bluuebunny/crossref_metadata_2025 huggingface dataset:
Action of Oxidants on Water Sorption, 2H Nuclear Magnetic Resonance Mobility, and Glass Transition Behavior of Gluten
Authors: Cherian George , Chinachoti Pavinee
Published: June 2007

Oxidation of vital wheat gluten with potassium bromate and ascorbic acid significantly extends or broadens glassy‐rubber transition to a higher final temperature range or moisture content. Thermomechanical and deuterium nuclear magnetic resonance (NMR) data show that the increased stiffness due to oxidation could be detected from the thermomechanical and deuterium NMR mobility level, indicating increased rigid fractions. The oxidation also resulted in increased water sorption, but no significant change in “freezable” water, and a much decreased mobile deuterium NMR signal. Room temperature sorption of water resulted in a glassy‐rubbery transition over a ≈10–20% mc range for the control. For the oxidized sample, it started at ≈10%mc, but the transition was gradual and extended into much higher moisture ranges that corresponded to a more rigid fraction of deuterium (NMR) signal. This suggests that the oxidative interactions led to a more rigid gluten fraction, extending the transition to a higher temperature range, perhaps resulting in a more elastic dough.
Simple Phenolic Acids in Flours Prepared from Canadian Wheat: Relationship to Ash Content, Color, and Polyphenol Oxidase Activity
Authors: Hatcher D. W. , Kruger J. E.
Published: June 2007

Simple phenolic acid levels were determined on pooled millstreams of five different classes of Canadian wheat milled to ~75, 80, and 85% extraction. Pooled flours and whole grain were analyzed by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) to establish endogenous levels of insoluble bound, soluble esterified, and free phenolic acids. Only ferulic acid was detected in the insoluble bound category, which accounted for >80% of the total phenolic acids present in every flour. The soluble esterified phenolic acids accounted for up to 17% of the overall total phenolic acid content within a flour. The major constituents were sinapic, ferulic, and vanillic acids, with minor amounts of coumaric, caffeic, and syringic acids. Free phenolic acids accounted for a maximum of 6% of the total phenolic content of any prepared flour. Ferulic acid was the major free phenolic acid, while sinapic acid was not detected in any flour. Significant correlations (r = 0.64–0.97, P < 0.05) were observed between insoluble bound ferulic acid, individual soluble esterified acids, and most free acids with polyphenol oxidase activity, as well as color and ash content for each class.
Retrogradation of Maize Starch After Thermal Treatment Within and Above the Gelatinization Temperature Range
Authors: Fisher Dane K. , Thompson Donald B.
Published: June 2007

Studies of starch retrogradation have not considered the initial thermal treatment. In this article, we explore the effect of heating to temperatures within and above the gelatinization range on maize starch retrogradation. In the first experiment, 30% suspensions of waxy (wx) starch were initially heated to final temperatures ranging from 54 to 72°C and held for 20 min. On reheating in the differential scanning calorimeter immediately after cooling, the residual gelatinization endotherm peak temperature increased, the endotherm narrowed, and enthalpy decreased. Samples stored for seven days at 4°C showed additional amylopectin retrogradation endotherms. Retrogradation increased dramatically as initial holding temperature increased from 60 to 72°C. In a second experiment, wx starch was initially heated to final temperatures from 54 to 180°C and rapidly cooled, followed by immediate reheating or storage at 4°C. Maximum amylopectin retrogradation enthalpy after storage was observed for initial heating to 82°C. Above 82°C, retrogradation enthalpy decreased as initial heating temperature increased. A similar effect for ae wx starch was observed, except that retrogradation occurred more rapidly than for wx starch. These experiments show that heating to various temperatures above the range of gelatinization may profoundly affect amylopectin retrogradation, perhaps due to varying extents of residual molecular order in starch materials that are commonly presumed to be fully gelatinized. This article shows that studies of starch retrogradation should take into account the thermal history of the samples even for temperatures above the gelatinization temperature range.
Bioavailability of Calcium in Breads Fortified with Different Calcium Sources
Authors: Ranhotra G. S. , Gelroth J. A. , Leinen S. D. , Schneller F. E.
Published: June 2007

This study used young rats as the test model to examine the relative bioavailability (RB) of calcium (Ca) in breads fortified with five different Ca sources. These sources included two inorganic (Ca carbonate and Ca sulfate) and two organic (Ca citrate and Ca lactate) Ca sources, and a brandname Ca supplement. RB was assessed based on rats' femur Ca content and Ca absorption data. No differences of any physiological significance were observed in RB of Ca among the five sources tested. Compared to Ca carbonate (bioavailability arbitrarily set at 100%), RB of Ca in Ca sulfate was 105%, in Ca citrate 103%, in Ca lactate 102%, and in the Ca supplement 102%. This suggests that foods fortified with Ca carbonate or Ca sulfate, which are commonly used for this purpose, may be as good a source of utilizable Ca as more expensive Ca sources such as prescribed or nonprescribed Ca supplements.
Detection of Irradiated Wheat Using the Electron Paramagnetic Resonance Spin Probe Technique
Authors: Dadayli Dilek , Sünnetçioğlu M. Maral , Köksel Hamit , Çelik Süeda
Published: June 2007

In this study, the electron paramagnetic resonance (EPR) spin probe technique is applied as a detection method in the differentiation of irradiated and unirradiated wheat seeds. Two wheat cultivars, Kunduru and Bezostaya, were used. Aqueous solutions of 4‐hydroxy‐TEMPO (TANOL) spin probe prepared with a line‐broadening agent, potassium ferricyanide, were used in all experiments. The EPR spectra of the samples were recorded against time. A decrease in the signal intensity and a change in the shape of the intensity‐time curve (rehydration curve) were observed, depending on the applied level of irradiation. The ratio of the lipid and aqueous regions at the high field (mI = ‐1) line changes, depending on the dose of irradiation.
Flavor Retention in Pregelatinized and Internally Flavored Starch Extrudates
Authors: Kollengode Anantha N. R. , Hanna Milford A.
Published: June 2007

Corn starch (25% amylose content) was pregelatinized in a twin‐screw extruder. The extrudate was ground and reextruded after adjusting moisture content to 9, 13, or 17% (db) and blending with 5% (w/w) of flavor compounds cinnamaldehyde, eugenol, nonanoic acid, or 3‐octanone. Initial moisture content significantly influenced radial expansion, specific mechanical energy, and flavor retention. Significantly higher flavor retention was obtained when flavor was injected into the extruder barrel as compared to preblending of flavors in pregelatinized starch. Flavor retention upon extrusion was lower with pregelatinized starch than with raw starch.
Preparation and Properties of Wheat and Corn Starch Maltodextrins with a Low Dextrose Equivalent
Authors: McPherson A. E. , Seib P. A.
Published: June 2007

Wheat and corn maltodextrins (W‐MD 8 and C‐MD 8) with dextrose equivalent (DE) 2–3 were prepared by heterogeneous bacterial α‐amylase digestion of a 15% starch paste at 95°C for 8 min followed by cooling and spray‐drying. Gels of the two maltodextrins appeared opaque with a glossy surface and melted reversibly at ≈65°C. Scanning electron micrographs showed that the products were divided finely and had few large remnants of starch granules. The fine granulation of W‐MD 8 and C‐MD 8 caused some clumping in cold water; homogeneous solutions were achieved with vigorous stirring at 90°C. Size‐exclusion chromatograms showed that the two products contained similar broad, molecular‐weight distributions of saccharides. A commercial potato maltodextrin marketed as a fat‐replacer contained fewer short‐length molecules when compared to W‐MD 8 and C‐MD 8, whereas a commercial corn maltodextrin fatreplacer contained more. High‐performance anion‐exchange chromatography with pulsed‐amperometric detection showed that all four maltodextrins contained only linear maltosaccharides between DP 2 and 25, with elevated levels of maltotriose and maltohexaose. The new wheat and corn maltodextrins contained 0.6–1.0% lipids and became rancid when stored at >30°C. The rancidity development in W‐MD 8 was eliminated either by alkali treatment of starting starch or by charcoal treatment of the warm hydrolyzate.
Properties of Some Starch Blends
Authors: Obanni Mohamed , Bemiller James N.
Published: June 2007

Normal corn, high‐amylose corn, waxy corn (waxy maize), wheat, rice, potato, cassava (tapioca), and a modified waxy corn starch were blended in various combinations and ratios. Pasting behavior, paste and thermal properties, and retrogradation tendency were determined. Differential scanning calorimetry (DSC) traces of the mixtures did not resemble those of either of the two components, nor did any DSC trace have two peaks suggestive of a mixture of two distinct starches. Amylograph data suggested that some mixtures behaved like a chemically modified starch. Observations from light microscopy suggested that intermolecular, molecular‐supermolecular, and intersupermolecular interactions may be responsible for this behavior.
Patterns of Barley Grain Development in Spain and Scotland and Their Implications for Malting Quality
Authors: Swanston J. S. , Ellis R. P. , Perez‐Vendrell A. , Voltas J. , Molina‐Cano J.‐L.
Published: June 2007

To determine whether patterns of grain filling were consistent between seasons and different between sites in northern and southern Europe, the cultivar Troubadour and TR49, a mutant derived from it, were grown, over two seasons, at sites in Scotland and northern Spain. Differences in sowing date and climate were reflected in different patterns of grain filling. Ear emergence in Scottish grown barley occurred around the time when daylight hours were maximal; optimal photosynthesis was the likely explanation for the rapid increase in grain size observed at the Scottish site. Differences between the sites in temperature and rainfall were most evident during the last month of the growing season. In Scotland, where ripening occurred in cooler, more humid conditions, synthesis of hordein and β‐glucan followed the pattern of grain filling, reaching a peak at ~600 degree days after anthesis (the product of days after anthesis and average temperature). Levels then remained fairly constant until harvest ripeness was reached. In Spain, levels of hordein and β‐glucan rose virtually throughout the growing season. Differences observed at maturity, between Scottish and Spanish grown grain, in total nitrogen and β‐glucan levels were due to this accumulation in the later stages of growth. This was accompanied by a major change in the ratio of the constituent polypeptides of the storage protein and differences in the relative proportions of soluble and insoluble β‐glucan.
Economics of Germ Preseparation for Dry‐Grind Ethanol Facilities
Authors: Singh V. , Eckhoff S. R.
Published: June 2007

A detailed economic analysis of a 914 tonnes/day (36,000 bu/day) “Quick Germ” ethanol process was performed. The Quick Germ ethanol process is a combination of a dry‐grind and a wet‐milling ethanol process. The Quick Germ ethanol process increases the coproduct value in the dry‐grind ethanol process by recovering germ before fermentation. Germ is recovered using the conventional wet‐milling degermination process. Economic assessment of the Quick Germ process proved profitable. The savings achieved by recovering germ as a coproduct and by increasing the fermentor capacity due to removal of nonfermentables from the corn mash will reduce the manufacturing cost of ethanol by 2.69 ¢/L (10.19 ¢/gal or $0.265/bu) when compared to the conventional dry‐grind ethanol process.
End‐Use Quality of Flour from Rhyzopertha dominica Infested Wheat
Authors: Sánchez‐Mariñez R. I. , Cortez‐Rocha M. O. , Ortega‐Dorame F. , Morales‐Valdes M. , Silveira M. I.
Published: June 2007

The objective of this study was to evaluate how Rhyzopertha dominica infestation of stored wheat grain affects the rheological and baking properties of bread made with the milled flour. Wheat samples were infested with R. dominica and stored for up to 180 days at room temperature. Every 45 days, samples of wheat were collected and evaluated for insect population and flour yield. Flour milled from these wheat samples was evaluated for color reflectance, pH, fat acidity, and rheological properties which were measured by a farinograph. Loaves of bread were baked using a straight‐dough procedure. Volume, height, and weight of the loaves were evaluated. None of the analyses performed on the control wheat flours showed any changes during the storage period, and they were similar to the initial wheat. The insect population increased during storage of the wheat up to 90 days, and the flour yield decreased with the storage up to 180 days. Flours from insect‐infested wheat absorbed more water than did flours from control wheat. Dough stability and dough development times of infested flours decreased. Bread volume showed a progressive decline throughout the storage experiment. In conclusion, flour from insect‐infested wheat exhibited changes in rheological properties such as dough stability, dough development times, water absorption, and mixing stability; bread had an offensive odor; and volume and loaf characteristics were negatively affected.
Retrogradation of Starches from Different Botanical Sources
Authors: Jacobson Mark R. , Obanni Mohamed , Bemiller James N.
Published: June 2007

Retrogradation in 2% pastes prepared from unmodified commercial starches by cooking at 98–100°C under low shear, then held at 4°C for 56 days, was examined by turbidometric analysis and light microscopy. Turbidometric analysis revealed that retrogradation rates followed the order of wheat, common corn > rice, tapioca, potato ≫ waxy maize. Microstructures of stored pastes were examined both before and after centrifugation. Granule remnant morphologies and fresh and stored paste microstructures were unique to each starch examined. Fresh pastes from amylose‐containing starches were dominated by networked amylose that condensed into higher density aggregates upon storage. Unique phenomena seen in some stored pastes included interactions of granular remnants with aggregated amylose, composite networks of co‐associated amylopectin and amylose, and slight birefringence regained by granule remnants. Microstructural changes in stored pastes could be related to changes in turbidity and to the results of other methods used to quantitate retrogradation.
Water Solubility and Macromolecular Properties of Corn Meal Extrudates as Affected by Epichlorohydrin
Authors: Kojima Masahiro , Hanna Milford A. , Gennadios Aristippos
Published: June 2007

Degermed corn meal adjusted to 18% moisture content (db) with epichlorohydrin (ECH) content at 0, 0.5, 1, or 2% (w/w) were extruded with a twin‐screw laboratory extruder at a screw speed of 140 rpm. Compression and metering barrel zones were set at 100, 120, or 140°C. Water solubility (WS) of ground extrudates ranged from 7.6 ± 1.1% to 14.3 ± 1.3%. ECH content had a significant (P < 0.01) negative effect on WS, while barrel temperature and the interaction between barrel temperature and ECH content were not significant (P > 0.05). Presumably, ECH reduced WS of extrudates through cross‐linking between hydroxyl groups on starch and protein molecules. Gel‐permeation chromatography patterns for both 100 and 140°C barrel temperatures showed that high molecular weight carbohydrates in the extrudates decreased with increasing ECH content without a simultaneous increase in low molecular weight carbohydrates. This suggested that the decrease in high molecular weight fractions was due to insolubilization by cross‐linking rather than degradation. SDS‐PAGE revealed that two protein bands of ≈29 and 17.5 kDa disappeared, and a new band appeared at 45 kDa with increasing ECH content. This indicated that, most likely, ECH reacted with protein in addition to reacting with starch. However, glycoprotein and starch‐protein complexes were not identified with electrophoresis.
Visualization of Channels and Cavities of Corn and Sorghum Starch Granules
Authors: Huber Kerry C. , BeMiller James N.
Published: June 2007

Evidence is presented that corn (maize) and sorghum starch granules have channels that connect a central cavity to the external environment. A mutant sorghum starch with numerous, large surface pores was treated with a methanolic solution of merbromin and sectioned. Light, fluorescence, and compositional backscattering electron microscopy revealed channels connecting an internal cavity to the external surface in most granules. Cavities and channels could also be seen in whole corn and sorghum starch granules treated with merbromin in methanol and viewed by fluorescence microscopy. Treatment of sorghum starch granules with an aqueous solution of merbromin revealed that the molecule penetrated the granule matrix under even slightly swelling conditions. Light microscopy showed cavities in unstained, whole, dry corn and sorghum starch granules mounted in immersion oil.
Structural Characteristics of Steam‐Flaked Sorghum
Authors: McDonough C. M. , Anderson B. J. , Rooney L. W.
Published: June 2007

Sorghum undergoes structural changes during tempering, steam cooking, and flaking at various tempering moisture levels. Physical properties of flakes, digestibility, birefringence, scanning electron microscopy (SEM), and environmental SEM (ESEM) were used to evaluate the quality of steam‐flaked sorghum from grain containing 11–23% water. As moisture levels increased, the flakes became stronger (57–69% whole flakes) and less dusty (9–4% fines). The diameter of the flakes varied among moisture levels, but preflake and final flake moisture contents increased as the temper level increased. Starch birefringence remained unchanged after tempering, and decreased only slightly after steam cooking; gelatinization occurred primarily during the flaking process. The steaming process prepared the grain for flaking by heating and softening the kernels. Tempering allowed extra water to penetrate inside the kernel endosperm. More starch granules had the opportunity to reach the glass transition temperature (T
g) during flaking. Based on subjective evaluation, birefringence, and SEM, poor quality flakes were opaque, chalky in appearance, and prone to high levels of breakage. The starch granules were more intact and less tightly packed into the flake. Good quality flakes were translucent, thin, and strong, with little chalkiness, and low levels of dust and fines. The dehydrated gelatinized starch continuous phase surrounding the granules reduced the amount of air spaces within the flake, increasing the translucency. ESEM inspection revealed that starch was more extensively gelatinized in the tempered samples. The starch granules were much larger in diameter, and the relative level of gelatinization, evident by the presence of starch granules with collapsed centers, was much higher.
Determining the Fat Acidity of Rough Rice by Near‐Infrared Reflectance Spectroscopy
Authors: Li Wang‐Sheng , Shaw Jai‐Tsung
Published: June 2007

Near‐infrared reflectance spectroscopy (NIRS) was used to develop calibration curves for determining the fat acidity of whole‐kernel and ground rough rice with 13% moisture content at 25°C. Partial‐leastsquares regression (PLSR) uses the optimal calibration curve for wholekernel rough rice to measure the coefficient of determination (r2) of validation and standard error of prediction (SEP) of 0.87 and 0.83 mg of KOH/100 g of dry matter, respectively. However, the optimal calibration curve for ground rough rice has a higher r2 of validation and lower SEP of 0.94 and 0.73 mg of KOH/100 g of dry matter, respectively. From 10 to 40°C, the temperature effect causes an increase of 0.24 mg of KOH/100 g of dry matter/°C in the predicted fat acidity of whole‐kernel rough rice.
Effects of Drying Conditions, Final Moisture Content, and Degree of Milling on Rice Flavor
Authors: Champagne Elaine T. , Bett Karen L. , Vinyard Bryan T. , Webb Bill D. , McClung Anna M. , Barton Franklin E. , Lyon Brenda G. , Moldenhauer Karen , Linscombe Steve , Kohlwey David
Published: June 2007

The extent that postharvest processing parameters influence the sensory quality of cooked rice is not well known. In this investigation, the effects of drying conditions, final moisture content, and degree of milling on the flavor of rice varieties Bengal, M‐401, and Koshihikari were determined by descriptive sensory analysis. No trends were observed indicating an increase or decrease in flavor attributes with increased drying temperatures (18–60°C). Intensities of desirable and undesirable flavor attributes were higher in rice dried to 15% moisture compared to 12% moisture. The effects of deep‐milling on flavor attribute intensities were dependent on moisture content and variety or location.
Recovery of Starch and Protein from Wet‐Milled Corn Fiber
Authors: Dowd Michael K.
Published: June 2007

Physical and chemical methods were used to recover starch and protein from wet‐milled corn fiber. A single milling of the fiber produced an 18% yield of mill starch. By separating the mill starch with a starch table, 68% of this material was recovered as starch with a protein contamination of 0.66%. Milling increased fine fiber from 4.5% in the starting material to 11.5% after a single grind. Successive additional milling passes modestly increased the mill starch and fine fiber yields with a corresponding decrease in the coarse fiber yield. Pretreatment with combinations of lactic and sulfurous acids had only a small effect on the distribution and composition of the recovered fractions.
Use of Elongational Viscosity to Estimate Cookie Diameter
Authors: Miller R. A. , Hoseney R. C.
Published: June 2007

Cookie diameter is a function of spread rate and set time during baking. Dough viscosity appears to control cookie spread rate and, thus, will affect final cookie diameter. The technique of lubricated uniaxial compression was used to measure the elongational viscosity of cookie dough. Full‐formula cookie doughs made with a commercial hard wheat flour had a significantly higher elongational viscosity (5.88 × 106 ± 9.17 × 104 Pa·S) than cookie doughs made with a commercial soft wheat flour (2.17 × 106 ± 1.05 × 104 Pa·S). Elongational viscosity correlated significantly (P < 0.05) with the diameter (r = ‐0.796) of cookies made with flours from various soft wheat cultivars. Using a simplified cookie formula decreased the testing time without greatly changing the correlation coefficient (r = ‐0.738). Thus, lubricated uniaxial compression appears to be an appropriate technique to measure the viscosity of cookie doughs and may be useful for predicting the cookie baking quality of soft wheat flours.
Starch Properties and Stability of Club and Soft White Winter Wheats from the Pacific Northwest of the United States
Authors: Lin P.‐Y. , Czuchajowska Z.
Published: June 2007

Based on examination of 192 club and soft white winter (SWW) wheat samples, club and SWW wheat flours showed comparable levels of starch damage and flour peak viscosity, while differing significantly in starch content. Varietal differences and growing conditions had strong influence on the characteristics of both classes of wheat flour. Club wheat flour exhibited better stability in starch content and starch damage than did SWW wheat flour. A significant correlation between starch damage and cookie diameter in both club and SWW wheat was observed (r = ‐0.480, P < 0.0001 for club wheat and r = ‐0.430, P < 0.0001 for SWW wheat). Sponge cake volume was positively correlated with starch content in both classes of wheat (r = 0.362, P < 0.01 for club wheat and r = 0.181, P < 0.05 for SWW wheat). When wheat samples were grown in one location over three years, club and SWW wheat flours had comparable starch content. However, flour and prime starch peak viscosities were significantly different in club than in SWW wheat. Club wheat flour had lower starch damage and amylose content, as measured by high‐performance size‐exclusion chromatography (HPSEC), than did SWW wheat flour. Crop year and varietal differences had significant effect on amylose content, starch damage, and flour and starch peak viscosities, but not on starch content, in both classes of wheat flour. When wheat samples were grown in one year over seven locations, club wheat flour was higher in starch content, lower in starch damage, and comparable in amylose to SWW wheat flour. Both flour and prime starch viscosities were significantly higher in club wheat than in SWW wheat. Varietal differences and growing location had strong influence on starch properties in both classes of wheat. Peak viscosity of the isolated starch did not correlate well with the corresponding flour, indicating that flour pasting property does not reflect the pasting property of starch. The fine structure of isoamylase‐debranched amylopectins from club and SWW wheats had a similar tri‐modal pattern, with maximum at ≈DP 15 and two valleys at ≈DP 20 and 45, respectively. Although wheat flour samples differed widely in their prime starch peak viscosity, no significant difference between debranching patterns was obtained. These results indicate that the fine structure of amylopectin might not be responsible for the large differences in prime starch pasting property.
Influence of Particle Size on the Twin‐Screw Extrusion of Corn Meal
Authors: Garber B. W. , Hsieh F. , Huff H. E.
Published: June 2007

Effects of particle size (50–1,622 μm), screw speed (200–400 rpm), and feed moisture content (19–22%) on twin‐screw extrusion of corn meal were investigated using a full‐factorial design. Torque, specific mechanical energy, and product temperature generally showed no change within the commonly used particle‐size range (100–1,000 μm), but each value dropped significantly as the particle size increased >1,000 μm. Die pressure was influenced by the three‐way interaction of particle size, screw speed, and feed moisture content. The highest moisture level (22%), largest particle size (1,622 μm), and two lowest screw speeds (200 and 300 rpm) were the only conditions where the starch was <97.5% of transformation (gelatinization). Consequently, these two conditions also showed the least expansion and hardest product.
Genetic Variation in Color of Sweetpotato Flour Related to Its Use in Wheat‐Based Composite Flour Products
Authors: Collado Lilia S. , Mabesa Linda B. , Corke Harold
Published: June 2007

Sweetpotato flours vary widely in color depending on genotype, and when used in wheat‐based composite flours, they will impart characteristic colors which may be favorable or unfavorable for particular food products. Sweetpotato flour (SPF) was prepared from 44 genotypes and analyzed for proximate composition and biochemical properties. The Hunter Color L*, a*, b* values of the dry SPF and their modified Pekar slicks (PS) with water and with alkali were measured. Polyphenol oxidase activity, α‐amylase activity, and total sugar were significantly correlated to L* values of dry SPF and of their PS tests with water and with alkali. The yellow pigment level was significantly correlated to the yellowness (b*) of the dry flour and of the PS test with water, but less correlated to b* of the PS test with alkaline. The results indicated a complex biochemical basis to SPF color, and no single biochemical factor examined was adequate to predict the color of a food product made from SPF. However, the PS color parameters were highly correlated with the color of dough sheets for white‐salted and yellow‐alkaline noodles made from wheat and sweetpotato composite flour (75:25). Thus, the simple modified PS test could be used in screening of genotypes for color stability and suitability for a specific end‐use. SPF genotypes conferred a wide range of colors on composite flour dough preparations. Some colors, particularly the range of greens and bright orange, may be useful in specialty product development.
Milling of Regular and Waxy Starch Hull‐less Barleys for the Production of Bran and Flour
Authors: Bhatty R. S.
Published: June 2007

Five registered cultivars of hull‐less barley (HB) with regular or waxy starch were milled in a Quadrumat Jr. mill to obtain whole grain flour; pearled in a Satake mill (cultivar Condor only), and the pearled fractions examined by microscopy to determine true HB bran. The samples were milled after tempering and drying in a Buhler mill to obtain bran and flour yields. Flour color and composition of HB were unaltered on milling in the Quadrumat Jr. mill. Microscopic evidence showed that a 70% pearl yield was devoid of the grain's outer coverings, including the aleurone and subaleurone layers. Therefore, the balance of 30% constitutes true bran in HB. Dry milling (as‐is grain moisture) of regular starch HB in the Buhler mill gave 59% total flour and 41% bran (bran + shorts) yields, the comparative values for the waxy starch HB were 42 and 58%. On tempering HB from 9 to 16% grain moisture, the total flour yield decreased in both types of HB but to a lesser extent in the waxy starch HB due to decreases in reduction flour. On drying HB to 5 or 7% moisture, total flour yields increased due to contamination with bran and shorts. The milling study led to the conclusion that HB, at best, be dry‐milled and a bran finisher be used to obtain commercial flour extraction rates. Lower total flour yields in the waxy starch HB than in the regular starch HB milled at the same grain moisture levels seemed due to higher β‐glucan rather than grain hardness. Waxy starch HB flour had higher mixograph water absorption and water‐holding capacity than regular starch HB or soft white wheat flour milled under identical conditions. Roller‐milled HB products offer the best potential for entry into the food market.
Effect of Cooking and Storage on the Amount and Molecular Weight of (1→3)(1→4)‐β‐d‐Glucan Extracted from Oat Products by an In Vitro Digestion System
Authors: Beer Michael U. , Wood Peter J. , Weisz John , Fillion Nicole
Published: June 2007

The extractability and molecular weight of β‐glucan in oat bran, oat bran muffins, and oat porridge and the changes taking place during processing and storage were studied. The β‐glucan was extracted using hot water and a thermostable α‐amylase and by an in vitro system that simulated human digestion. Molecular weight (MW) of the extracted β‐glucan was determined using high‐performance size‐exclusion chromatography. Hot‐water treatment extracted 50–70% of total β‐glucan in oat bran samples and rolled oats. The chromatographic peak MW of extracted β‐glucan was in the 1.4–1.8 × 106 range. Using the in vitro digestion system, 12–33% of total β‐glucan in bran and rolled oats was solubilized, and peak MW was in the same range as β‐glucan extracted by hot‐water treatment. In muffins, 30–85% of total β‐glucan was solubilized by in vitro digestion, with a major difference in extractability among muffins from different recipes. Peak MW of extracted β‐glucan was lower in all muffins when compared to original bran. During frozen storage, extractable β‐glucan decreased by >50% in all muffins, but no change in peak MW of extracted β‐glucan was detected.
Effects of Baking Temperature on Crumb‐Staling Kinetics
Authors: Giovanelli Gabriella , Peri Claudio , Borri Valeria
Published: June 2007

This study evaluated the effects of bread baking temperature on the staling kinetics of crumb. Bread dough was leavened and baked in sealed molds. Cooking trials were performed at various temperatures ranging from 90 to 110°C. The crumb samples were then stored at 20°C at constant moisture, and staling was evaluated by measuring crumb elastic modulus (using an Instron dynamometer) and starch retrogradation degree (using differential scanning calorimetry). Results show that the cooking temperature greatly influences bread staling. The lower the cooking temperature, the lower the staling rate, both in terms of crumb hardening and of starch retrogradation. Starch and protein solubility was evaluated on crumb cooked at 90 and 110°C. An increase in cooking temperature resulted in an increase in protein insolubilization and starch granule disruption.
Optimization of Temperature, Time, and Lactic Acid Concentration to Inactivate Lipoxygenase and Lipase and Preserve Phytase Activity in Barley (cv. Blenheim) During Soaking
Authors: Rutgersson A. , Bergman E.‐L. , Lingnert H. , Sandberg A.‐S.
Published: June 2007

A barley‐soaking process was studied to find conditions that inactivate the prooxidative enzyme lipoxygenase and the lipolytic enzyme lipase but preserve phytase activity to develop possible procedures for production of barley products with potentially high mineral bioavailability and good oxidative stability. Lactic acid concentration, temperature, and soaking time were studied. The study was done using a multivariate experimental design. Lactic acid concentration varied between 0 and 1%, temperature varied between 45 and 70°C, and soaking time varied between 30 and 120 min. Although conditions under which lipoxygenase was inactivated were found, total inactivation of lipase was not obtained. Total lipoxygenase inactivation with <20% remaining lipase activity and >60% remaining phytase activity was reached after soaking in 1% lactic acid at suitable time‐temperature combinations of 70–110 min and 53–58°C.
A Study of Maize Endosperm Hardness in Relation to Amylose Content and Susceptibility to Damage
Authors: Dombrink‐Kurtzman M. A. , Knutson C. A.
Published: June 2007

The relative amounts of amylose and amylopectin in maize starch were determined in samples representing hard and soft endosperm. Although differences were small, amylose content differed significantly (P < 0.001 and P < 0.05) between the two types of endosperm, with hard endosperm containing a higher percentage of amylose. Scanning electron microscopy was used to determine that the surface appearance of starch granules from hard and soft endosperm differed. Starch granules from soft endosperm had randomly distributed pores on their surfaces, which had a rough appearance. Few pores were observed on granules from hard endosperm. A fairly common occurrence with starch granules from soft endosperm was the development of wrinkles or fissures upon prolonged exposure to the beam of the electron microscope. Thus, a correlation existed between endosperm hardness, amylose content, and susceptibility to wrinkling and fissures. The granules of the soft endosperm of maize, presumably less mature than the granules of the hard endosperm, have a lower amylose content (20.5 ± 1.9% vs. 23.0 ± 1.0%), exhibit more surface pores, and are more susceptible to wrinkling in an electron beam, compared with granules of the hard endosperm. Results suggested that the composition and internal architecture of the starch granule differ depending on the hardness of the endosperm from which it was obtained.
Quantitative Determination of High Molecular Weight Glutenin Subunits of Hard Red Spring Wheat by SDS‐PAGE. I. Quantitative Effects of Total Amounts on Breadmaking Quality Characteristics
Authors: Huang Dong Yin , Khan Khalil
Published: June 2007

Thirteen hard red spring wheat genotypes in which seven genotypes had the same high molecular weight (HMW) glutenin subunits (2*, 7+9, 5+10) were compared for their physical‐chemical and breadmaking properties. These samples were categorized into three groups based on their dough mixing and baking performances as follows: the strong dough (SD) group (six genotypes), characterized by the strongest dough mixing (average stability, 35 min); the good loaf (GL) group (four genotypes), characterized by the largest loaf volume; and the poor loaf (PL) group (three genotypes), characterized by the smallest loaf volume. Total flour proteins were fractionated into 0.5M salt‐soluble proteins, 2% SDS‐soluble proteins, and residue proteins (insoluble in SDS buffer). SDS‐soluble proteins, residue proteins, and total flour proteins were analyzed by SDS‐PAGE and densitometry procedures to determine the proportions of HMW glutenin subunits, medium molecular weight proteins, and low molecular weight proteins in relation to the total amount of proteins. No differences in the amount of salt‐soluble proteins were found among the different groups of samples. Solubilities of gluten proteins (total proteins minus salt‐soluble proteins) in SDS buffer were related to the differences in dough strength and baking quality among the three groups. The SD group had the lowest solubility and the PL group had the highest. SDS‐PAGE analysis showed that SDS‐soluble proteins of the SD group contained a smaller amount of HMW glutenin subunits than those of the GL and PL groups. The highest proportions of HMW glutenin subunits in total flour proteins were found in the SD group, while the PL group had the lowest percentage of HMW glutenin subunits in their total flour proteins. These results showed that the total quantities of HMW glutenin subunits played an important role in determining the dough mixing strength and breadmaking performance of hard red spring wheats.
Quantitative Determination of High Molecular Weight Glutenin Subunits of Hard Red Spring Wheat by SDS‐PAGE. II. Quantitative Effects of Individual Subunits on Breadmaking Quality Characteristics
Authors: Huang Dong Yin , Khan Khalil
Published: June 2007

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

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

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

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

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

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

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