bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Wheat‐Flour‐Based Agropolymers: Influence of Plasticizers on Structure and Aging Behavior
Authors: Saiah R. , Sreekumar P. A. , Leblanc N. , Castandet M. , Saiter J.‐M.
Published: June 2007

Wheat‐flour‐based agropolymers are prepared using an extrusion method. The morphology of the native and extruded wheat flours are analyzed by scanning electron micrography (SEM). During plasticization using water (9%, w/w) and glycerol (12.8%, w/w), a change in morphology of native wheat flour occurs. The structure of these materials was investigated by X‐ray diffraction (XRD) with special reference to the amount of plasticizers used, such as water and glycerol molecules. The introduction of these plasticizers decreases the crystallinity rate and also increases the average distance between chains in the remaining vitreous phase of the extruded wheat flour. Replacing water molecules with glycerol reduces the crystalline phase and diminishes the average size of crystalline structures. The plasticization effects were confirmed by mechanical investigations. Indeed, increasing the amount of glycerol from 12.8 to 20% decreases the stress at failure and the tensile modulus, while the strain at failure increases. Finally, aging studies show that the percentage of crystallinity increases with time.
Study of Structural and Thermal Changes in Endosperm of Quality Protein Maize During Traditional Nixtamalization Process
Authors: Rojas‐Molina Isela , Gutierrez‐Cortez Elsa , Palacios‐Fonseca Alin , Baños Leticia , Pons‐Hernandez J. L. , Guzmán‐Maldonado S. H. , Pineda‐Gomez P. , Rodríguez M. E.
Published: June 2007

This work presents the study of the structural changes of the endosperm of Quality Protein Maize (QPM H‐368C), modified by alkaline cooking at two different temperatures (72 and 92°C) and steeping time of 0–7 hr. Structural changes in the outermost 10% layers, the subsequent 10%, and the remaining 80% of the endosperm as a function of the steeping time were studied using scanning electron microscopy (SEM), X‐ray diffraction, and differential scanning calorimetry (DSC) techniques. SEM images revealed that soft and hard endosperm have different shapes and packing factors. The X‐ray diffraction patterns of the hard and soft endosperm from raw corn suggest that the hard endosperm consists mainly of amylopectin and has a bigger relative crystallinity quality than the soft endosperm. Samples cooked at 72 and 92°C with and without the (Ca(OH)2 and steeped for 0, 3, and 7 hr, showed structural changes, X‐ray diffraction patterns from the outermost 10% layers and subsequent 10% of the endosperm were completely amorphous. This fact is related to the total or partial gelatinization of the starch. The crystallinity in the internal layers of endosperm (remaining 80%) did not have significant changes after the treatments and exhibited the characteristic patterns of crystalline amylose and amylopectin. DSC measurements in the outermost layers of the endosperm did not exhibit the characteristic endothermic peak of starch (from 64 to 81°C) compared with the raw sample, while the endotherm peak for 80% of the endosperm internal layers appears in all cases (72 and 92°C). According to these results, a new definition of the nixtamalization process can be developed as follows. During the nixtamalization process there is a total gelatinization of the starch granules from the most external layers, and a partial gelatinization of the innermost internal layers of the endosperm.
Genotypic and Environmental Variation for Flour Swelling Volume in Wheat
Authors: Morris C. F. , Shackley B. J. , King G. E. , Kidwell K. K.
Published: June 2007

The gelatinization and swelling of wheat (Triticum aestivum L.) starch has an important effect on the quality of end‐products, especially white salted noodles. This study was conducted to determine the genotypic and environmental variation for flour swelling volume (FSV) in wheat. FSV was measured for various spring and winter wheat cultivars grown in up to 31 unique environments and up to four crop years. Data were analyzed by organizing the data into eight balanced data sets. FSV ranged from ≈19 to 30 mL/g. Analysis of variance (ANOVA) indicated that cultivar was consistently a highly significant source of variation. Environments as unique combinations of locations and crop years were variably significant, as were locations, whereas crop years were always a significant source of variation. Only rarely were ANOVA interaction terms significant. Model R2 ranged from 0.87 to 0.98 for the eight data sets. Components of variation calculated from ANOVA model and total sums of squares indicated that cultivar accounted for 36.1–93.3% of the total variation. Environments, locations, and years accounted for 1.7–61.7% of the total variation. The relative variation assignable to the interaction of cultivars, environments, locations, or years never exceeded 10%. Penawawa was the highest FSV cultivar and was significantly higher than all other cultivars examined. In conclusion, FSV is highly and primarily influenced by cultivar and secondly by environment, crop year more so than location within a crop year. The small interaction of cultivar with environment suggests that FSV is highly heritable and that cultivar development programs can easily identify and track desirable FSV types. Incremental steps in FSV level were observed among the various cultivars and therefore optimum levels of FSV occurring throughout the range encountered should be attainable in new, improved cultivars.
Correlations Between the Fine Structure, Physicochemical Properties, and Retrogradation of Amylopectins from Taiwan Rice Varieties
Authors: Lu Shin , Chen Ling‐Ni , Lii Cheng‐Yi
Published: June 2007

Fourteen varieties of rice from Taiwan, including five Indica, five Japonica, and four waxy cultivars, were used in this study for the examination of fine structure and physicochemical properties of amylopectin. The results indicated that the amylopectin of Indica rice had lower molecular weight, lower average degree of polymerization (DP), and lower average chain number when compared to Japonica and waxy varieties. The shortest average DP was 6 glucose units for all 14 rice varieties. The average chain lengths (CL) of amylopectin were 18–22, 15–18, and 17–20 for Indica, Japonica, and waxy rice, respectively. Indica varieties with high amylose content had amylopectin that comprised a few extra long chains (DP >100). The CL distribution profiles of amylopectins for these 14 varieties could be divided into two factions: CL 10–15 and CL 40–44. Amylopectin of the Indica rice had a relatively high blue value and λmax, implying that a high proportion existed as long branches. The amylopectin of three Indica varieties with lower DP exhibited higher intrinsic viscosity, which might be attributed to the more elongated rod conformation of the few extra long chain amylopectins. The proportion of short chains with DP 6–9 glucose units seemed to influence the rate of the retrogradation of amylopectins.
Sources of Variation for Starch Gelatinization, Pasting, and Gelation Properties in Wheat
Authors: Zeng Ming , Morris Craig F. , Batey Ian L. , Wrigley Colin W.
Published: June 2007

The starch of wheat (Triticum aestivum L.) flour affects food product quality due to the temperature‐dependent interactions of starch with water during gelatinization, pasting, and gelation. The objective of this study was to determine the fundamental basis of variation in gelatinization, pasting, and gelation of prime starch derived from seven different wheat cultivars: Kanto 107, which is a partial waxy mutant line, and six near‐isogenic lines (NILs) differing in hardness. Complete pasting curves with extended 16‐min hold at 93°C were obtained using the Rapid Visco Analyser (RVA). Apparent amylose content ranged from 17.5 to 23.5%; total amylose content ranged from 22.8 to 28.2%. Starches exhibited significant variation in onset of gelatinization. However, none of the parameters measured consistently correlated with onset or other RVA curve parameters that preceded peak paste viscosity. Peak paste viscosity varied from 190 to 323 RVA units (RVU). Higher peak, greater breakdown, lower final viscosity, negative setback, and less total setback were associated with lower apparent and total amylose contents. Each 1% reduction in apparent or total amylose content corresponded to an increase in peak viscosity of about 22 and 25 RVU, respectively, at 12% starch concentration. Of the seven U.S. cultivars, the lower amylose cultivars Penawawa and Klasic were missing the granule‐bound starch synthase (GBSS; ADPglucose starch glycosyl transferase, EC 2.4.4.21) protein associated with the Waxy gene locus on chromosome 4A (Wx‐B1 locus). Kanto 107 was confirmed as missing both the 7A and 4A waxy proteins (Wx‐A1 and Wx‐B1 loci). The hardness NIL also were shown to be null at the 4A locus. Apparent and total amylose contents of prime starch generally corresponded well to the number of GBSS proteins; although the hardness NIL tended to have somewhat higher amylose contents than did the other GBSS 4A nulls. We concluded that reduced quantity of starch amylose due to decreased GBSS profoundly affects starch gelatinization, pasting, and gelation properties.
Amylose‐Lipid Complex Formation in Acetylated Pea Starch‐Lipid Systems
Authors: Liu Hua , Arntfield Susan D. , Holley Richard A. , Aime David B.
Published: June 2007

Starch‐lipid interactions involving native and acetylated pea starch were studied by differential scanning calorimetry (DSC) and measurements of iodine affinity. Lipids including lauric acid, monopalmitin, and butterfat were added to aqueous starch dispersions after the starch was gelatinized at 85°C. DSC thermal curves of gelatinized modified pea starch systems containing fatty acid or monoglyceride did not show DSC transitions indicative of amylose complexes with external lipids, whereas a DSC endotherm of amylose‐lipid complexes was observed for the corresponding native starch‐lipid systems. However, iodine binding studies revealed that acetylated pea starch amylose complexed with added fatty acid or monoglyceride in the modified pea starch‐lipid composites. The failure of DSC detection of the complexes in these systems was attributed to the absence of crystalline structures of acetylated pea starch amylose complexes. Furthermore, acetylation of starch decreased the complexing ability of the pea starch amylose as revealed by a reduction in iodine affinity. Both DSC and iodine affinity studies showed that neither native nor modified pea starch interacted to a significant extent with butterfat that consisted mainly of triglycerides.
Isolation of Hemicellulose from Corn Fiber by Alkaline Hydrogen Peroxide Extraction
Authors: Doner Landis W. , Hicks Kevin B.
Published: June 2007

For the first time, alkaline hydrogen peroxide (AHP) extraction conditions were used to isolate hemicellulose (arabinoxylan) from destarched corn fiber. Yields of the water‐soluble hemicellulose B ranged from 35% (24 hr extraction at 25°C) to 42% (2 hr extraction at 60°C). The hemicellulose B resulting from the 2 hr extraction (pH 11.5) was off‐white in color, and a very low proportion (1.7%) of water‐insoluble hemicellulose A was extracted. AHP treatment caused delignification and facilitated the alkaline extraction of hemicellulose from the lignocellulosic fiber matrix. In the absence of H2O2, yields were reduced by more than one‐third when using otherwise identical extraction conditions of time, temperature and pH. In the standard protocol, corn fiber, NaOH solution, and H2O2 were mixed in a 1:25:0.25 (w/v/w) ratio. Extractions were conducted at pH 11.5 at 25°C or 60°C. The pH was adjusted to 11.5 by addition of NaOH at ambient and elevated temperatures. The optimum hemicellulose yield (51.3%; dry, starch‐free basis) was obtained when the pH was increased to 12.5 for the final one‐half of the extraction period. Products obtained after extraction at pH values greater than 11.5 were tan in color, however, and the goal of the research has been to isolate white hemicellulose B and then evaluate its properties. Under most conditions, the yields ofhemicellulose B, potentially the most useful form for food and industrial applications, exceeded those of hemicellulose A by more than 10‐fold. The hemicellulose B products were lighter in color than those obtained using traditional alkaline extraction conditions of refluxing with calcium or sodium hydroxide. Steps prior to extractions with alkaline H2O2, such as grinding to 20 mesh and extracting with azeotropic toluene‐ethanol, were found to be unnecessary.
Flavor of Cereal Products—A Review
Authors: Grosch Werner , Schieberle Peter
Published: June 2007

The review is focused on studies presenting quantitative data and odor activity values (ratio of concentration to odor threshold) of key odorants in bread (wheat and rye), toasted bread, puff pastries made with different fats, fragrant and nonfragrant rices, sweet corn, popcorn, and tortillas. The influence of raw materials, processing parameters, and storage conditions on the concentrations of key odorants and some data on flavor precursors and formation pathways of these compounds are discussed.
Rheological Properties of Full‐Formula Doughs Derived from Near‐Isogenic 1BL/1RS Translocation Lines
Authors: Hussain A. , Lukow O. M. , Watts B. M. , McKenzie R. I. H.
Published: June 2007

Four pairs of near‐isogenic wheat lines, with and without the 1BL/1RS translocation, and differing at the Glu‐1 loci (coding for high molecular weight [HMW] glutenin subunits) were evaluated for their dough mixing properties, dough stickiness, and baking performance. In all 1BL/1RS translocation lines, weakening of the dough consistency occurred within 2 min past peak time. The full‐formula dough from every 1BL/1RS translocation line exhibited poor dough mixing characteristics and increased stickiness compared to the corresponding wheat control. The HMW glutenin subunits coded by the Glu‐A1 locus had no apparent effect on mixing properties, but did have a slight effect on the dough stickiness at two of the four stages of dough mixing. Glu‐B1 and Glu‐D1 loci encoded glutenin subunits produced significant changes in dough mixing properties and dough stickiness, respectively. With respect to baking performance, there was no significant difference between loaf volumes of 1BL/1RS versus control wheats for three of four near‐isogenic pairs. Within the 1RS‐group, the translocation lines containing HMW glutenin subunits 5+10 produced bread with greater loaf volumes than the pairs containing its allelic counterpart 2+12. Loaf volume was not influenced by the subunits associated with the Glu‐B1 loci. In general, the breads baked from 1BL/1RS translocation lines had a relatively poor crumb and crust quality and contained larger gas cells than the wheat controls. In comparing isogenic pairs, the magnitude of the difference in loaf volume between the control wheat and the corresponding 1BL/1RS translocation line was greater in the pair unique for HMW subunits 5+10; the difference was primarily due to the stronger mixing properties of the wheat control.
Effect of a Wheat Protein on pH‐Dependent Water‐Binding Capacity and Viscosity of Wheat Tailings Fractions
Authors: Seguchi Masaharu , Hayashi Machiko , Matsumoto Hiroshi
Published: June 2007

Wheat flour was fractionated with acetic acid using a mortar and pestle method or a blender method. Higher pH‐dependent water‐binding capacity (WBC) and viscosity were obtained only in the tailings fraction. The higher pH‐dependent WBC was rather stable at 5–37°C, however it decreased with salt addition. Pepsin or bromelain treatment stopped the pH‐dependent changes in WBC and viscosity, which suggests that this characteristic of the tailings fraction is due to the presence of proteins. HPLC indicated that the Mr of the proteins associated with high WBC at low pH was >200 kDa.
Waxy Starch Barley Genotypes with Reduced β‐Glucan Contents
Authors: Swanston J. S.
Published: June 2007

Random inbred lines were produced from a cross between the genotypes Chalky Glenn and Waxy Hector, and two‐row lines were classified as waxy or nonwaxy by an iodine staining test. Mean nitrogen and β‐glucan contents of the waxy types were higher than those of the nonwaxy types but, in contrast to previous data, mean milling energies of the two groups were not significantly different. Waxy lines with low milling energy had much lower β‐glucan levels than those with high milling energy, and they also demonstrated much more extensive cell wall modification during malting. From a trial grown the following season, the waxy types with low milling energy were again identified and had levels of β‐glucan content similar to those of nonwaxy types. β‐Glucan contents and, particularly, milling energies showed good agreement between seasons. It is suggested that, although waxy starch is usually associated with high β‐glucan content, a genetic factor from Chalky Glenn that confers low levels of β‐glucan can express in a waxy background.
Effect of NaOH on Visible Wavelength Spectra of Single Wheat Kernels and Color Classification Efficiency
Authors: Dowell F. E.
Published: June 2007

A diode‐array system, which measures spectral reflectance from 400 to 700 nm, was used to quantify single wheat kernel color before and after soaking in NaOH as a means of determining color class. Wheat color classification is currently a subjective determination and important in determining the end‐use of the wheat. Soaking kernels in NaOH and classifying the soaked kernels with the diode‐array system resulted in more difficult‐to‐classify kernels correctly classified (98.1%) than the visual method of classifying kernels (74.8%). Kernel orientation had a slight effect on correct classification, with the side view correctly classifying more kernels than the dorsal or crease view. The diode‐array system provided a means of quantifying kernel color and eliminated inspector subjectivity when determining color class.
Comparison of Work Input Requirement on Laboratory‐Scale and Industrial‐Scale Mechanical Dough Development Mixers
Authors: Wilson A. J. , Wooding A. R. , Morgenstern M. P.
Published: June 2007

The use of a laboratory‐scale mixer for predicting the mixing requirement of flours in an industrial‐scale mixer was investigated by measuring the work input required to mix a range of flours to peak consistency on both a laboratory‐scale and an industrial‐scale mechanical dough development (MDD) mixer. The industrial mixer used was a Tweedy‐type mixer, and the mixing optimum was determined using a probe that sensed changes in dough consistency. Work input was estimated from mixer motor power, taking into account expected motor and drive chain losses, and from dough temperature rise measurements. The laboratory mixer used twin flat‐bladed rotors; mixing optimum and work input were determined from the torque measurement. Work inputs from both mixers were highly correlated (r2 = 0.88) but with a large offset (the industrial mixer requiring more work to develop the dough). The two methods of measuring industrial mixer work inputs gave slightly different results leading to uncertainty as to the actual work given by the industrial mixer. Farinograph mixing properties were less well correlated with industrial‐scale work input requirement than the laboratory‐scale MDD mixer.
Effects of Lactic Acid, Acetic Acid, and Table Salt on Fundamental Rheological Properties of Wheat Dough
Authors: Wehrle K. , Grau H. , Arendt E. K.
Published: June 2007

The effects of the main metabolites, lactic and acetic acids, from the sourdough process on wheat doughs were tested with a dynamic sinusoidal oscillation test. Tests were done with a controlled stress rheometer. Dough treatment included four mixing times and four rest times before measurement. Phase angle, complex modulus, and viscosity were measured for all doughs at selected rest and mixing times, at frequencies ranging from 0.01–10 Hz. Results for all combinations of mixing and rest times were compared at 10 Hz. Effects of mixing time were most visible immediately after mixing and disappeared partially during rest time. Doughs that contained acid but no salt showed the clearest characteristics of overmixing, expressed by an increase in phase angle and decrease in complex modulus.
Properties and Microstructure of Plasticized Zein Films
Authors: Lai Huey‐Min , Padua Graciela W.
Published: June 2007

A new method for preparation of zein films involving plasticization of zein with oleic acid to form an intermediate moldable resin was presented. The resin was stretched over rigid frames to form thin membranes that were set in flexible films. The objective of the study was to investigate the effect of film preparation method on film properties. Tensile properties, microstructure, and thermal behavior of zein films plasticized with oleic acid were investigated for films prepared by conventional casting from ethanol solutions and by stretching of plasticized resins. Cast films were stiff and brittle, whereas resin films showed more flexibility and toughness. Differential scanning calorimetry thermograms of cast films indicated phase separations were generated when heated that were not observed for resin films. Microstructure images showed a higher degree of structure development and orientation in resin than in cast films. Glass‐transition temperatures of resin films were measured at ‐94 and 104.4° C, indicating the film remained flexible through a wide temperature range. Resin film flexibility and toughness were attributed to effective plasticization that led to fiber formation and orientation.
Water Distribution in Frozen Lean Wheat Doughs
Authors: Räsänen J. , Blanshard J. M. V. , Siitari‐Kauppi M. , Autio K.
Published: June 2007

Frozen storage increased the amount of liquid phase and decreased the storage modulus of water‐flour mixtures. The liquid phase was studied by ultracentrifugation. The most significant change occurred during the first week of storage. The negative effects of ice crystals could be controlled by reducing the water content, which was seen as smaller amounts of liquid phase and higher dough rigidity after frozen storage (G′ values). Reduced water content also prevented an increase in the self‐diffusion coefficient during frozen storage (1H NMR studies). Prefermented frozen doughs were examined under different conditions: with and without Skimo (additive from Puratos, Belgium), prefermentation time of 25 or 40 min, and reduced water content. The results obtained with autoradiographic method correlated best with the baking results and showed that S‐kimo and shorter prefermentation time improve the water distribution of frozen prefermented doughs. Doughs contained small ice crystals after frozen storage and there were no large water patches in thawed doughs. Reduced water content and exclusion of S‐kimo decreased the liquid phase of fermented doughs and increased dough rigidity. The baking properties of frozen prefermented doughs were better predicted by large deformation rheology (expansion potential of samples during oscillation). In general, flour quality had an obvious effect on the parameters. There was no correlation between the rheological properties and the values of liquid phase, but in most cases a high correlation between the total water content and rheological properties was observed.
Quantifying Surface Lipid Content of Milled Rice via Visible/Near‐Infrared Spectroscopy
Authors: Chen H. , Marks B. P. , Siebenmorgen T. J.
Published: June 2007

Visible/near‐infrared calibrations were developed and tested for surface lipid content (SLC) of milled long‐grain rice. Three rice varieties were divided into two sample sets, with one containing two variables (degree of milling and variety) and another containing three variables (degree of milling, variety, and kernel thickness). The reflectance calibration equation from the set with three variables was much more accurate in predicting SLC than was the calibration from the two‐variable set. Optimal calibration and prediction were obtained by combining both visible and near‐infrared wavelength ranges and using the modified partial least squares technique on spectra pretreated by standard normal variate and first derivative methods. The best calibration yielded a coefficient of determination (R2) of 0.99 and a standard error of prediction of 0.04% SLC, which was approximately 1.5 times the standard error of calibration and also 1.5 times the SLC measurement error.
Effects of Rough Rice Storage Conditions on the Amylograph and Cooking Properties of Medium‐Grain Rice cv. Bengal
Authors: Perdon A. A. , Marks B. P. , Siebenmorgen T. J. , Reid N. B.
Published: June 2007

Rough rice (cv. Bengal) was stored at four moisture contents (8.8, 10.7, 12.9, and 13.6% MC) and three temperatures (3, 20, and 37°C) for up to six months. The amylograph overall paste viscosity of the milled rice increased during storage. This increase was most apparent in all samples stored at 37°C. For rice stored at 20 and 37°C at all MC levels, a 30–50% increase in peak viscosity (PV) was observed during the first three months of storage. PV subsequently leveled off for rice stored at 12.9 and 13.6% MC but declined for samples stored at 8.8 and 10.7% MC. The final viscosities also increased during storage. The water‐absorption ratio of the samples during cooking in excess water increased by an average of 15% over six months of storage. The amylograph and cooking properties were significantly affected (P < 0.05) by rough rice storage duration, temperature, MC, and their respective interactions.
Influence of Kernel Damage on Corn Nutrient Composition, Dry Matter Losses, and Processability During Alkaline Cooking
Authors: Almeida‐Domínguez H. D. , Ordoñez‐Durán G. G. , Almeida N. G.
Published: June 2007

The nutrient losses of corn containing 0–30% damaged kernels that occurred during alkaline cooking into tortillas were examined. Samples from different stages during processing were tested for chemical composition and protein fractionation. The most prevalent type of kernel damage was mechanical, followed in decreasing order by molds, insects, heat, and rodent damage. Corn with higher content of damaged kernels was susceptible to overcooking, resulting in cracked or fully open nixtamal kernels and sticky masa that were difficult to handle during processing. Nutrient losses increased with increasing levels of kernel damage. Most nutrient losses from sound corn kernels occurred during washing as the pericarp and attached solids were removed. During simmering, damaged corn kernels were fully cooked into physically opened kernels with more nutrients being extracted into the water. About 15% of total solids and 50% of both crude fiber and fat were lost during cooking of corn with 30% kernel damage. The greatest losses were consistently observed for albumins and globulins from both sound and damaged kernels at all stages of cooking. Appropriate control of kernel damage level is required to improve yield of product with consistent quality. The susceptibility to overcooking of excessively damaged corn increases the complexity to consistently meet product quality specifications. Excess dry matter losses in the cooking liquor can significantly increase the risk of environmental contamination and cost of sewage water treatment.
Milled Rice Breakage Due to Environmental Conditions
Authors: Siebenmorgen T. J. , Nehus Z. T. , Archer T. R.
Published: June 2007

Milled, long‐grain rice was exposed to air at temperatures (T) of 20, 30, and 40°C, and relative humidities (RH) ranging from 25 to 85%. The kernels then were subjected to a breakage test to determine the extent of damage that occurred during each exposure condition. Increasing air T levels produced higher amounts of broken kernels across the RH range. Milled rice at higher moisture content (MC) levels sustained more extensive stress crack damage at low RH conditions and less stress crack damage at high RH conditions relative to milled rice at lower MC levels. Varietal differences were also present, but were overshadowed by MC effects.
Single‐Kernel Characteristics of Hard Winter Wheats in Relation to Milling and Baking Quality
Authors: Ohm J. B. , Chung O. K. , Deyoe C. W.
Published: June 2007

To investigate relationships of wheat single kernel (SK) characteristics with end‐use properties, we used 12 hard winter wheat cultivars harvested at six regions in Kansas in 1993. Significant positive correlations occurred among wheat hardness parameters including near‐infrared reflectance hardness score, SK hardness index (SK‐HI), and SK peak force (SK‐PF) obtained by the Single Kernel Characterization System (SKCS). The SKCS characteristics also were significantly correlated to conventional wheat quality parameters such as test weight, kernel density, and kernel sizing. Flour yields were significantly correlated with SK‐PF, SK‐HI, and SK weight (SK‐WT), suggesting the usefulness of SKCS in evaluating milling quality. The negative correlation of milling score with the standard deviation of SK‐HI and SK‐PF indicated that uniformity of SK hardness is desirable for good milling performance. However, bread loaf volumes had significant negative correlations with SK diameter and SK‐WT, mainly due to the inverse relationship between wheat protein contents and kernel weights or sizes. Loaf volume regression values, the changes in loaf volumes per one percentage point of flour protein, also had significant negative correlations with SK‐HI, SK‐PF, and SK‐WT.
Effect of Amaranthus and Buckwheat Proteins on Wheat Dough Properties and Noodle Quality
Authors: Bejosano Feliciano P. , Corke Harold
Published: June 2007

Isoelectric protein concentrates (IPC) were prepared from one buckwheat (Fagopyrum esculentum) and five Amaranthus genotypes. Their effect on the mixing properties of a wheat flour was studied. Mixograph and dynamic oscillatory measurements showed significant increases in dough strength with the addition of 2 and 4% IPC, correlated to the water‐insoluble fraction level of the IPC. The same IPCs were used at 2% level to supplement a wheat flour in making Chinese dry noodles. Measurable changes in both the raw and cooked noodle color were observed, and the change caused by addition of buckwheat IPC was substantial. Some of the IPCs caused an increase in cooking loss and only one caused an increase in weight, while increase in volume of the cooked noodles was not significantly affected. The changes in the rheological properties of cooked noodles due to addition of IPCs were measured. Overall, their effects were favorable, but the changes were statistically significant in only a few cases. The substantial dough‐strengthening effect of the IPCs was hence not effectively translated into improved cooked noodle quality, and possible reasons for this are discussed.
Effects of Processing Conditions and Sorghum Cultivar on Alkaline‐Processed Snacks
Authors: Suhendro E. L. , McDonough C. M. , Rooney L. W. , Waniska R. D. , Yetneberk S.
Published: June 2007

Sorghum (Sorghum bicolor (L.) Moench) grain was boiled or autoclaved in alkali, washed, drained, and dried into shelf‐stable half‐products (pellets). The pellets were deep‐fat fried to produce a crunchy snack product. Effects of cooking time, drying method (pellet moisture content), and sorghum cultivar on unfried and fried pellets were evaluated. Increasing the alkaline cooking time from 30 to 60 min decreased the yield of the pellets from 96 to 84% (on a dry weight basis). Cooked sorghum dried at room temperature (24°C) for 18 hr, followed by oven‐drying at 50°C for an additional 18 hr, produced pellets with a low moisture content (≤5%), that required a higher frying temperature (≥220°C). However, cooked sorghum dried at room temperature for 18 hr followed by oven‐drying at 50°C for 5 hr produced pellets with 9% moisture and a lighterdensity highly acceptable product when fried at 220°C. Fat content of fried pellets averaged 18%. The optimum method for producing a light, crunchy, fried product was cooking for 60 min, drying to 9% moisture, and frying at 220°C. ATx631*Tx436, the hardest endosperm‐texture sorghum used in the study, had the highest unfried and fried pellet yields. Dorado, an intermediate‐to‐soft endosperm‐texture sorghum, and ATx Arg‐1*Tx2907, a waxy sorghum, had lower yields. The fried pellets produced from Dorado and waxy sorghum (ATxArg‐1*Tx2907) were more expanded than those produced from ATx631*Tx436.
Effect of Puroindolines on the Breadmaking Properties of Wheat Flour
Authors: Dubreil Laurence , Méliande Sabine , Chiron Hubert , Compoint Jean‐Pierre , Quillien Laurence , Branlard Gérard , Marion Didier
Published: June 2007

The role of lipid‐binding proteins from wheat seed (puroindolines) on the breadmaking properties of wheat flour was investigated by determining the relationship between breadmaking quality and puroindoline content in samples of 32 wheat cultivars. An inverse relationship was mainly explained by the link between hardness and puroindoline contents. This link is in agreement with previous results which have shown a close structural identity between basic friabilins and puroindolines. Next, the effect of puroindolines in breadmaking was investigated by performing reconstitution experiments with two puroindoline‐free hard cultivars of opposite quality (Florence Aurore and Ecrin) as indicated in the screened wheat sample. Addition of 0.1% puroindolines to these flours drastically modified both the rheological properties of doughs and the structure of the bread crumb. Puroindolines are essential to the foaming properties of dough liquor, and a close relationship was found between the fine grain crumb provided by reconstituted flours with puroindolines and the fine structure of corresponding dough liquor foams. The effect of puroindolines on bread volume was mainly related to the rheological properties of wheat doughs.
Malting Oats: Effects on Chemical Composition of Hull‐less and Hulled Genotypes
Authors: Peterson David M.
Published: June 2007

Samples of hull‐less oat genotypes from the Cooperative Naked Oat Test grown in Ottawa, ON, and Aberdeen, ID, were analyzed for their potential as a food malt. Malted oats had a lower concentration of petroleum ether‐extractable lipid, but a much higher percentage of the lipid was in the form of free fatty acids. About 5% less starch and slightly more N was found in malted oats than in unmalted. Malted oats contained ≈8% soluble carbohydrate. During the germination phase of malting, nearly all the β‐glucan was degraded. α‐Amylase activity of malted oats approached that of malting barleys, but diastatic power was much lower. Groats of hulled cultivars grown at Madison, WI, were malted and analyzed with similar results. Because the increased levels of free fatty acids in the malted grains may lead to the development of rancid flavors, a method to curtail their increase or selections of genotypes with a minimum increase during malting may be necessary to produce a useful malted food product.
Neural Network Modeling of Physical Properties of Ground Wheat
Authors: Fang Qi , Biby Gerald , Haque Ekramul , Hanna Milford A. , Spillman Charles K.
Published: June 2007

Physical properties of ground materials from roller mills are affected by the characteristics of wheat and the operational parameters of the roller mill. Backpropagation neural networks were designed, trained, and tested for the prediction of three physical properties of ground wheat: geometric mean diameter (GMD), specific surface area increase (SSAI), and break release (BR). Eight independent variables were used as input data. Compared to conventional statistical models, the accuracy of prediction was improved substantially, as reflected by the significant reduction in root mean squared error (RMS), relative error (RE), and the increase in coefficient of determination R2 (>0.98). The neural network models are, therefore, capable of predicting the physical properties of the ground wheat.
Oxidative Cross‐Linking of Pentosans by a Fungal Laccase and Horseradish Peroxidase: Mechanism of Linkage Between Feruloylated Arabinoxylans
Authors: Figueroa‐Espinoza M. C. , Rouau X.
Published: June 2007

The potential of a laccase from the fungus Pycnoporus cinnabarinus to cross‐link feruloylated soluble wheat arabinoxylans was investigated using capillary viscometry, size‐exclusion HPLC, and reverse‐phase HPLC of phenolic compounds. The laccase results were compared with those for a hydrogen peroxide/horseradish peroxidase system. The oxidants provoked an increase in viscosity of a 0.2% (w/v) arabinoxylan solution. A gel was formed after 30 min with laccase. Hydrogen peroxide was consumed rapidly before a gel could be formed. Free ferulic acid, methyl ferulate, and vanillic acid inhibited the gelation, whereas fumaric acid had no effect. This suggests that the aromatic ring, and not the propenoic chain of ferulic acid, was the initiating site for arabinoxylan cross‐linking. Ferulic acid and its 8‐O‐4′, 8‐5′, and 5‐5′ dehydrodimers were present in nonoxidized arabinoxylans. Upon oxidation, the 8‐8′ and 8‐5′ benzofuran dehydrodimers appeared and the 8‐O‐4′ and 8‐5′ dimers increased. The production of dimers was proportional to the consumption of ester‐bound ferulic acid. In cross‐linked arabinoxylans, the major dimers were 8‐5′ benzofuran, 8‐8′, and 8‐O‐4′, whereas the 5‐5′ dehydrodimer remained at the same level as in the nonoxidized solution.
Formation of Resistant Starch by a Twin‐Screw Extruder
Authors: Unlu Emine , Faller James F.
Published: June 2007

The objective of this study was to evaluate the potential to increase the level of resistant starch (RS) in extruded products by optimizing extruder conditions. Three experiments were conducted as randomized complete block designs with two replicates. In the first experiment, corn starch, wheat starch, and potato starch were added at a level of 30% (w/w) to degerminated yellow corn meal to investigate the influence of starch type. In the second experiment, citric acid (CA) monohydrate was added to corn meal at levels of 0, 2.5, 5, and 7.5% (w/w). The third experiment was a full‐factorial arrangement to evaluate the effect of high‐amylose corn starch (HACS) level (0, 15, 30%, w/w) and CA level (0, 5, 7.5%, w/w) at two screw speeds (200 and 300 rpm). In the first experiment, the means for RS plus dietary fiber for the different starch formulations ranged from 1.27 to 2.28%. In experiment 2, adding CA increased RS plus dietary fiber content to a maximum of 5.23% at 7.5% CA. In the third experiment, the means for RS plus dietary fiber ranged from a low of 1.75% for 100% corn meal at 300 rpm to 14.38% for 7.5% CA and 30% HACS at 200 rpm. The results indicated a highly significant positive relationship between CA and RS formation and the same for amylose content. The RS formation had a negative relationship with screw speed, but the influence of screw speed was small when compared with that of CA and HACS.
Effect of Wheat Moisture Content on Meal Apparent Particle Size and Hardness Scores Determined by Near‐Infrared Reflectance Spectroscopy
Authors: Gaines Charles S. , Windham William R.
Published: June 2007

The AACC Approved Method for near‐infrared reflectance (NIR) spectroscopy to produce a wheat hardness score for wheat market classification can be corrected for variation in wheat moisture content. The cause of the variation in NIR spectra resulting from variation in wheat moisture was investigated. Ten samples each of soft red winter, soft white winter, hard red winter, and hard red spring wheats were stored at 20, 40, 60, and 80 equilibrium relative humidity. Wheats were then ground on a cyclone grinder as required by the standard method. Variation in unground wheat kernel moisture content resulted in variation in NIR data. NIR log 1/reflectance values increased at all wavelengths as wheat moisture content increased. Spectral changes were related to changes in the apparent particle size of ground wheat meal as it was influenced by moisture content. Higher moisture contents produced slightly higher apparent particle size in meal, suggesting larger particles of pericarp that became more pliable at higher moisture (temper) levels. The apparent particle size of meal of high moisture wheats resulted in greater NIR radiation scattering and decreased reflectance. Meal moisture content itself had no effect on the two NIR wavelengths used to evaluate wheat hardness.
Physical Properties of Extruded Strands of Hydroxypropylated Normal and High‐Amylose Corn Starch
Authors: Bae Sang Ouk , Lim Seung‐Taik
Published: June 2007

Normal (25% amylose) and high‐amylose (70% amylose) corn starches (CS and HA) were hydroxypropylated to 0.1 degree of molar substitution (MS) with propylene oxide in an alkaline‐ethanol medium (70% ethanol). CS and hydroxypropylated corn starch (HPCS) were mixed on dry basis with water and glycerol at a weight ratio of 7:2:1, and HA and hydroxypropylated high amylose corn starch (HPHA) were mixed at 7:3:1. Stearic acid, glycerol monostearate, or lecithin (3%, based on starch) was added to each mixture to examine the effects on the physical properties of the extrudate. The starch mixtures were extruded at high shear (100 rpm) to nonexpanded strands using a corotating twin‐screw extruder in a temperature range of 75–90°C. HA, alone and with all additives, showed lower die swelling in extrusion than did CS, whereas HPCS and HPHA showed higher die swelling than the corresponding unmodified starches. Water absorption of all HA extrudates was lower than those of all CS extrudates (22–35% and 68–97%, respectively, at 25°C). Hydroxypropylation increased the absorption for both starches. All extruded starches, regardless of additives, showed low solubility in water (0.1–1.0% for 2 hr at 25°C). Differential scanning calorimetry indicated that during extrusion, the lipid additives formed a helical complex with amylose in CS and HA, but weakly with HPCS and HPHA. The extruded strands of HA, alone and with additives, exhibited higher tensile and bending strengths (37.1–58.4 and 2.16–5.07 MPa, respectively), compared to the CS strands (12.5–59.3 and 1.06–4.10 MPa, respectively) at the same moisture content (7.5–8.5%). Both tensile strength and percent of elongation of the starch strands were reduced by the presence of a lipid additive. Hydroxypropylation increased elongation and flexibility of the extrudates. HPHA exhibited the greatest mechanical strength and flexibility among the tested starches.
Estimation of Fusarium Scab in Wheat Using Machine Vision and a Neural Network
Authors: Ruan Roger , Ning Shu , Song Aijun , Ning Anrong , Jones Roger , Chen Paul
Published: June 2007

A neural network was used to relate color and texture features of wheat samples to damage caused by Fusarium scab infection. A total of 55 color and texture features were extracted from images captured by a machine vision system. Random errors were reduced by using average values of features from multiple images of individual samples. A four‐layer backpropagation neural network was used. The percentage of visual scabby kernels (%VSK) estimated by the trained network followed the actual percentage with a correlation coefficient of 0.97; maximum and mean absolute errors were 5.14 and 1.93%, respectively. A comparison between the results by the machine vision‐neural network technique and the human expert panel led to the conclusion that the machine vision‐neural network technique produced more accurate determination of %VSK than the human expert panel.
Effect of Hydrophilic Plasticizers on Thermomechanical Properties of Corn Gluten Meal
Authors: di Gioia Lodovico , Cuq Bernard , Guilbert Stéphane
Published: June 2007

The glass transition temperature and rheological moduli of plasticized corn gluten meal (CGM) were determined with dynamic mechanical thermal analysis (DMTA). The tested plasticizers were water, glycerol, polyethylene glycols (PEG) 300 and 600, glucose, urea, diethanolamine, and triethanolamine, at concentrations of 10–30% (dwb). The glass transition temperature (Tg) of CGM, measured at 188°C when unplasticized, was lowered by >100°C at 30% plasticizer content, except by PEG 600 and glucose, which showed limited compatibility with CGM proteins. The highest plasticizing efficiency, on a molar basis, was measured with PEG 300 and was attributed to the large number of hydrophilic groups and the high miscibility of this compound with CGM proteins. The change in Tg due to the plasticizing effect was modeled with the Gordon and Taylor equation, but a better fit of the experimental data was obtained with the Kwei equation.
Physicochemical Properties of Zero Amylose Hull‐less Barley Starch
Authors: Zheng G. H. , Han H. L. , Bhatty R. S.
Published: June 2007

Zero amylose starch isolated from hull‐less barley (HB) showed a typical A‐type diffraction pattern. The X‐ray analysis suggested that granules of zero amylose (SB94794) and 5% amylose (CDC Candle) HB starches had lower crystallinity than did commercial waxy corn starch. Differential scanning calorimetry showed lower transition temperatures and endothermal enthalpies for the HB starches than for the waxy corn starch. The zero amylose HB starch showed a Brabender pasting curve similar to that of waxy corn starch, but with lower pasting and peak temperatures and a higher peak viscosity. Noteworthy characteristics of zero amylose HB starch were its low pasting temperature and high paste clarity and freezethaw stability, which make this starch useful for many food and industrial applications.
Role of Hydrogen Peroxide Produced by Baker's Yeast on Dough Rheology
Authors: Liao Yue , Miller R. A. , Hoseney R. C.
Published: June 2007

Baker's yeast, Saccharomyces cerevisiae, has a well‐known effect on dough rheology during breadmaking. During a 3‐hr fermentation, hydrogen peroxide (H2O2) produced by yeast (0.76%, fwb) increased from 1.09 to 2.32 μmol/g of flour. The spread test, a measure of a dough's rheological properties, showed that yeast had an effect on dough rheology similar to that of H2O2, an oxidant that makes flour‐water dough more elastic. In additional experiments (spread test and H2O2 measurement), glucose oxidase, an enzyme that produces H2O2, gave results similar to those with yeast. The fact that catalase, an enzyme that destroys H2O2, reversed the rheological effect of added H2O2 but did not reverse the effect of either yeast or glucose oxidase suggested that either wheat flour contains an inhibitor to catalase or H2O2 was not the active component. A series of experiments, including use of defatted flour, remixing, and mixing dough under nitrogen, all indicated that catalase was inhibited by peroxides in the lipid fraction of flour. These results also suggested that H2O2 is responsible for the effects of yeast and glucose oxidase on dough.
Gelatinization Profiles of Triticale Starch in Cookies as Influenced by Moisture and Solutes
Authors: Leon A. E. , Jovanovich G. , Añón M. C.
Published: June 2007

Starch physicochemical parameters and phase transitions were determined in flours of 10 advanced lines and cultivars of triticale (Cananea, Currency, Eronga, LA 24 Bve, LA 20 FCA, LA 83 FCA, Tatú, Tehuelche, Quiñé, and Yagan). Starch behavior was also analyzed during the baking of cookies prepared with triticale flours. Starch granule size, crystal type patterns, and size distribution were determined by light microscopy, X‐ray diffraction, and gel‐permeation chromatography, respectively. Two types and sizes of starch granules with characteristic A‐form crystals were obtained in all samples tested. The Quiñé cultivar showed the lowest extent of starch crystallinity. Only a monophasic endotherm was found by differential scanning calorimetry for water content >50–60%. Gelatinization temperature and enthalpy values varied significantly among samples. A biphasic endotherm was detected for water contents between 35 and 60%, and no endothermic transitions were observed for water levels <35%. Only one endotherm corresponding to starch gelatinization was detected in baked cookies prepared with five triticale flours. In all samples, the highest enthalpy of gelatinization of starch was detected for the cookie surface, whereas the highest gelatinization temperature was observed for the center. These differences may be attributed to the presence and content of the solutes in cookie dough and also to the degree of starch gelatinization during the cooking process.