when the lime level surpasses 0.4% (w/v), the granule shell becomes stabilized by Ca++‐starch interactions, producing stronger, more rigid granules.
Fortifying Bread with a Mixture of Wheat Fiber and Psyllium Husk Fiber Plus Three Antioxidants
Authors: Park H. , Seib P. A. , Chung O. K.
Published: June 2007

A 7:3 (w/w) mixture of wheat fiber (WF) and psyllium husk fiber (PHF) was substituted for 10wt% of flour on a 14% mb, and the protein in the blend was restored to 10.3% by incorporating vital wheat gluten. After adding 0.5% sodium stearoyl 2‐lactylate, the blend (100 g) was fortified with a combination of fat‐coated ascorbic acid (AsA), proteinencased (PE) β‐carotene, and cold‐water‐dispersible (CWD) all‐rac‐α‐tocopheryl acetate (ToAc) at levels of 72, 5.6, and 115 mg, respectively, of active material. Adding the fiber ingredients to the pup loaf formula increased water absorption 25% and mixing time 50% and imparted stickiness to the dough. The fiber and antioxidant bread showed a 10% reduction in loaf volume and a somewhat inferior crumb grain with an off‐color caused by small, black specks on a dark gray background. The crumb of the fiber and antioxidant bread remained much softer than control bread during one to seven days of storage at room temperature. Caramel coloring masked the off‐color. AsA was lost significantly faster in the fiber and antioxidant bread than in antioxidant bread; the losses of AsA were 97 and 86%, respectively, after three days at 25°C. Approximately 25% of β‐carotene was lost from the fiber and antioxidant bread after three days, and 33% after seven days, but the loss of ToAc was <10%. One serving size (one slice, 28 g) of fiber and antioxidant bread was calculated to provide 2.1 g of dietary fiber, or ~8% of daily value, of which ~30% was soluble. The three‐day‐old slice also contained vitamin E and vitamin A (as β‐carotene) at 120–150% and 12–15%, respectively, of the adult recommended daily allowances, but with 16% fewer calories than white pan bread.
Hybrid‐Dependent Effect of Lactic Acid on Corn Starch Yields
Authors: Singh V. , Haken A. E. , Niu Y. X. , Zou S. H. , Eckhoff S. R.
Published: June 2007

The effect of lactic acid on starch yields of different corn hybrids was determined by wet‐milling 18 commercial corn hybrids at three levels of lactic acid. All 18 hybrid samples tested had higher starch yields when lactic acid was added to the steep solution, although the magnitude of the increased starch yields varied between 2.9 and 12.0%. The optimal lactic acid concentration for maximum starch recovery was found to be between 0.55 and 1.67% lactic acid, by wet‐milling nine of the same 18 corn hybrids with seven levels of added lactic acid. Between 0.83 and 1.67% lactic acid, the starch yields of eight of the nine hybrids were constant (within ±0.5%). Results showed that the average starch yield across all hybrids decreased with a lactic acid concentration <0.55% and a lactic acid concentration >1.67%.
Factors Affecting Yield and Composition of Zein Extracted from Commercial Corn Gluten Meal
Authors: Wu Shaowen , Myers Deland J. , Johnson Lawrence A.
Published: June 2007

Twelve corn gluten meal samples obtained from six wet‐milling plants were processed into zein. Zein was extracted using 88% aqueous isopropyl alcohol at pH 12.5, followed by chilling. Protein recovery ranged from 21.3 to 32.0%, and protein purity ranged from 82.1 to 87.6%. Protein recovery increased as the protein purity increased (r = 0.76) (P < 0.01). One of the major factors influencing extraction yield was protein composition; especially α‐zein content, which ranged from 53.4 to 64% of the total protein in the corn gluten meal samples. The intensity of red color of the corn gluten meal was negatively correlated with protein recovery and zein purity (r = ‐0.66 and ‐0.72, respectively) (P < 0.02).
Effect of Extrusion Cooking on Extractable Lipids and Fatty Acid Composition in Sifted Oat Flour
Authors: Wicklund T. , Magnus E. M.
Published: June 2007

Sifted oat flour was processed at 25.0, 27.5, and 30.0% moisture content in a twin‐screw extruder at screw speed 300 rpm. The preset temperatures of the extruder barrel were 120, 150, or 180°C. Raw material and extrudates were analyzed for the content of diethyl ether‐extractable lipids, with and without hydrolysis, and the content of chloroformmethanol‐water saturated butanol (C/M/WSB) extractable lipids. The lipid extracts were analyzed for fatty acid (FA) composition. Percentage distribution of palmitic, oleic, and linoleic acids were significantly different in the different lipid extracts. Extrusion processing influenced the amounts of extractable lipids, while FA composition was not affected.
An Automated System for the Continuous Measurement of Time‐Dependent Changes in Noodle Color
Authors: Corke Harold , Au‐Yeung Lun , Chen Xiaofang
Published: June 2007

Fresh noodles may develop a gray discoloration over time during storage. This characteristic is related to polyphenoloxidase activity and is partly a varietal characteristic of the wheat flour; it is also influenced by processing conditions and is regarded as a major negative factor in noodle quality. Screening of wheat genotypes by measuring color at a fixed‐time interval (commonly 24 hr) after manufacture is not informative about time‐dependent color development. We developed a computer‐controlled automated sample platform attached to a reflectance spectrophotometer to simultaneously monitor color changes (L*, a*, b*) over time in up to 12 noodle samples. Application of the unit to monitor color changes in white‐salted and yellow‐alkaline noodles is described.
Effect of Oat Hull Fiber on Human Colonic Function and Serum Lipids
Authors: Stephen Alison M. , Dahl Wendy J. , Johns Dianne M. , Englyst Hans N.
Published: June 2007

Oat hull fiber is an insoluble source of dietary fiber, derived from the outermost layer of the oat grain. The effect of oat hull fiber on colonic function and serum lipids was investigated by conducting a controlled study on 10 healthy males, aged 20–37, who ate, for two three‐week periods, a controlled low fiber diet (13.1 g of nonstarch polysaccharide [NSP]/day), and the same diet with 25 g of oat hull fiber per day incorporated into foods, providing 17 g of NSP/day. Fecal weight increased from 113 ± 10.4 to 155 ± 10.8 g/day (P < 0.001) with no change in transit time or serum lipids. Fermentation of oat hull fiber was studied by analysis of feces for NSP. Excretion of NSP increased from 2.0 g/day excreted to 19.7 g/day, indicating that no degradation had occurred. Oat hull fiber is therefore resistant to fermentation in the human colon, has no effect on serum lipids, and provides no energy to the body
Composition of Oat Bran and Flour Prepared by Three Different Mechanisms of Dry Milling
Authors: Doehlert Douglas C. , Moore Wayne R.
Published: June 2007

Three mechanisms of oat milling were tested for laboratory‐scale oat bran production. Oat bran consistent with AACC definition and commercially obtained product was generated with either roller‐milling or impact‐milling of groats, followed by sieving to retain larger particles. These bran preparations were enriched ≈1.7‐fold in β‐glucan and ash, 1.4‐fold in protein, and 1.1‐fold in lipid. Bran finishing made further enrichments in protein, β‐glucan, and ash. Tempering oat (to 12% moisture for 20 min) improved bran yield from roller‐milling nearly two‐fold but had little effect on bran composition. Bran yield from the impact‐type mill was significantly affected by grinding screen size. Oat bran obtained from a pearling mill was only slightly enriched in β‐glucan and protein, but it was more heavily enriched in ash and oil than brans from roller or impact mills. The pearling mill isolated the outer layers of the groat directly, but because of its low β‐glucan composition it did not meet the AACC definition of oat bran, indicating a relatively uniform distribution of β‐glucan in the groat.
Diversity of Starch Pasting Properties in Iranian Hexaploid Wheat Landraces
Authors: Bhattacharya Monisha , Jafari‐Shabestari Jamshid , Qualset Calvin O. , Corke Harold
Published: June 2007

Wheat landraces possess a wide diversity in starch physical properties that could be useful in breeding for improved quality of specific products, such as various types of Asian noodles. The pasting properties (using a Rapid Visco‐Analyser [RVA]) and flour swelling volume (FSV, using silver nitrate to inactivate α‐amylase activity) of wholemeal, were measured for 242 hexaploid accessions of Iranian landrace wheat. FSV values and the peak viscosities were positively correlated (r = 0.73***). FSV values in the landraces ranged from 8.3 to 15.9 mL/g and peak viscosities ranged from 139 to 305 RVA units (RVU). In comparison, FSV of cvs. Eradu and Klasic were 18.6 and 15.0 mL/g, and peak viscosities were 355 and 303 RVU, respectively. Of the landraces, Iranian Wheat Accession (IWA) 8602488 had the highest peak viscosity (305 RVU) and exceptionally high hot‐ and cool‐paste viscosities. Two accessions, IWA 8602430 and 8600544, displayed pasting characteristics considered desirable for high‐quality Japanese white‐salted noodles. Four landraces were identified that had starch with unusually high resistance to shearthinning. Texture profile analysis was done on the wholemeal gels formed in the RVA canister. The variation in parameters such as hardness, chewiness, and adhesiveness in the landraces greatly exceeded that in the cultivars. The hot‐paste viscosity, breakdown, setback, and final viscosity values, but not the peak viscosity or FSV, were highly significantly correlated with the hardness, chewiness, and adhesiveness of the gel. The Iranian landraces appear to present useful genetic variation for developing wheats for special uses.
Use of Enzymes for the Separation of Protein from Rice Flour
Authors: Shih Frederick F. , Daigle Kim
Published: June 2007

When rice flour was treated with heat stable α‐amylases, the effectiveness of protein separation increased with increased temperature. Depending on the enzyme, treatment at 90°C for 45 min resulted in protein contents of 47–65% for the insoluble fraction. Prior gelatinization enhanced the effectiveness of the enzyme reaction but was undesirable because the increased viscosity and gelation could cause difficulties in the processing operation. Follow‐up treatment with other carbohydratehydrolyzing enzymes, such as glucoamylase, cellulase, and hemicellulase further increased the protein content up to 76% for the insoluble fraction. The subunit structure of the isolated proteins, based on electrophoretic analysis, remained practically unchanged after the treatment. The limited solubility and emulsion activity of rice protein were also unchanged.
Molecular Weight Distribution and (1→3)(1→4)‐β‐d‐Glucan Content of Consecutive Extracts of Various Oat and Barley Cultivars
Authors: Beer Michael U. , Wood Peter J. , Weisz John
Published: June 2007

The content and molecular weight (MW) of β‐glucan in extracts from a selection of oat and barley cultivars were compared using flow‐injection analysis and high‐performance size‐exclusion chromatography. From 60 to 75% of the β‐glucan was extracted from oat and waxy barley by hot water (90°C) containing heat‐stable α‐amylase, whereas just 50–55% was extracted from nonwaxy barley. Consecutive extractions with hot water and dimethylsulfoxide (DMSO) extracted 65% (nonwaxy barley) or 75–80% (oat and waxy barley) of the total β‐glucan. An extraction with sodium hydroxide and sodium borohydride (NaOH/NaBH4) increased the percentage of β‐glucan extracted to 86–100% but decreased the MW. The MW of β‐glucan in the oat cultivars selected was significantly higher than those in the barley cultivars. The β‐glucan extracted from the nonwaxy barley cultivars showed significantly higher peak MW than that from the waxy barley cultivars.
Optimization of Rapid‐Visco Analyser Test Conditions for Predicting Asian Noodle Quality
Authors: Batey I. L. , Curtin B. M. , Moore S. A.
Published: June 2007

A variety of Rapid‐Visco Analyser (RVA) operating conditions have been tested with starch, flour, and wholemeal for predicting the quality of wheats for the manufacture of Japanese white‐salted noodles. Using starch as the substrate, an initial temperature of 60°C has been found to be optimum, and the best heating time from this initial temperature to the peak temperature of 95°C was ≈6 min. Significant correlations were found between peak viscosity of starch pastes and noodle quality under these operating conditions. For flour and wholemeal samples, the correlations were not as high as for isolated starch. The correlations with wholemeal or flour and noodle quality could be improved by the addition of α‐amylase inhibitors. Measuring RVA viscosity of flour or wholemeal in the presence of silver nitrate gave viscosities which showed highly significant correlations with noodle quality. These correlations were similar to those obtained with isolated starch. It appears that the improvement is due to inhibition of the α‐amylase present in grain and flour. Correlations were also observed between flour paste viscosity and alkaline noodle quality. These could be increased either by inhibiting α‐amylase with silver nitrate or by pH adjustment with sodium carbonate but the change was not significant. The improvement of the correlations by α‐amylase inhibitors in this sample set was not as great as observed with Japanese white noodles.
Studies on the Glutathione‐Dehydroascorbate Oxidoreductase (EC 1.8.5.1) from Wheat Flour
Authors: Kaid Nadia , Rakotozafy Lalatiana , Potus Jacques , Nicolas Jacques
Published: June 2007

Glutathione (GSH) dehydrogenase was partially purified from wheat flour after extraction, ammonium sulfate precipitation, and ionic‐exchange chromatography on diethylaminoethyl (DEAE) Sepharose CL6B. Kinetic studies showed that the optimum pH was close to 7.5. The Km values varied between 0.15 and 0.28 mM for dehydroascorbic acid (DHA) and between 1.8 and 0.62 mM for GSH when pH was varied from 5.5 to 7.5. The kinetic pattern was consistent with a sequential mechanism for the binding of GSH and DHA. NaCl is a competitive inhibitor with respect to GSH and is uncompetitive with respect to DHA, which suggests that the enzyme combines with DHA before it does with GSH. IsoDHA can replace DHA as hydrogen acceptor but with a Km of 1.2 mM. γ‐Glu‐cys was enzymically oxidized but much less efficiently than GSH (Vm = 47 nkat/mL and Km = 5.5 mM compared to Vm = 362 nkat/mL and Km = 1.8 mM for GSH), whereas cysteine and cys‐gly were not substrates. In the presence of DHA, addition of cysteine and cys‐gly to small amounts of GSH causes a large activation of the enzymatic formation of ascorbic acid suggesting coupled oxidation of these thiols.
Effect of l‐Ascorbic Acid on the Rheological Properties of Wheat Flour‐Water Dough
Authors: Nakamura M. , Kurata T.
Published: June 2007

L‐Ascorbic acid (AsA) and its related compounds play an important role as improvers in bread production. Addition of AsA and its related compounds, such as dehydro‐L‐AsA (DHA) and 2,3‐diketo‐L‐gulonic acid (DKG), affected the rheological properties of flour‐water dough during mixing, especially hardness. Addition of 10 or 100 ppm AsA increased the dough hardness of samples as compared with the control dough. Addition of DHA or DKG to dough only slightly increased hardness. Addition of p‐quinone significantly increased the hardness. Both glutathione (GSH) and its oxidized form (GSSG) drastically decreased the hardness. Contents of AsA in the treated dough decreased and contents of DHA increased during mixing, suggesting that oxidation occurred. The oxidation rate of AsA was influenced by the concentration of AsA added. The improving effect of AsA on the rheological properties of flour‐water dough seemed to be mostly dependent on reactive intermediate oxidation products such as O2‐, while the contribution of DHA was rather limited.
Effect of Formula Water Content on the Spread of Sugar‐Snap Cookies
Authors: Miller R. A. , Hoseney R. C. , Morris C. F.
Published: June 2007

Sugar‐snap cookie doughs prepared with a commercial soft wheat flour and standard formula water (25%, fwb) produced baked cookies with a mean diameter of 186 mm. Increasing the formula water to 30% resulted in cookies with a mean diameter of 187 mm and decreasing the formula water to 20% resulted in cookies with a mean diameter of 185 mm. A similar effect was seen when the formula water in cookie doughs prepared with the pure hard red spring cultivar Butte 86 or the pure soft white winter club cultivar Paha was varied. Thus, varying the formula water in cookie dough appeared to have little or no effect on final cookie diameter. Formula water content, however, did affect cookie dough spread rate and set time during baking. Increasing the formula water caused the spread rate to increase but shortened the set time. As a result, final cookie diameter was essentially unchanged.
Effect of Kernel Size, Location, and Type of Damage on Popping Characteristics of Popcorn
Authors: Singh V. , Barreiro N. L. , McKinstry J. , Buriak P. , Eckhoff S. R.
Published: June 2007

Popping characteristics, specifically expansion volume and popping time, were studied for damaged popcorn. A single variety of commercial undamaged yellow popcorn was separated into four size fractions (D < 4.36, 4.36 < D < 5.16, 5.16 < D < 5.95, and D > 5.95 mm) by screening with round‐hole sieves. Kernels were damaged using a razor knife by either slicing a 2‐mm diameter piece of the endosperm or the germ or by cutting through the pericarp and seed coat into the endosperm or the germ ≈2 mm. A total of five combinations of location and damage were studied (tip cap removed, side cut, side sliced, germ cut, and germ sliced) for each kernel size. A control sample with no damage was also analyzed for each size fraction. All of the damaged kernels (regardless of type of damage) popped, but they had expansion volumes 9.1–47.5% smaller than those of undamaged kernels. The expansion volume of damaged kernels increased by 52.5–85.7%, depending on the damage, when the size of the kernel increased from <4.36 mm to >5.95 mm. Removing the tip cap and slicing through the germ caused less loss of expansion volume than did other types of damage. Damaged popcorn kernels had faster popping times (12.2–24.0 sec) than did undamaged kernels (30.9–34.6 sec). Popping times increased with increasing kernel size for all types of damage.
Effect of Nitrogen Fertilization on Quantity of Flour Protein Components, Dough Properties, and Breadmaking Quality of Wheat
Authors: Pechanek U. , Karger A. , Gröger S. , Charvat B. , Schöggl G. , Lelley T.
Published: June 2007

Three winter wheat varieties with differing breadmaking quality were grown at two locations in two years at 0 or 3 × 60 kg of nitrogen application. The effect of nitrogen on amount of different components of gluten proteins was determined by reverse‐phase HPLC. A high amount of nitrogen led generally to a significant increase of total protein content. However, this increase was obvious only for the gluten proteins; albumins and globulins remained nearly unaffected. The effect of increased protein content on gliadin to glutenin (gli‐glu) ratio was inconsistent. While increased protein content increased the gli‐glu ratio in the variety Capo, the opposite was true for the variety Renan. Gli‐glu ratio of the variety Lindos showed no discernible tendency. As total protein content increased, the ratio of low molecular weight (LMW) to high molecular weight (HMW) glutenins decreased consistently, i.e., in all varieties, in both years and locations. Change of LMW to HMW ratio showed a significant negative correlation to sedimentation value and bread volume. There was no consistent change in the ratio between x‐ and y‐type HMW subunits due to fertilization, as could be shown by densitometric measurements on SDS‐PAGE gels. This ratio appeared to be dependent on the genotype and has decreased with decreasing quality. The amount of x‐type subunits correlated closely with sedimentation value and bread volume. These results suggest that ratio of HMW glutenins, especially x‐type subunits, to total protein content could be the best early detectable parameter with high predictive value for breadmaking quality.
Distribution of Fusarium Molds and Fumonisins in Dry‐Milled Corn Fractions
Authors: Katta S. K. , Cagampang A. E. , Jackson L. S. , Bullerman L. B.
Published: June 2007

The distribution of Fusarium molds and fumonisins was determined in commercial and experimental dry‐milled corn fractions. Fusarium infection of the commercial whole corn samples ranged from 10 to 28%; F. moniliforme was the predominant species. Fusarium counts in corn fractions were <100 colony‐forming units (CFU)/g in flaking grits, <100 ‐ 6.4 × 104 CFU/g in bran, <100 − 1.6 × 104 CFU/g in germ, and <100 − 2.7 × 103 CFU/g in flour. Fumonisin concentrations were ≤0.1 μg/g in flaking grits, 0.2–1.1 μg/g in flour, 0.1–2.0 μg/g in germ, and 1.5–3.2 μg/g in bran. Yellow, blue, and white dent corns naturally contaminated with varying levels of fumonisins (25.4, 3.9, and 0.3 μg of fumonisin B1 per gram) and Fusarium molds (3.9 × 106, 8.0 × 105, and 2.6 × 104 CFU/g) were experimentally dry milled with a horizontal drum degermer. Number 5 grits contained significantly lower Fusarium counts and fumonisin concentrations than the whole kernel corn. Fusarium counts and fumonisins increased as grit size decreased, and high Fusarium counts and fumonisin concentrations were found in germ, bran, and fines.
Relationships Among Grain Sorghum Quality Factors
Authors: Buffo Roberto A. , Weller Curtis L. , Parkhurst Anne M.
Published: June 2007

Correlations among grain sorghum quality factors (proximate composition, physical properties, and water absorption properties) were evaluated. Samples of 46 commercial hybrids (24 and 22 from crop years 1993 and 1994) were analyzed for starch, protein, crude free fat, test weight, absolute density, 1,000 kernel weight, percent kernel abraded, water absorption index, initial water absorption rate, and moisture saturation point. Test weight, absolute density, and percent kernel abraded were positively correlated among themselves (r > 0.5). Protein was negatively correlated with both test weight and absolute density (r < ‐0.5), while moisture saturation point showed negative correlations with test weight, absolute density, 1,000 kernel weight, and percent kernel abraded (r < ‐0.4). Principal component factor analysis through the covariance matrix explained 95% of the total variation of quality factors among hybrids (two factors), and, through the correlation matrix, 85% of the total variation (five factors). Water absorption rate decreased with increasing starch content of grain sorghum kernels as water absorption rate increased and amount of water for saturation decreased with softening of kernels.
Rheological and Thermal Properties of Aged Starch Pastes from Three Waxy Maize Genotypes
Authors: Yuan R. C. , Thompson D. B.
Published: June 2007

The rheological and thermal properties of aged starch gels (15:85 starch‐water) from three waxy maize genotypes (wx, wx sh1, and du wx) during storage (4°C for up to 25 days) were studied. After storage, changes of storage modulus (G′) and phase angle (δ) of the gels as a function of temperature were measured using oscillatory rheometry. For the du wx samples, G′ at 25°C increased rapidly during the first four days of storage at 4°C, compared to the gradual increases over the 25‐day storage period for the wx and wx sh1 samples. A peak in G′ at 45°C was observed during heating for the du wx samples after 10 days of storage and for the wx sample stored for 25 days. The G′ peak may have been due to syneresis in the gels. Retrogradation of amylopectin of the aged starch samples was examined using differential scanning calorimetry. The du wx starch had greater retrogradation enthalpies than the other two samples (which showed similar retrogradation behavior) throughout the storage. The retrogradation enthalpy of the du wx samples increased rapidly during the first seven days, followed by a slower increase through the rest of storage. For the wx and wx sh1 samples, no endotherm was observed during the first four days of storage, after which the enthalpy increased steadily as a function of storage time. Addition of sucrose delayed the formation of gel networks for all three starches. The greater tendency for gelling and retrogradation of the du wx starch might be attributed to the greater proportion of DP20–30 chains of the amylopectin.
Fusarium Species and 8‐Keto‐Trichothecene Mycotoxins in Manitoba Barley
Authors: Abramson D. , Clear R. M. , Usleber E. , Gessler R. , Nowicki T. W. , Märtlbauer E.
Published: June 2007

Fusarium head blight, induced primarily by Fusarium graminearum, resulted in widespread damage to the Manitoba barley crops of 1993 and 1994, with contamination by deoxynivalenol (DON) and other 8‐keto‐trichothecenes. Visible Fusarium mold in samples of 1994 barley had little relationship to DON levels in the kernel as determined by gas chromatography‐mass spectrometry (GC‐MS). While samples of 1993 and 1994 barley showed a weak correlation between the logarithm of DON level and percentage of kernels infected by Fusarium graminearum (r = 0.79 and 0.71, respectively), the latter method is too lengthy and requires too much training for commercial application. A commercial enzyme immunoassay for DON gave results that correlated well with GC‐MS methods (r = 0.95 and 0.89, respectively) in samples of 1993 and 1994 barley and afforded a rapid and convenient method for screening. In barley samples from 1994, DON, 15‐acetylDON, 3‐acetylDON and 3,15‐diacetylDON were detected in the approximate ratio of 47:4:1:1. In view of the higher oral toxicities of 15‐acetylDON and 3‐acetylDON relative to DON, and the unknown oral toxicity of 3,15‐diacetylDON, GC‐MS assays might be advisable in samples positive for DON from enzyme immunoassay screening.
Differential Scanning Calorimetry Glass Transition Temperatures of White Bread and Mold Growth in the Putative Glassy State
Authors: Buera M. P. , Jouppila K. , Roos Y. H. , Chirife J.
Published: June 2007

Differential scanning calorimetry (DSC) was used to determine the onset and end temperatures of the glass transition (Tg) for white bread equilibrated between 53 and 84% rh. Calorimetric Tg end values were ≈20°C higher than onset values, indicating that it is probably more correct to refer to a “glass transition range” rather than a glass transition temperature. Slices of white bread inoculated with a mixture of xerophilic molds were equilibrated to 75% rh (equilibrium moisture content of 14.5 g of water/100 g of dry material) and stored at 26°C. In a parallel experiment, some of the equilibrated bread samples were stored without mold inoculation and subjected to spontaneous contamination from the immediate surroundings. As suggested by measured Tg, bread stored at 75% rh and 26°C appeared to be glassy. After storage, samples of bread (inoculated or not) were spoiled by xerophilic molds, suggesting that Tg, as measured by DSC, cannot be considered as an absolute threshold for mold growth inhibition.
Influence of Salts and Aggregation of Gluten Proteins on Reduction and Extraction of High Molecular Weight Glutenin Subunits of Wheat
Authors: Bean S. R. , Lookhart G. L.
Published: June 2007

High‐molecular weight glutenin subunits (HMW‐GS) of wheat were extracted by various combinations of reducing agents, salt solutions, and solvents. Preferential extraction of 1D‐encoded HMW‐GS occurred when flours were extracted with Tris‐HCl SDS buffer at pH 6.8 containing 6% mercaptoethanesulfonic acid sodium salt (MESNA) and analyzed by SDS‐PAGE. Similar effects were also found when dithiothreitol or β‐mercaptoethanol were used in conjunction with nonchaotropic salts. If flours were first extracted with 50% 1‐propanol, the extraction procedure yielded all HMW‐GS, even in the presence of MESNA or high levels of salts. Addition of alcohols or chaotropes to the Tris buffer solutions containing MESNA or of solutions containing salt also extracted all HMW‐GS. The HMW‐GS reported most important in baking quality were found preferentially extracted by nonchaotropic salts and reducing agents. This is related to gluten aggregation and the gliadin‐glutenin interaction and structure.
Effects of Postharvest Processing on Texture Profile Analysis of Cooked Rice
Authors: Champagne Elaine T. , Lyon Brenda G. , Min Bong Kee , Vinyard Bryan T. , Bett Karen L. , Barton Franklin E. , Webb Bill D. , McClung Anna M. , Moldenhauer Karen A. , Linscombe Steve , McKenzie Kent S. , Kohlwey David E.
Published: June 2007

The effects of drying conditions, final moisture content, and degree of milling on the texture of cooked rice varieties, as measured by texture profile analysis, were investigated. Instrumentally measured textural properties were not significantly (α = 0.05) affected by drying conditions, with the exception of cohesiveness. Cohesiveness was lower in rice dried at lower temperatures (18°C or ambient) than in that dried at the higher commercial temperatures. Final moisture content and degree of milling significantly (α = 0.05) affected textural property values for adhesiveness, cohesiveness, hardness, and springiness; their effects were interdependent. The effects of deep milling were more pronounced in the rice dried to 15% moisture than that dried to 12%. In general, textural property values for hardness were higher and those for cohesiveness, adhesiveness, and springiness were lower in regular‐milled rice dried to 15% moisture than in that dried to 12%. In contrast, hardness values were lower and cohesiveness, adhesiveness, and springiness values were higher in deep‐milled rice dried to 15% moisture than in that dried to 12% moisture. Deep milling resulted in rice with lower hardness values and higher cohesiveness, adhesiveness, and springiness values.
Near‐Infrared Reflectance Correlated to 100‐g Wet‐Milling Analysis in Maize
Authors: Dijkhuizen A. , Dudley J. W. , Rocheford T. R. , Haken A. E. , Eckhoff S. R.
Published: June 2007

An understanding of the genetic control of starch, protein, and oil concentrations in the corn (Zea mays L.) kernel is essential for improvement of grain quality. Because large numbers of progenies are needed for genetic studies, a rapid, accurate, analytical procedure is necessary. As part of a study to identify chromosomal regions associated with starch and protein, a rapid near‐infrared reflectance (NIR) method and a more labor‐intensive 100‐g wet‐milling procedure were compared for consistency in ranking families and identifying quantitative trait loci (QTL) using a set of 200 F2S1 families from the cross of the 70th generations of the Illinois High Protein (IHP) × Illinois Low Protein (ILP) corn strains. NIR starch and wet‐milling starch values were highly correlated (r = 0.80), as were NIR protein and gluten measured by wet‐milling (r = 0.72). Chromosomal regions associated with NIR starch and wet‐milling starch were generally the same. Fiber concentration was significantly negatively correlated with starch and positively correlated with protein. Chromosome regions with significant associations with starch also had significant associations with fiber. The NIR method is satisfactory for measuring starch and protein in material with a wide range of variability in the early stages of a corn‐breeding program.
Objective Rollability Method for Corn Tortilla Texture Measurement
Authors: Suhendro E. L. , Almeida‐Dominguez H. D. , Rooney L. W. , Waniska R. D.
Published: June 2007

An objective rollability method that imitates subjective rollability scores of corn tortilla texture was developed. Force and work required to pull an axle that caused a tortilla to roll around a dowel were measured. The sensitivity of the technique to detect changes in corn tortilla texture during storage was evaluated, and other factors affecting objective rollability and tortilla texture were studied. The objective rollability technique was fast, simple, and sensitive to changes in the tortillas, and worked effectively on commercial samples. Data was significantly correlated to subjective rollability and flexibility scores. Textural differences among fresh tortillas during the first 24 hr of storage, and among tortillas with different thicknesses and additives, were detected by the objective rollability method. Thicker tortillas required more force and work to roll than thin tortillas. The objective technique is more sensitive to changes in texture than subjective evaluations, which do not detect differences in tortilla variability during the first 24 hr after baking, and it can be used to evaluate the effect of formulation and processing changes on fresh and stored tortillas.
Effects of Enzymes and Oxidizing Agents on Shear Stress Relaxation of Wheat Flour Dough: Additions of Protease, Glucose Oxidase, Ascorbic Acid, and Potassium Bromate
Authors: Wikström Katarina , Eliasson Ann‐Charlotte
Published: June 2007

Measuring shear stress relaxation with an established research rheometer after slowly applying large strain proved useful for characterizing the effects of different chemical and enzymatic additives. Baking tests done with and without added ascorbic acid indicated that the method can be used for predicting effects of such additives on breadbaking quality. The relaxation process for dough is discussed in terms of two flow processes, one occurring at short time periods and the other at longer time periods. The slowly applied large strain shear stress relaxation method provides information about stress relaxation behavior during the second flow process. The effects of two enzymes (protease and glucose oxidase) and two chemical additives (ascorbic acid and potassium bromate) were studied. The results are presented as the stress relaxation curve with the corresponding rate plot and the initial value of the stress. Addition of the oxidizing agents increased the second flow process times and decreased the relaxation rate during the second process. Protease shortened the second flow process times and increased the relaxation rate during the second process. Glucose oxidase separated the two flow processes by increasing the relaxation time of the second process and decreasing the relaxation time of the first process.
An Improved Process for Isolation of Corn Fiber Gum
Authors: Doner Landis W. , Chau Hoa K. , Fishman Marshall L. , Hicks Kevin B.
Published: June 2007

Sequential alkaline extraction and alkaline hydrogen peroxide (AHP) bleaching have been used to prepare corn fiber gum in yields ranging from 21 to 40%, depending on the pH of the extraction medium. The pH was adjusted by using different ratios of NaOH and Ca(OH)2 The whitest product was obtained after AHP bleaching of the extract obtained using the lowest pH value. In order for the product gum to give its characteristic clear and low viscosity solutions, it was necessary to remove starch from the corn fiber substrate using α‐amylase. The water‐insoluble hemicellulose A fraction, a minor component, was removed by neutralizing AHP‐treated extracts before ethanol precipitation of the useful hemicellulose B (corn fiber gum) fraction. At ambient temperature, AHP bleaching was near optimal after ≈2 hr under the processing conditions used. High ratios of arabinose (39%) to xylose (50%) were present in the corn fiber gum extracted under various alkaline conditions, and the H2O2 processing step did not significantly alter these ratios. The same low levels of galactose (7%) and glucuronic acid (4%) were present regardless of the extraction conditions. Molecular mass of the corn fiber gum preparations ranged from 2.78 × 105 for the material extracted with Ca(OH)2 to 3.94 × 105 for the material extracted with NaOH. Molecular mass was unaffected by the H2O2 present in the second processing step. As expected for a carbohydrate polymer with a rather low uronic acid content, solution viscosities were unaffected by the presence of salt.
Characterization of Dynamic Viscoelastic Behavior of Wheat Flour Doughs at Different Moisture Contents
Authors: Masi P. , Cavella S. , Sepe M.
Published: June 2007

Three different flours were examined to study the influence of moisture content on the dynamic viscoelastic behavior of wheat flour dough. Doughs with moisture contents varying from 43 to 58% were submitted to dynamic testing using a mechanical spectrometer operating in frequency sweep mode, obtaining information about rheological response in the linear viscoelastic range. To characterize the influence of moisture content on the dynamic viscoelastic behavior of wheat flour dough, some hypotheses regarding the functional role of the water molecules were verified by applying reduction procedures of the rheological curves. By shifting the rheological curves along the vertical axis, it was possible to verify that varying the moisture content of the doughs not only changed dynamic properties but also modified viscoelastic response. By applying a reduction procedure similar to that used to estimate the constants of the Williams, Landel, and Ferry equation, we demonstrated that not only did the viscoelastic response of doughs vary, but that water molecules interfere with the dynamic by which relaxation phenomena take place. Finally, we proved that the rheological behavior of flour dough is similar to that of concentrated polymer solutions, and that it can be characterized by using a double reduction procedure, shifting the rheological curves along the vertical and horizontal axes, and obtaining a master curve that can be considered inherently characteristic of viscoelastic behavior.
Composition, Thermal Behavior, and Gel Texture of Prime and Tailings Starches from Garbanzo Beans and Peas
Authors: Czuchajowska Zuzanna , Otto Terri , Paszczynska Bozena , Baik Byung‐Kee
Published: June 2007

Prime and tailings starches of garbanzo beans and peas were separated and the chemical composition, physical properties, thermal behavior, and gel properties were determined. Starch granules <35 μm were 85% in garbanzo beans, 66.8% in a smooth pea cv. Latah, and only 18.4% in a smooth pea cv. SS Alaska. Amylose content of prime starch was 35.9% in garbanzo beans, 44.5–48.8% in smooth peas, and 86.0% in wrinkled pea cv. Scout. Tailings starch amylose content was at least 8% higher than the corresponding prime starch. The endothermic enthalpy value of garbanzo bean and two smooth pea prime starches ranged from 12.1 to 14.2 J/g, while prime starch from wrinkled peas gave a distinctly lower enthalpy value of 1.1 J/g. Differential scanning calorimetry endothermic enthalpy and amylograph pasting properties of prime starch were significantly related to its amylose content (P < 0.05). Prime starches of garbanzo beans and smooth peas produced highly cohesive elastic gels. Wrinkled pea prime starch formed the strongest (though brittle) gel, as indicated by high hardness (21.8 N), low cohesiveness (0.29), and low springiness (0.82). Hardness of gel stored at 22°C and at 4°C was positively correlated with amylose content of starch.
Intercultivar Variation in the Quantity of Monomeric Proteins, Soluble and Insoluble Glutenin, and Residue Protein in Wheat Flour and Relationships to Breadmaking Quality
Authors: Sapirstein H. D. , Fu B. X.
Published: June 2007

A new fractionation procedure based on differential solubility was applied to wheat flour proteins to evaluate the relationship between protein fractions and functionality for breadmaking. Flour was initially extracted with 50% 1‐propanol. Monomeric proteins (mainly gliadins) and soluble glutenin contained in the 50% propanol soluble extract were fractionated by selective precipitation of the glutenin by increasing the concentration of 1‐propanol to 70%; monomeric proteins remain in the supernatant. Insoluble glutenin in the 50% propanol insoluble residue was extracted using 50% 1‐propanol containing 1% dithiothreitol (DTT) at 60°C. Protein in the final residue was extracted using SDS with or without DTT. It comprised mainly Glu‐1D high molecular weight glutenin subunits and nongluten polypeptides. For seven Canadian cultivars of diverse breadmaking quality, there was relatively little variation in the percentage of flour protein corresponding to monomeric proteins (48–52%) and residue protein (14–18%). In contrast, intercultivar variation in soluble and insoluble glutenin was substantial, with contents of 10–20% and 12–28% of flour protein, respectively. Soluble and insoluble glutenin were also highly correlated with physical dough properties, accounting for 83–95% of the variation of individual dough rheological parameters (except dough extensibility), and ≈ 74% of the variation in loaf volume. In contrast, monomeric and residue protein fractions were poorly associated with breadmaking quality. However, among the four protein fractions, only residue protein was significantly correlated (r = ‐0.79) with dough extensibility. The flour sample with the highest and lowest concentrations of insoluble and soluble glutenin, respectively, as well as marginally the lowest concentrations of monomeric and residue proteins was Glenlea, a cultivar of the Canada Western Extra Strong Red Spring wheat class which characteristically possesses distinctly strong dough mixing properties.
Solubilization of Arabinoxylans from Isolated Water‐Unextractable Pentosans and Wheat Flour Doughs by Cell‐Wall‐Degrading Enzymes
Authors: Petit‐Benvegnen M.‐D. , Saulnier L. , Rouau X.
Published: June 2007

Water‐unextractable pentosans (WUP) isolated from the flours of three wheat cultivars (Apollo, Soissons, Thésée) were treated with enzymes to solubilize the arabinoxylans. The water‐unextractable arabinoxylans from the three cultivars had similar susceptibility to solubilization by enzymes: Grindamyl S 100 (GS100), a commercial preparation for baking, rich in pentosanase activities that originated from an Aspergillus niger culture; and three endoxylanases (E1, E2, E3), an arabinofuranosidase (Af), a β‐ glucanase (βG), and a ferulate esterase (FAE) purified from GS100. A cellulase (C) and a pure endoglucanase (eG) from Trichoderma reesei were also used. GS100 was able to solubilize high molecular weight arabinoxylans (HMWAX) from WUP that markedly enhance the viscosity of the reaction mixture supernatants. The endoxylanase E1 was responsible for this solubilizing activity of GS100, whereas E2 and E3 made only a very low contribution. Combining E1 with FAE led to a limited increase in the arabinoxylan‐solubilizing effect. Also, enzymes hydrolyzing cellulose and β‐glucans slightly improved the arabinoxylan solubilization from WUP when combined with GS100 or E1, but produced arabinoxylans of lower intrinsic viscosity. Similar effects of the enzymes were observed on arabinoxylan solubilization when applied to dough instead of isolated WUP.
A Simple Wheat Flour Swelling Test
Authors: Fu B. X. , Kovacs M. I. P. , Wang C.
Published: June 2007

Flour swelling tests have been widely used to assess the intercultivar differences in starch properties. This note describes a modified flour swelling test which uses ≈30 mg of flour. It avoids the use of a high‐temperature water bath, and does not require a set of uniform and leak‐proof tubes. The modified procedure offers a simpler and more rapid alternative to those previously reported, and provides a similar level of discrimination and precision. It is particularly suitable as a micro‐scale early generation test for wheat flour swelling properties.
Textural Images Analysis of Pasta Protein Networks to Determine Influence of Technological Processes
Authors: Fardet A. , Baldwin P. M. , Bertrand D. , Bouchet B. , Gallant D. J. , Barry J.‐L.
Published: June 2007

The structure of pasta is largely governed by the presence of a structured protein network. This work analyzed the protein network textures of various cooked pasta products through textural image analysis. Six different pasta types were investigated: reference pasta made from durum semolina; pasta enriched with gluten proteins from soft wheat flour at 10 and 20%; autoclaved pasta; soft wheat flour pasta; and pasta made from reconstituted flour fractions. Pasta samples were sectioned, and each crosssection consisted of three distinct zones (central, intermediate, and external) based on the state of swelling of starch granules for each pasta product. Digital images of the protein network in each zone were acquired using confocal laser scanning microscopy. Textural image analysis was then performed. Similarities and differences in protein network texture were assessed by principal component, stepwise discriminant, and variance analyses. With the exception of autoclaved pasta, protein network structure differed greatly with the position in the pasta. Furthermore the effect of technological treatments was greatly influenced by the position in pasta. The most significant differences in protein network structure were obtained with the autoclaved and 20% protein‐enriched samples.