bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Variance for Gluten Strength Contributed by High Molecular Weight Glutenin Proteins
Authors: Radovanovic N. , Cloutier S. , Brown D. , Humphreys D. G. , Lukow O. M.
Published: June 2007

A total of 162 doubled haploid (DH) lines were produced from a cross between Triticum aestivum L. ‘AC Karma’ and line 87E03‐S2B1 to study the genetic contribution of high molecular weight (HMW) glutenin subunits to gluten strength. HMW glutenin subunit composition of each DH line was determined by SDS‐PAGE. The population was grown in the field at one location in 1999 and at three locations in 2000. Gluten strength and dough mixing properties were measured by mixograph test and SDS‐sedimentation test. Variance components were estimated for each measurement to determine the variability contributed by HMW glutenin subunits. Results indicated significant environmental impact on tested mixograph parameters, SDS‐sedimentation volumes and grain and flour protein concentration. Significant main effects of Glu‐1D loci encoded subunits were obtained for mixograph development time, energy to peak, slope after peak, and first minute slope. Lines containing 5+10 combination of subunits had higher values for mixograph development time and energy to peak, while slope after peak and first minute slope were lower as compared with 2+12 containing lines. Low intergenomic interactions were observed for bandwidth energy (BWE), total energy (TEG), and SDS‐sedimentation test, involving B and D genomes only. A portion of the genetic variability for gluten strength was accounted for overexpression of Bx7 subunit originating from the cultivar Glenlea derived line 87E03‐S2B1. There was no significant effect of Glu‐A1 encoded subunits on any of the tested parameters. Estimated genetic variability for gluten strength contributed by Glu‐B1 and Glu‐D1 encoded HMW glutenins was 55% for mixing development time and 51% for energy to peak.
Assessing Environmental Influences on Solvent Retention Capacities of Two Soft White Spring Wheat Cultivars
Authors: Guttieri Mary J. , McLean Reuben , Lanning Susan P. , Talbert Luther E. , Souza Edward J.
Published: June 2007

The solvent retention capacity test (SRC) (AACC Approved Method 56‐11) of flour is used to evaluate multiple aspects of wheat (Triticum aestivum L.) quality including pentosan content, starch damage, gluten strength, and general water retention based on the ability of flour to retain a range of solvents. The objectives of this study were to evaluate the effects of grain production environment in general and crop irrigation and fertility management in particular on SRC of soft wheat flour, and to evaluate the ability of SRC to predict end‐use quality across diverse environments. Two soft white spring wheat cultivars ‘Pomerelle’ and ‘Centennial’ were produced in a range of irrigated and rain‐fed production environments. SRC profiles and milling and baking quality parameters were measured. In a two‐year study at Aberdeen, ID, with two late‐season irrigation management regimes and two crop nitrogen fertility treatments, only wheat genotype significantly affected flour SRC. In two‐year studies at Tetonia, ID, one conducted under rain‐fed conditions and the other under irrigation, additional fertilizer applied at anthesis did not affect SRC. Correlations among quality parameters were determined using the Aberdeen and Tetonia flour samples, as well as samples of the same genotypes grown in fertility trials under rain‐fed conditions at Havre and Bozeman, MT, and under irrigation at Bozeman. Patterns of correlations among SRC values were similar for both genotypes. Grain test weight was negatively correlated with sodium carbonate and sucrose SRC of both genotypes. Flour protein was strongly positively correlated with sucrose and lactic acid SRC of both genotypes. The optimal regression models for predicting sugar snap cookie diameter (AACC Approved Method 10‐52) as a function of protein, SRC, flour extraction, and kernel hardness were different for the two cultivars. SRC evaluations of flours from these trials were consistent with large genotype and environment effects, yet minimal genotype × environment interaction. This suggests that selection among genotypes within an environment will produce a gain‐from‐selection observable in multiple and diverse environments.
Selective Nixtamalization of Fractions of Maize Grain (Zea mays L.) and Their Use in the Preparation of Instant Tortilla Flours Analyzed Using Response Surface Methodology
Authors: Martín‐Martínez E. San , Jaime‐Fonseca M. R. , Martínez‐Bustos F. , Martínez‐Montes J. L.
Published: June 2007

Using a continuous decorticating machine, white dent corn was efficiently separated, after brief steeping in water, into two fractions: the first (12.5%) consisting mainly of pericarp, germ, and tip cap (PGT); the second (87.5%) consisting of endosperm. Nixtamalization of the maize fractions in the presence of 0.6% (w/w) lime caused an increase in the hot‐paste viscosity at 90°C, while nixtamalization of PGT at lime inputs <0.6% (w/w) resulted in decreased viscosity. Three domains were found for the viscosity of nixtamalized endosperm at 90°C: lower concentrations of lime (< 0.15%, w/w) resulted in lower viscosity values; increased lime (0.15% – <0.3%, w/w) increased the viscosity values; and a lime concentration of 0.3% (w/w) resulted in a lower viscosity value. The response variables (water absorption index, water solubility index, initial viscosity, and viscosity at 90°C for nixtamalized PGT, and compression force and compression area of tortillas) indicated that the mathematical models fit the experimental data and the variance of the models was highly significant. Tortillas of good functional characteristics similar to tortillas produced by the traditional process were obtained when 5% nixtamalized fractions of PGT were blended with 95% nixtamalized endosperm.
Comparison of Near‐Infrared Reflectance Spectroscopy and Texture Analyzer for Measuring Wheat Bread Changes in Storage
Authors: Xie Feng , Dowell Floyd E. , Sun Xiuzhi S.
Published: June 2007

Bread staling affects bread texture properties and is one of the most common problems in bread storage. Bread firmness, as measured in compression mode by a texture analyzer (TA) has been commonly used to measure bread staling. This study investigated the potential of visible and near‐infrared reflectance spectroscopy (NIRS) to detect bread changes during storage by comparing NIRS results with those obtained by TA. Twenty‐five loaves of commercial wheat white pan bread from one batch were studied over five days. NIRS and TA measurements were made on the same slice at approximately the same time. The experiment was repeated five times using the same kind of commercial samples from five different batches. NIRS measurements of slices, loaf averages, and daily averages were compared with TA measurements. NIRS spectra had a high correlation to TA firmness. NIRS measurements correlated better with the actual storage time and had smaller standard deviations than the TA measurements. The batch differences had less effect on NIRS measurements than on the TA measurements. The results indicate that NIRS could follow bread changes during storage more accurately than the TA. NIRS is probably based on both physical and chemical changes during bread staling, unlike the TA method that only measures bread firmness, which is only one aspect of the staling phenomenon.
Properties of Flours and Starches as Affected by Rough Rice Drying Regime
Authors: Patindol James , Wang Ya‐Jane , Siebenmorgen Terry , Jane Jay‐lin
Published: June 2007

Flours and starches from rough rice dried using different treatment combinations of air temperature (T) and relative humidity (RH) were studied to better understand the effect of drying regime on rice functionality. Rough rice from cultivars Bengal and Cypress were dried to a moisture content of ≈12% by three drying regimes: low temperature (T 20°C, RH 50%), medium temperature (T 40°C, RH 12%), and high temperature (T 60, RH 17%). Head rice grains were processed into flour and starch and evaluated for pasting characteristics with a Brabender Viscoamylograph, thermal properties with differential scanning calorimetry, starch molecular‐size distribution with high‐performance size‐exclusion chromatography (HPSEC), and amylopectin chain‐length distribution with high‐performance anion‐exchange chromatography with pulsed amperometric detection (HPAEC‐PAD). Lower head rice and starch yields were obtained from the batch dried at 60°C which were accompanied by an increase in total soluble solids and total carbohydrates in the pooled alkaline supernatant and wash water used in extracting the starch. Drying regime caused no apparent changes on starch molecular‐size distribution and amylopectin chain‐length distribution. Starch fine structure differences were due to cultivar. The pasting properties of flour were affected by the drying treatments while those of starch were not, suggesting that the grain components removed in the isolation of starch by alkaline‐steeping were important to the observed drying‐related changes in rice functionality.
Wheat Flour Proteins as Affected by Transglutaminase and Glucose Oxidase
Authors: Rosell C. M. , Wang J. , Aja S. , Bean S. , Lookhart G.
Published: June 2007

Enzymes are good tool to modify wheat proteins by creating new bonds between the protein chains. In this study, the effect of the addition of glucose oxidase (GO) and transglutaminase (TG) on the wheat flour proteins is presented. The modification of wheat proteins was determined by analyzing the changes in gluten quality, alveograph parameters, and protein modifications. The amount of wet gluten increased with the addition of GO and TG, but the gluten quality was not improved in any case. Regarding the alveograph parameters, the effect of GO was readily evident obtaining wheat dough with higher tenacity and lower extensibility than the control, while TG led to doughs with lower tenacity and that were also less extensible. The protein modifications were characterized by free‐zone capillary electrophoresis (FZCE). FZCE data indicated that TG polymerizes mainly glutenins and, of those, the high molecular weight glutenin subunits were the most affected.
Variability in Starch Acetylation Efficiency from Commercial Waxy Corn Hybrids
Authors: Wilkins M. R. , Wang P. , Xu L. , Niu Y. , Tumbleson M. E. , Rausch K. D.
Published: June 2007

Raw material variability is common for starch processors and is responsible for increased processing costs. In this study, variability of starch acetylation due to hybrid influence was quantified. Six waxy corn (maize) hybrids from 1998 and five waxy corn hybrids from 1999 were wet‐milled in the laboratory. Starch obtained from each hybrid was modified according to a laboratory‐scale acetylation procedure. To evaluate reaction efficiency, reaction rate, acetyl content, pH, and amount of NaOH used were recorded for each reaction. After modification, a Rapid Visco Analyser (RVA) was used to characterize modified starches and determine differences in modified starches from different hybrids. Using the same acetylation protocol, reaction efficiencies were observed at 47–73%. Reaction efficiencies were significantly lower for 1998 hybrids (50.0%) compared with the efficiency observed for the same hybrids grown in 1999 (62.7%). Acetylated starch from 1999 had increased peak, trough and final viscosities and increased reaction efficiency as compared with acetylated starch from 1998. Differences in setback were observed among 1998 hybrids for acetylated samples. Differences in trough and final viscosity were observed among 1999 hybrids for acetylated and native (unmodified) samples. Differences in breakdown among 1999 hybrids also were observed for native samples.
Variability of Reaction Efficiencies and Pasting Properties of Acetylated Dent Corn Starch from Various Commercial Hybrids
Authors: Wilkins M. R. , Wang P. , Xu L. , Niu Y. , Tumbleson M. E. , Rausch K. D.
Published: June 2007

Genetic diversity in corn (maize) has contributed to variability in corn processing characteristics. Differences in acetylated dent corn starch pasting properties and reaction efficiencies due to hybrid were assessed. Ten dent corn hybrids grown during 1998 and nine dent corn hybrids grown during 1999 were wet‐milled in the laboratory. Starch from each hybrid was modified using a laboratory‐scale acetylation procedure. NaOH consumed and reaction time were recorded for each reaction. A Rapid Visco Analyser (RVA) was used to measure starch pasting properties. Acetyl content was measured by a spectrophotometric method, from which reaction efficiency was calculated. Reaction efficiencies were observed at 35–56%. Overall reaction efficiencies for starch samples from 1998 hybrids were lower than samples from 1999 hybrids. Differences in peak viscosity, trough viscosity, final viscosity, setback, and pasting temperature were found among 1998 hybrids. Differences in trough viscosity, final viscosity, and breakdown were found among 1999 hybrids.
Physiological Responses of Men and Women to Barley and Oat Extracts (Nu‐trimX). II. Comparison of Glucose and Insulin Responses
Authors: Hallfrisch Judith , Scholfield Daniel J. , Behall Kay M.
Published: June 2007

This study was designed to compare the glucose, insulin, and glucagon responses to consumption of high‐soluble β‐glucan compounds from oats and barley. After an initial medical evaluation that included blood and urine testing, 11 men and 11 women, nondiabetics, 35–57 years, were selected. Subjects consumed a controlled diet for three days. On the third day of five successive periods, subjects consumed 1 g/kg of body weight of carbohydrate as glucose or 0.66 g/kg of body weight pudding (predominantly sucrose) and 0.33 g/kg of body weight as oat bran, barley flour, oat or barley extract (Nu‐trimX) in a Latin square design. Order of treatment was randomly assigned. Glycemic responses were calculated using the trapezoid method. Data were analyzed using mixed procedure analysis of variance program. Glucose responses to oats, barley, and both extracts, and areas under the curve were significantly lower than responses to the glucose solution (P < 0.0001). Insulin responses for the barley extract were lowest and were significantly lower than for glucose solution. Oat and barley extracts retain the beneficial effects of the grains from which they are extracted. High‐soluble fiber barley is more effective than standard oats. Oat and barley carbohydrate‐based fat substitutes can provide a useful addition to menus to control plasma glucose responses.
Probiotics and Prebiotics
Authors: Tomasik Przemyslaw Jan , Tomasik Piotr
Published: June 2007

Probiotics, bacteria from the genera Bifidobacterium and Lactobacillus, and yeast, Saccharomyces, as well as prebiotics belonging to the group of dietary fiber (inulin with low degree of polymerization, fructose‐derived oligosaccharides, and resistant starch) are natural factors useful in prophylaxis and therapy of several common diseases including some types of cancer. They are available commercially and can be introduced to produce so‐called functional food. Probiotics and prebiotics can be utilized either separately or jointly (as synbiotics or eubiotics). Mechanisms of both biotics are discussed. The role of cereals in probiosis is considered. Possibilities for extension of the uses of the original Chinese probiotic, chaw tofu, are also considered.
Pretreatment of Wet‐Milled Corn Fiber to Improve Recovery of Corn Fiber Oil and Phytosterols
Authors: Singh Vijay , Johnston David B. , Moreau Robert A. , Hicks Kevin B. , Dien Bruce S. , Bothast R. J.
Published: June 2007

The phytosterol‐containing oil in the corn fiber (corn fiber oil) has potential use as a natural low‐density lipoprotein (LDL) lowering nutraceutical but its low concentration (1–3%) makes it difficult and expensive to extract. Pretreatment of corn fiber with dilute acid or glucosidases removed nonlipid components of fiber, producing oil‐enriched fractions that should be more amenable to efficient and inexpensive oil extraction. Acid, as well as enzymes, significantly increased the content of corn fiber oil and its phytosterol compounds by hydrolyzing (and removing) the starch and nonstarch (cell wall) polysaccharides from the wet‐milled corn fiber. Dual treatment of the fiber with acid and enzyme greatly increased the concentrations of corn fiber oil and its phytosterol components, compared with acid or enzyme treatments alone. Depending on the treatment, the oil concentration in the residual solids increased from 0.3 to 10.8% (21–771% increase in conc.) and the total phytosterol concentration increased from 19.8 to 1256.2 mg/g of fiber (11–710% increase in conc.) compared with untreated fiber.
Purification and Analysis of Wheat Grain Polyphenol Oxidase (PPO) Protein
Authors: Anderson James V. , Morris Craig F.
Published: June 2007

Wheat (Triticum aestivum L.) breeding programs have used various whole kernel assays to estimate polyphenol oxidase (PPO) activity, thereby identifying germplasm that has a greater chance of producing consumer products with superior color. However, the enzymes involved in these assays are poorly understood and the purification and characterization of a wheat kernel PPO protein has not been reported previously. A PPO from wheat bran was purified using ammonium sulfate precipitation, ion and size‐exclusion chromatography, and continuous elution electrophoresis. The purified protein migrated at 67 kDa on SDS‐PAGE under denaturing and reducing conditions, exhibited PPO activity in the presence of SDS, and eluted at 45 kDa on SDS‐PAGE under nondenaturing and nonreducing conditions. N‐terminal sequence analysis of peptide fragments obtained from tryptic digests confirmed the purified wheat bran protein as a PPO. This wheat PPO protein showed the greatest sequence identity to grape (Vitis vinifera) and pineapple (Ananas comosus) PPO. The purified wheat PPO shares no more sequence identity with the deduced amino acid sequence of a previously isolated partial wheat PPO sequence than it does to PPO from other plant taxa widely divergent from wheat. Based on immunoblot analysis, purified PPO from wheat bran appears to be a processed, mature form lacking an estimated 14–16 kDa transit peptide required for plastid localization.
Influence of High‐Temperature Drying on Structural and Textural Properties of Durum Wheat Pasta
Authors: Zweifel C. , Handschin S. , Escher F. , Conde‐Petit B.
Published: June 2007

Starch and protein are the main polymeric ingredients of pasta and they determine the structural and textural properties of cooked pasta. The present investigation sought better understanding of the impact of high‐temperature (HT) drying on the starch and the protein fraction, and their role in structure and texture of pasta. Durum wheat spaghetti was prepared in a pilot‐plant installation. The drying conditions were selected for the HT phase at 80 or 100°C applied at high, intermediate, or low product moisture content. Spaghetti dried at 55°C served as a reference sample. The color of dry pasta was measured and the changes in the starch and protein fractions were determined by protein solubility, light microscopy, confocal scanning laser microscopy (CSLM), cooking tests, and texture measurements. HT drying at 100°C and low product moisture promoted browning of pasta. At the molecular level, HT drying promoted protein denaturation. At the microscopic level, HT drying contributed to a better preservation of the protein network and reduced swelling of starch and disintegration of granules. At the macroscopic level, HT drying enhanced the firmness of cooked pasta and reduced surface stickiness. In general, the changes were more pronounced by increasing the drying temperature from 80 to 100°C and by shifting the HT phase from an early to a late stage of the drying process. The drying conditions are determinant for the phase morphology of protein and starch in cooked pasta which, in turn, govern the textural properties of pasta.
Amyloplast Formation and Starch Granule Development in Hard Red Winter Wheat
Authors: Bechtel Donald B. , Wilson Jeff D.
Published: June 2007

Plastids in the coenocytic endosperm of young wheat caryopses were mostly in the form of pleomorphic proplastids with a few of the plastids containing small starch granules. Following cellularization of the coenocytic cytoplasm, the outer one or two endosperm cell layers became meristematic and continued to divide until about 14 days after flowering (DAF). During the first week of endosperm development, newly divided cells had plastids that were pleomorphic in shape, while subaleurone cells interior to the meristematic region contained amyloplasts that contained a single‐size class of starch granules (incipient A‐type starch granules). The pleomorphic plastids exhibited tubular protrusions that extended a considerable distance through the cytoplasm. Amyloplasts in cells interior to the meristematic region did not exhibit protrusions. Both subaleurone and central endosperm cells had amyloplasts that exhibited protrusions at 10–12 DAF, and some of the protrusions contained small starch granules (incipient B‐type starch granules). Protrusions were not observed in endosperm amyloplasts at 14 DAF. Two sizes of starch, large A‐type and smaller B‐type granules were present within the cells, however. Amyloplast protrusions were numerous again at 17 DAF in both subaleurone and central endosperm cells; at 21 DAF, a third size class of small C‐type starch granules was observed in the cytoplasm. Amyloplasts in the endosperm of wheat apparently divided and increased in number through protrusions because binary fission typical of plastid division was never observed. Protrusions were observed in the coenocytic cytoplasm, in dividing cells, in subaleurone and central endosperm cells at 10–12 DAF, and in subaleurone and central endosperm cells at 17 DAF. The results suggest that there are three sizes of starch granules produced at specific times during wheat endosperm development.
Starch Characteristics of the Rice Mutant du2‐2 Taichung 65 Highly Affected by Environmental Temperatures During Seed Development
Authors: Suzuki Yasuhiro , Sano Yoshio , Ishikawa Tetsuya , Sasaki Tomoko , Matsukura Ushio , Hirano Hiro‐Yuki
Published: June 2007

The effects of environmental temperature (21 vs. 28°C) during rice seed development on the starch characteristics (apparent amylose content, amylopectin chain length distribution, and gelatinization properties) of nonwaxy Taichung 65 (T65), waxy Taichung (T65wx), du2‐2 mutated low‐amylose strain Taichung (76‐3/T65), and Koshihikari were studied. Amylose contents increased with decreasing environmental temperatures. Analysis of the amylopectin chain length distribution showed that the relative amounts of long chains with degree of polymerization (DP) > 25 in all starches decreased if maturation occurred at 21°C. Gelatinization onset, peak, and conclusion temperatures and enthalpies decreased with decreasing environmental temperatures. Of all starches studied, the du2‐2 mutated low‐amylose Taichung (76‐3/T65) was most affected by maturation temperatures. These results indicate that the du2‐2 mutated low‐amylose Taichung (76‐3/T65) may be a useful strain in understanding biochemical and genetic starch biosynthesis response to slight changes in temperature.
Effects of Nitrogen Fertilizer on Protein Quantity and Gluten Strength Parameters in Durum Wheat (Triticum turgidum L. var. durum) Cultivars of Variable Gluten Strength
Authors: Ames N. P. , Clarke J. M. , Dexter J. E. , Woods S. M. , Selles F. , Marchylo B.
Published: June 2007

Field studies were conducted over three years at two locations in Saskatchewan, Canada, to determine the effect of nitrogen fertilizer on protein quantity and protein strength in 10 cultivars of durum wheat (Triticum turgidum L. var. durum) representing a range of gluten strength. Increasing nitrogen fertilizer resulted in increased protein content in all cultivars across environments. Cultivars were clearly differentiated on the basis of gluten strength using a gluten index (GI), SDS sedimentation (SDSS), alveograph indices of overpressure (P) and deformation energy (W), mixograph energy to peak (ETP), and mixograph bandwidth energy (BWE) at all fertilizer levels. Variable cultivar response to nitrogen fertilizer was observed only for protein content, GI, and alveograph W. The nature of the cultivar‐by‐fertilizer interaction for GI suggested that the conventional strength cultivars would benefit more from nitrogen fertilizer than the extra‐strong types, which showed no change or slight decreases in GI with nitrogen fertilizer despite an increase in total gluten. SDSS increased with nitrogen fertilizer, following similar trends as protein. Gluten strength rankings of the cultivars by SDSS were maintained with increased fertilizer. Fertilizer had little effect on alveograph P, mixograph ETP, and mixograph BWE. Overall, GI values were more stable across increasing levels of nitrogen fertilizer and resultant increased protein content compared with SDSS, mixograph development time, and alveograph W and L, suggesting it is a good test for estimating intrinsic gluten strength for cultivars with a wide range of protein content.
Effects of Modified Processing Conditions on Oxidative Properties of Semolina Dough and Pasta
Authors: Borrelli G. M. , De Leonardis A. M. , Fares C. , Platani C. , Di Fonzo N.
Published: June 2007

During pasta making, semolina is subject to various modifications that are mainly related to oxidative activities with relative effects on some of its components. To evaluate the involvement of hydroperoxidation and bleaching of lipoxygenase (LOX) and peroxidase (POD) activities on loss of pigments and ‐SH groups, their behavior in semolina and during processing was analyzed. Processing was done in standard and four experimental conditions, applying chemical (pH 5.0 and 8.0) and physical (10 and 40°C) treatments, during the mixing and extrusion phases, to study their effects on components. Results pointed out that treatments principally affected hydroperoxidation and bleaching activities of LOX rather than the POD. During pasta making, enzymatic activities showed the same trend in all cultivars, and this was reproducible in all the experimental conditions. Temperature effects on preservation of components were modest, whereas pH 8.0 improved the residual pigment and ‐SH group content in pasta, probably because of the concomitant reduction of oxidative enzyme levels. Finally, out of the four investigated wheat cultivars, Cosmodur showed the best performance in the experimental conditions applied. In fact, high pigment content and yellow index associated with low oxidative activity levels in semolina and in processing samples resulted in better pasta color. Such findings have confirmed that breeding and technological approaches may play an important role in the control of oxidative activities during pasta making, preserving the constituents that positively influence the final pasta color.
Relationship Between the Qualitative and Quantitative Compositions of Gluten Protein Types and Technological Properties of Synthetic Hexaploid Wheat Derived from Triticum durum and Aegilops tauschii
Authors: Wieser Herbert , Hsam Sai L. K. , Zeller Friedrich J.
Published: June 2007

The contribution of the diploid wheat species Aegilops tauschii (Coss.) Schmall to the technological properties of bread wheat (Triticum aestivum L.) was previously studied by the investigation of synthetic hexaploids derived from tetraploid durum wheat (T. turgidum L.) and three diploid Ae. tauschii lines. The results indicated that bread volume, gluten index, SDS‐sedimentation volume, and maximum resistance of gluten were significantly influenced by the Ae. tauschii lines. To determine the relationship between technological properties and qualitative and quantitative compositions of gluten proteins, the flours of parental and synthetic lines were extracted using a modified Osborne fractionation. Gliadin and glutenin fractions were then characterized by reversed‐phase (RP) HPLC on C8 silica gel. The HPLC patterns revealed typical differences between synthetic and parental lines. The gliadin patterns of three synthetic lines and the glutenin patterns of two synthetic lines were more similar to that of the diploid Ae. tauschii parents involved in the hybrids. In the glutenin pattern of one synthetic line, characteristics from both Ae. tauschii and the durum wheat parents were observed. The amount of total gliadin and gliadin types of the synthetic lines was mostly intermediate between those of the durum and Ae. tauschii parents. The amounts of total glutenin and glutenin types (HMW and LMW subunits) of the synthetic lines were generally higher than those of the parental lines, and the ratio of gliadins to glutenins was significantly decreased. High positive correlations were found between the amount of total glutenins, HMW, and LMW subunits and bread volume, maximum resistance and extension area of gluten, and SDS‐sedimentation volume. The ratio of gliadins to glutenin subunits had a strong negative influence on these properties. The protein content of the flours and the amount of total gluten proteins were not correlated with any of the technological properties. Results on the relationship between biochemical characteristics and the breadmaking properties indicated that wheat prebreeding would benefit from studies on protein types and quantification in the choice of parents. In addition, the potential of the diploid Ae. tauschii for improvement of breadmaking quality should be further exploited.
Solid‐Phase Microextraction Method for Headspace Analysis of Volatile Compounds in Bread Crumb
Authors: Ruiz J. A. , Quilez J. , Mestres M. , Guasch J.
Published: June 2007

A solid‐phase microextraction method was developed to analyze volatile compounds in bread crumb. Three different fibers usually used to determine volatile compounds in foodstuffs were tested, and Carboxen/ Polydimethylsiloxane showed the best extraction efficiency. This method can determine ≈65 compounds, although only the main compounds responsible for the crumb aroma profile (6 alcohols, 5 aldehydes, 5 acids, and 2 ketones) were evaluated quantitatively with a relative standard deviation <20% and limits of detection were 1–18 mg/kg. All the compounds showed a good linearity in concentration ranges of interest with acceptable correlation coefficients (r > 0.99) and recoveries close to 100%. The optimized solid‐phase microextraction (SPME) method was applied to determine aromatic compounds in some precooked frozen breads marketed in Spain (baguettes and ciabattas).
Effect of Hydroxypropylation on Retrogradation and Water Dynamics in Wheat Starch Gels Using 1H NMR
Authors: Choi S. G. , Kerr W. L.
Published: June 2007

The water dynamics in gels made from native wheat starch, control (alkali‐treated) starch, and hydroxypropylated starch were studied using 1H NMR relaxometry. Transverse relaxation studies showed that at least two domains of water exist in the starch gel, one with a T2 of 0.5–8 msec and one with a T2 at 8–200 msec. For starch gels held at 5°C for up to 15 days, the peak T2 of both regions decreased with time for gels made from native starch, but not for those made from hydroxypropylated starch. Changes in integrated signal in each region suggests that water migrates out of the lower T2 domain during retrogradation. Gels made from isolated amylose had a single, relatively mobile water domain, with T2 dependent on gel concentration. This fraction did not change during storage at 5°C. Granule‐rich gels showed two water domains, one with a T2 range similar to that for amylose gels, which varied over time and were thermally reversible. During storage, most significant changes occurred in the relatively low T2 region associated with granule remnants. These studies show that, in addition to changes in starch during retrogradation, water dynamics are also affected by recrystallization and chemical modification of starch molecules.
Protein Quality of Wheat Desirable for Making Fresh White Salted Noodles and Its Influences on Processing and Texture of Noodles
Authors: Park Chul Soo , Hong Byung Hee , Baik Byung‐Kee
Published: June 2007

Protein characteristics of wheat flours from various wheat classes, and of commercial flours for making noodles, were evaluated to determine the effects of protein content and quality on processing and textural properties of white salted noodles, as well as to identify protein quality required for making white salted noodles. SDS sedimentation volume based on constant protein weight, mixograph mixing time, and proportions of salt‐ and alcohol‐soluble protein of three commercial flours for making noodles were more similar to those of hard wheat than to soft wheat flours. SDS sedimentation volume of commercial flours for making noodles based on constant protein weight ranged from 38.5 to 40.0 mL and was higher than those of most soft wheat flours. Mixograph mixing time and proportion of salt‐soluble protein of hard and commercial flours for making noodles were >145 sec and mostly <13.8%, respectively, while those of club and soft wheat flours were < 95 sec and >15.0%. Both protein content and protein quality, as determined by SDS sedimentation volume based on constant protein weight, mixograph mixing time, proportion of salt‐soluble protein, and score of HMW‐GS compositions correlated with optimum water absorption of noodle dough and hardness of cooked white salted noodles.
Structural Changes of Debranched Corn Starch by Aqueous Heating and Stirring
Authors: Han J.‐A. , BeMiller J. N. , Hamaker B. , Lim S.‐T.
Published: June 2007

Aqueous dispersions (2 mg/mL) of debranched corn starches of different amylose contents (waxy, normal, and high‐amylose) were subjected to extensive autoclaving and boiling‐stirring, and then the changes in starch chain profile were examined using medium‐pressure, aqueous, size‐exclusion column chromatography. As autoclaving time increased from 15 to 60 min, weight‐average chain length (CLw) of waxy, normal, and high‐amylose corn starches determined using pullulan standards decreased from 46 to 41.2, from 122.1 to 96.3, and from 207.3 to 151.8, respectively. Number‐average chain length (CLn) measured by the Nelson‐Somogyi method also decreased from 23.0 to 18.4, from 26.4 to 21.8, and from 66.5 to 41.5, respectively, indicating that thermal degradation of starch chains occurred. The CLw/CLn ratio for normal corn starch was higher than that for waxy corn starch, indicating an increase in polydispersity of the amylose fraction. Thermal degradation was also observed when the debranched starch was subjected to the boiling‐stirring treatment (0–96 hr). During 96 hr, the CLw and relative proportion of B≥2 chains of amylopectin released by debranching waxy corn starch increased, whereas those of B1 chains decreased. This change may indicate physical aggregation of B1 chains. But branches from normal and high‐amylose corn starches showed increases in CLw and the proportion of both B1 and B≥2 chains, along with substantial decreases in those of amylose chains. Therefore, thermal degradation of amylose was greater than that of amylopectin.
Levels of Avenanthramides and Activity of Hydroxycinnamoyl‐CoA:Hydroxyanthranilate N‐Hydroxycinnamoyl Transferase (HHT) in Steeped or Germinated Oat Samples
Authors: Bryngelsson Susanne , Ishihara Atsushi , Dimberg Lena H.
Published: June 2007

Concentrations of avenanthramides and activity of the biosynthetic enzyme hydroxycinnamoyl‐CoA:hydroxyanthranilate N‐hydroxycinnamoyl transferase (HHT) were analyzed in dry or, steeped nonmilled or milled, non‐heat‐treated (raw) or heat‐treated oat samples (Avena sativa L.). Increased avenanthramide concentrations were found when intact raw groats were steeped. The increase was time‐ and temperaturedependent and maximal after 10 hr of steeping at 20°C. Continuous germination in air, after steeping, only contributed to a further increase in avenanthramides when steeping times were shorter than 10 hr. Concentrations of avenanthramides and HHT activity were positively correlated during steeping of intact groats at 8 and 20°C. The increase in avenanthramides was suggested to be due to de novo synthesis and a whole grain structure seemed to be required as no increase was found when groats were milled before steeping. Avenanthramide levels also increased when heat‐treated samples, lacking HHT activity, were steeped. This increase may be due to release of bound forms, possibly formed during the preceding heat treatment.
Long‐Term Storage Effect in Frozen Dough by Spectroscopy and Microscopy
Authors: Esselink Eddy F. J. , van Aalst Henrie , Maliepaard Manuelle , van Duynhoven John P. M.
Published: June 2007

Storage of dough at low temperatures (‐20°C) has a considerable effect on the final quality of baked bread; this is most obviously reflected in lowered specific volumes. In this study, a suite of structural characterization techniques is applied to examine the underlying mechanism of storage damage at the molecular, microstructural, and macroscopic level. By using infrared spectroscopy, the dehydration of the gluten component could be established at the molecular level, and its kinetics could be monitored in time. Time‐domain nuclear magnetic resonance (NMR) showed increased water mobility, which could be attributed to a release of water from the gluten matrix. At the microstructural level, the growth of ice crystals could be monitored by means of cryogenic scanning electron microscopy (cryo‐SEM). These ice crystals are preferably formed in gas cells with kinetics that are slower than those during infrared spectroscopy but similar to those in time‐domain NMR. At the macroscopic level, ice crystals are not evenly distributed over the molded dough, nor are the gas cells homogeneously distributed over the dough. This has implications for the macroscopic water distribution during frozen storage, which could be substantiated by magnetic resonance imaging (MRI) measurements.
Impact of Industrial Dough Processing on Structure: A Rheology, Nuclear Magnetic Resonance, and Electron Microscopy Study
Authors: Esselink Eddy , van Aalst Henrie , Maliepaard Manuelle , Henderson Thijs M. H. , Hoekstra Niko L. L. , van Duynhoven John
Published: June 2007

Dough processing is an important factor determining the quality of bread. The most important mechanical steps in industrial dough processing are kneading, extrusion, and molding. In all of these processing steps, considerable changes in the structure and properties of the dough can occur. On a laboratory‐scale level, these (structural) effects are well characterized but, so far, no systematic study has been performed at the level of a large‐scale industrial dough processing line. The molecular and microstructural changes that can take place during industrial dough processing were studied with the help of nuclear magnetic resonance (NMR), fundamental rheology, and scanning electron microscopy (SEM). After the kneading step, the dough shows a well‐developed gluten network with a homogeneous dispersion of starch particles (at optimum kneading time). After the extrusion step (a sheeting procedure), the structure of the dough becomes coarser and the dough gluten network is oriented and partially disrupted. This is accompanied with an increase in both rheological stress and water mobility. After molding, the network structure is restored and both the rheological stress and the mobility of water decrease. These findings provide a novel microstructurally‐lead approach to make recommendations for optimization of industrial dough processing lines.
Effects of Yeast Freezing in Frozen Dough
Authors: Ribotta Pablo D. , León Alberto E. , Añón María Cristina
Published: June 2007

The effects of freezing and frozen storage of bread dough and compressed yeast on bread quality were studied. Besides, the effects of compressed yeast freezing on cell viability, gas production and release of substances by the yeast cells were examined. Freezing and frozen storage of dough made with fresh yeast had more negative effects on baking quality than the addition of frozen yeast to dough. When the compressed yeast is frozen and stored at ‐18°C, the CO2 production decreased, while the amount of dead cells, the total protein, and the total reducing substances leached from the yeast increased as the length of yeast frozen storage increased. SDS‐PAGE showed that the substances leached from frozen yeast caused an increase in the solubility of some gluten proteins. On the other hand, size‐exclusion chromatography (SEC) pointed out that the relative amount of two protein fractions of low molecular weight leached from frozen yeast increased for longer yeast frozen storage periods. The yeast leachates had an adverse effect on loaf volume.
Determination of β‐Glucan Molecular Weight Using SEC with Calcofluor Detection in Cereal Extracts
Authors: Rimsten Lena , Stenberg Tove , Andersson Roger , Andersson Annica , Åman Per
Published: June 2007

A high‐performance size‐exclusion chromatography system (HPSEC) was set up with detection based on the specific binding of Calcofluor to β‐glucan for determination of amount and molecular weight of β‐glucan in different cereal extracts. To calibrate the HPSEC system, a purified β‐glucan was fractionated into narrow molecular weight ranges and the average molecular weight was determined before analysis on the HPSEC system. The detector response was similar for β‐glucans from oats and barley and appeared to be independent of molecular weight. Four different methods for extraction of β‐glucan from different cereal products were tested: two alkaline, one with hot water and added α‐amylase, and one with water and added xylanase. Inactivation of endogenous β‐glucanase was crucial for the stability of the extracts, even when extracting at high temperature or pH. Yields varied widely between the different extraction methods but average molecular weight and molecular weight distribution were similar. Extraction with sodium hydroxide generally gave a higher yield and molecular weight of β‐glucan in the extracts.
Influence of Oat β‐Glucan Preparations on the Perception of Mouthfeel and on Rheological Properties in Beverage Prototypes
Authors: Lyly Marika , Salmenkallio‐Marttila Marjatta , Suortti Tapani , Autio Karin , Poutanen Kaisa , Lähteenmäki Liisa
Published: June 2007

The aim was to study the effect of concentration and molecular weight of four different β‐glucan preparations on the perceived sensory quality of a beverage prototype. The correlations between sensory and instrumental measures were investigated. Two of the preparations were brantype containing high molecular weight β‐glucan, two were more‐processed low molecular weight β‐glucan preparations. Twelve beverage samples containing 0.25–2% β‐glucan and one reference sample thickened with carboxymethyl cellulose (CMC) were profiled by a sensory panel and analyzed by instrumental measurements (viscosity and molecular weight). Sensory profiles of the beverages varied at the same concentration of β‐glucan, depending on β‐glucan preparation. Beverages made with the bran‐type preparations were more viscous and had higher perceived thickness than beverages made with more‐processed, low molecular weight preparations. Moderate correlations were obtained between perceived thickness and sliminess and instrumental viscosity at all shear rates between 26 and 100/sec (r = 0.63–0.78; P ≤ 0.001). Technologically, more‐processed β‐glucan preparations are easier to add into a beverage in amounts sufficient for achieving a physiologically functional amount of β‐glucan in a product.
Hydroxypropylated Starch: Granule Subpopulation Reactivity
Authors: Stapley Jonathan A. , BeMiller James N.
Published: June 2007

To determine differences in the reactivity of individual starch granules based on size, maize, wheat, and potato starches were hydroxypropylated then fractionated into subpopulations containing the largest and smallest granules under conditions that minimized leaching. Molar substitution values of the fractions within each starch were similar, indicating little if any differences in reactivity of granules of different size when reacted with propylene oxide, a slow‐reacting reagent.
Characteristics of Noodles and Bread Prepared from Double‐Null Partial Waxy Wheat
Authors: Baik B.‐K. , Park C. S. , Paszczynska B. , Konzak C. F.
Published: June 2007

Double‐null partial waxy wheat (Triticum aestivum L.) flours were used for isolation of starch and preparation of white salted noodles and pan bread. Starch characteristics, textural properties of cooked noodles, and staling properties of bread during storage were determined and compared with those of wheat flours with regular amylose content. Starches isolated from double‐null partial waxy wheat flours contained 15.4–18.9% amylose and exhibited higher peak viscosity than starches of single‐null partial waxy and regular wheat flours, which contained 22.7–25.8% amylose. Despite higher protein content, double‐null partial waxy wheat flours, produced softer, more cohesive and less adhesive noodles than soft white wheat flours. With incorporation of partial waxy prime starches, noodles produced from reconstituted soft white wheat flours became softer, less adhesive, and more cohesive, indicating that partial waxy starches of low amylose content are responsible for the improvement of cooked white salted noodle texture. Partial waxy wheat flours with >15.1% protein produced bread of larger loaf volume and softer bread crumb even after storage than did the hard red spring wheat flour of 15.3% protein. Regardless of whether malt was used, bread baked from double‐null partial waxy wheat flours exhibited a slower firming rate during storage than bread baked from HRS wheat flour.
Staling of Bread: Role of Amylose and Amylopectin and Influence of Starch‐Degrading Enzymes
Authors: Hug‐Iten S. , Escher F. , Conde‐Petit B.
Published: June 2007

The present investigation aims at understanding the mechanism of bread firming during staling. Changes in the starch fraction due to the addition of amylases and their influence on the texture of bread crumb were studied during aging and after rebaking of stale bread. Pan bread was prepared by a conventional baking procedure. The influence of three different starch‐degrading enzymes, a conventional α‐amylase, a maltogenic α‐amylase, and a β‐amylase were investigated. The mechanical properties of bread were followed by uniaxial compression measurements. The microstructure was investigated by light microscopy, and starch transformations were assessed by differential scanning calorimetry (DSC) and wide‐angle X‐ray powder diffraction. Firming of bread crumb and crystallization of starch are not necessarily in agreement in systems with added amylases. Reorganization of both starch fractions, amylopectin and amylose, and the increase of starch network rigidity due to increase of polymer order are important during aging. Starch‐degrading enzymes act by decreasing the structural strength of the starch phase; for instance, by preventing the recrystallization of amylopectin or by reducing the connectivity between crystalline starch phases. On the other hand, starch‐degrading enzymes may also promote the formation of a partly crystalline amylose network and, by this, contribute to a kinetic stabilization of the starch network. Based on the results, a model for bread staling is proposed, taking into account the biphasic nature of starch and the changes in both the amylose and amylopectin fraction.