bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimized Methods for Incorporating Glutenin Subunits into Wheat Dough for Extension and Baking Studies
Authors: Uthayakumaran S. , Stoddard F. L. , Gras P. W. , Bekes F. 
Published: June 2007

ABSTRACTIn order to study the functional properties of glutenin subunits added to a dough, they must be incorporated into the glutenin polymer. This requires partial reduction to open up the polymer, followed by oxidation to incorporate the added monomer into the polymer. Existing methods for incorporating glutenin subunits were suitable only for studies on mixing properties and needed to be modified for use in studies on extension and baking. A range of concentrations and of reaction times was therefore tested for both the reductant and the oxidant. In addition, mixing time as well as relaxation time before extension were varied. Extension curves and loaf heights were used to evaluate the treatments. Optimum conditions were developed that provided extension curves of normal dimensions but with altered shape. The conditions were reduction with 0.2 mg/mL of dithiothreitol (DTT) solution for 1 min followed by oxidation with 5 mg/mL of KIO3 solution, then mixing the dough to 70% of the peak dough development time. For microbaking, the conditions of 2 mg/mL of DTT for 1 min, 2.5 mg/mL of KIO3 for 5 min, and mixing the dough to peak development time allowed loaf height to be retained. The size distribution of the glutenin polymer was analyzed using size‐exclusion HPLC and field‐flow fractionation methods. This showed that the monomers were incorporated into the polymer and that polymer size was restored to control levels following reduction and oxidation.
Basic Rheology of Bread Dough with Modified Protein Content and Glutenin‐to‐Gliadin Ratios
Authors: Uthayakumaran S. , Newberry M. , Keentok M. , Stoddard F. L. , Bekes F. 
Published: June 2007

ABSTRACTThe uniaxial elongational and shear rheology of doughs varying in either the protein content or glutenin‐to‐gliadin ratio were investigated. Increasing the protein content at constant glutenin‐to‐gliadin ratio increased the strain‐hardening properties of the dough, as shown by increasing elongational rupture viscosity and rupture stress. Glutenin and gliadin had a more complex effect on the elongational properties of the dough. Increased levels of glutenin increased the rupture viscosity but lowered the rupture strain, while elevated gliadin levels lowered the rupture viscosity but increased the rupture strain. These observations provide rheological support for the widely inferred role of gliadin and glutenin in shaping bread dough rheology, namely that gliadin contributes the flow properties, and glutenin contributes the elastic or strength properties. The shear and elongational properties of the doughs were quite different, reflecting the dissimilar natures of these two types of flow. Increasing protein content lowered the maximum shear viscosity, while increasing the glutenin‐to‐gliadin ratio increased maximum shear viscosity. Strong correlations between the results of basic and empirical rheology were found. These basic, or fundamental, rheological measurements confirmed prior empirical studies and supported baking industry experience, highlighting the potential of basic rheology for bread and wheat research.
Comparison of Asian Noodles from Some Hard White and Hard Red Wheat Flours
Authors: Seib P. A. , Liang X. , Guan F. , Liang Y. T. , Yang H. C. 
Published: June 2007

ABSTRACTAsian noodles were prepared by an objective laboratory method that included adding optimum water to the dry ingredients, mixing the ingredients to homogeneous salt distribution, and sheeting of the dough under low shear stress. The lightness (L*) values of alkaline‐ and salt‐noodle doughs made from 65% extraction hard white wheat flours (except KS96HW115 flour at ≈70% extraction) were higher than those from 60% extraction hard red wheat flours (except Karl 92 flour at ≈70% extraction). A hard white spring wheat, ID377s, and a Kansas line of hard white winter wheat, KS96HW115, to be released in 2000, gave the highest L* values for dough sheets stored for 2 and 24 hr at 25°C. Cooking losses were 5–9 percentage points higher for alkaline noodles than salt noodles, but the cooking yields of the two types of Asian noodles were almost the same. Cooked alkaline noodles made from a high‐swelling flour (SP93≈21 g/g) gave higher tensile strength than those made from several low‐swelling flours (SP93 ≈15 g/g) with the same protein contents (≈12.5%). However, the cooked salt noodles gave the same tensile strength.
Effects of Laccase and Ferulic Acid on Wheat Flour Doughs
Authors: Labat E. , Morel M. H. , Rouau X. 
Published: June 2007

ABSTRACTThe effects of a laccase from the fungus Pycnoporus cinnabarinus on the mixing of a wheat flour dough with or without added ferulic acid (FA) were studied. Laccase reduced dough time‐to‐peak and accelerated dough breakdown in comparison with the control. Its effect was enhanced with FA. The water extractability of arabinoxylans (AX) increased during mixing of a dough free of added laccase, especially with exogenous FA. At the same time, the extractability of FA decreased during mixing. Added FA may have competed with endogenous AX feruloyl esters, inhibiting partly oxidative gelation. Laccase decreased AX extractability by chain cross‐linking through oxidative dimerization of feruloyl esters. FA and, moreover, FA plus laccase, increased the oxidation of sulfhydryl (SH) groups. FA and, even more, FA in combination with laccase, increased the rate of protein depolymerization during mixing. FA and the products of FA laccase oxidation participated in a redox reaction involving SH groups. A coupling reaction involving enzymatically generated feruloyl radicals and thiol radicals generated through the mechanical breakdown of inter‐chain disulfide bonds might explain these results.
Effects of Flour Strength, Baking Absorption, and Processing Conditions on the Structure and Mechanical Properties of Bread Crumb
Authors: Zghal M. C. , Scanlon M. G. , Sapirstein H. D. 
Published: June 2007

ABSTRACTThe objective of this study was to determine the effects of flour type, baking absorption, variation in sheeting, and dough proofing time on the density, crumb grain (visual texture), and mechanical properties (physical texture) of bread crumb. All response variables were measured on the same bread crumb specimens. Bread loaves were prepared by a short‐time bread‐making process using four spring wheat flours of varying strength. After crumb density measurement, digital image analysis (DIA) was used to determine crumb grain properties including crumb brightness, cell size, cell wall thickness, and crumb uniformity. Tensile tests were performed on bone‐shaped specimens cut from the same bread slices used for DIA to obtain values for Young's modulus, fracture stress, fracture strain, and fracture energy. Proof time had the most profound influence on the bread with substantial effects on loaf volume, crumb density, crumb brightness, and grain, as well as crumb mechanical properties. Increasing proof time resulted in higher loaf volume, lower crumb density and brightness, coarser crumb with fewer and larger cells with thicker cell walls, and weaker crumb tensile properties. Varying flour type also led to significant differences in most of the measured crumb parameters that appeared to correspond to differences in gluten strength among the flour samples. With increasing flour strength, there was a clear trend to increasing loaf volume, finer and more uniform crumb grain, and stronger and more extensible bread crumb. Increasing baking absorption had virtually no effect on crumb structure but significantly weakened crumb strength and increased fracture strain. In contrast, varying the number of sheeting passes had a minor effect on crumb cellular structure but no effect on mechanical properties. The experimental data were consistent with a cause‐effect relationship between flour strength and the tensile strength of bread crumb arising as a result of stronger flours exhibiting greater resistance to gas cell coalescence, thereby having fewer crumb defects.
Creep‐Recovery of Bread and Correlation to Sensory Measurements of Textural Attributes
Authors: Carson Lin , Sun Xiuzhi S. 
Published: June 2007

ABSTRACTBread crumb firmness has been studied extensively with many instruments. Other texture attributes like springiness, cohesiveness, and adhesiveness can be obtained through sensory analysis or by texture analysis using texture profile analysis. In this study, mechanical analysis (MA) was used to study the creep‐recovery of several commercial breads. A descriptive panel was used to analyze these attributes and the results were correlated to MA measurements. With use of a small probe force in the linear viscoelastic portion (50 mN), bread sensory firmness was correlated quadratically to MA creep deformation (r2 = 0.77) and sensory springiness was correlated quadratically to the combination of MA recovery percentage and its rate (r2 = 0.82). With use of a large probe force in the nonlinear viscoelastic portion (600 mN), bread cohesiveness was correlated linearly to the MA recovery percentage (r2 = 0.98). These results indicate that the creep‐recovery test can be used to determine some texture attributes of bread crumb.
Characterization of Oat Endoproteinases that Hydrolyze Oat Avenins
Authors: Mikola Markku , Brinck Outi , Jones Berne L. 
Published: June 2007

ABSTRACTDuring oat seed germination, the insoluble storage proteins must be solubilized and transported to the embryo for use by the developing plantlet. We showed earlier that pH 6.2 active serine and metalloproteinases were the predominant gelatin‐hydrolyzing enzymes of oats, while the oat globulins were degraded by pH 3.8 active cysteine proteases. The pH of the endosperms of germinating oats is 6.2. We have continued our characterization of the germinated oat proteinases by determining which hydrolyze avenins, the oat storage prolamins. Avenins of resting seeds were purified and hydrolyzed with proteinases that were extracted from oat seeds that were germinated for various periods. The peptides released were analyzed using SDS‐PAGE. The α‐avenins were hydrolyzed at pH 3.8 by cysteine proteinases from four‐day germinated seeds and the β‐avenins were hydrolyzed by similar enzymes from eight‐day germinated seeds. At pH 6.2 or pH 5.0, the avenins were not degraded by any of the germinated oats endoproteinases. It is probable that some kind of pH compartmentalization occurs within germinating oat seed. After four days of germination, either new proteinases form or some preexisting proteinases are activated. The cysteine proteinases are apparently responsible for the majority of the storage protein hydrolysis that occurs during oat germination.
Influence of High Molecular Weight (HMW) and Low Molecular Weight (LMW) Glutenin Subunits Controlled by Glu‐1 and Glu‐3 Loci on Durum Wheat Quality
Authors: Brites C. , Carrillo J. M. 
Published: June 2007

ABSTRACTThe progenies of four intervarietal durum wheat crosses were used to determine the effects of glutenin variants coded at Glu‐1 and Glu‐3 loci on durum wheat quality properties. The F2 lines were analyzed for high molecular weight (HMW) and low molecular weight (LMW) glutenin composition by electrophoresis. Whole grain derived F3 and F4 samples were analyzed for vitreousness, protein, and dry gluten contents, gluten index, SDS sedimentation volume, mixograph, and alveograph properties. Allelic variation at the Glu‐B1 and Glu‐B3 loci affected gluten quality significantly. Comparisons among the Glu‐B3 and Glu‐B1 loci indicated that the LMW glutenin subunits controlled by Glu‐B3 c and j made the largest positive contribution, followed by the alleles a, k, and b. HMW glutenin subunits 14+15 gave larger SDS values and higher mixing development times than subunits 7+8 and 20. The positive effects of the glutenin subunits LMW c and HMW 14+15 were additive. Flour protein content, vitreousness, and mixograph peak height values were positively correlated with each other as well as with Dglut values, whereas the SDS sedimentation highly correlated with mixing development time, alveograph strength, and extensibility but was not correlated with the other parameters. The results of quality analysis, together with the results of the genetic analysis, led to the conclusion that SDS sedimentation, mixograph mixing development time, and peak breakdown are the tests more influenced by allelic variation of prolamin. The uses of the results in durum wheat quality breeding programs are discussed.
Effect of Multiple Substitution of Glutenin and Gliadin Proteins on Flour Quality of Canada Prairie Spring Wheat
Authors: Wesley A. S. , Lukow O. M. , McKenzie R. I. H. , Ames N. , Brown D. 
Published: June 2007

ABSTRACTThe effect of genetic substitution of two to four glutenin and gliadin subunits from a Canada Prairie Spring (CPS) cv. Biggar BSR into Alpha 16, another CPS wheat line, was studied for rheological and baking quality. Results from double substitution showed that the presence of a gliadin component from Biggar BSR (BGGL) and low molecular weight glutenin subunit 45 (LMW 45) contributed to improved dough strength characteristics. Presence of BGGL in combination with high molecular weight glutenin subunit 1 (HMW 1) or 17+18 (HMW 17+18) also showed improved dough strength over control Alpha lines. When three or four protein subunits were substituted, even though improved quality performance was observed, it was associated with the negative effect of lowered flour water absorptions in spite of similar protein contents. The study confirms that LMW glutenins, as well as gliadins, play an important role along with HMW glutenins in wheat flour quality. CPS wheat lines with improved dough strength properties can be selected from the double substitution lines with the combination of BGGL/LMW 45 and BGGL/HMW 1.
Reoxidation Behavior of Wheat and Rye Glutelin Subunits
Authors: Antes Susanne , Wieser Herbert 
Published: June 2007

ABSTRACTThe ability of HMW and LMW subunits of wheat glutelin to form a polymeric gluten network by intermolecular disulfide bonds is responsible for the unique rheological properties and baking quality of wheat dough. Because the mechanism of gluten formation is not fully understood, the reoxidation behavior of HMW and LMW subunits of wheat glutelin and HMW subunits of rye glutelin was studied. The subunits were isolated from wheat flour cv. Rektor (REK) and from rye flour cv. Danko (DAN) with a selective extraction and precipitation method. For reoxidation, different oxidants (KBrO3 and KIO3), protein concentrations (0.5, 1.0, and 2.0%), solvent compositions, pH values (2.0 and 8.0), and reaction times (0–360 min) were compared. The characterization of reoxidized products was achieved by the determination of the thiol content with the Ellman's reagent, and of the Mr distribution by gel‐permeation chromatography. The results demonstrated that both HMW and LMW subunits could be slowly reoxidized with KBrO3 to polymers with Mr up to several millions. Yield and Mr distribution of polymers were dependent both on the protein concentration and on the molar ratio of oxidants to thiol groups. The HMW subunits of wheat glutelin (HMW‐REK) yielded slightly higher quantities of polymeric proteins than did the HMW subunits of rye (HMW‐DAN). Reoxidation with KIO3 proceeded much faster than with KBrO3 and led to lower proportions of polymerized proteins for HMW‐REK and HMW‐DAN. Obviously, more intra‐ and fewer intermolecular disulfide bonds were formed by reoxidation with KIO3 compared with KBrO3. In contrast, LMW‐REK was reoxidized with KIO3 to higher amounts of polymeric aggregates, which indicated that LMW subunits formed intermolecular disulfide bonds with both KIO3 and KBrO3. Independent of the protein type and the oxidant used for reoxidation, more inter‐ and fewer intramolecular disulfide bonds were formed when the protein concentration was increased. Single subunits 5, 7, and 10 were isolated from HMW‐REK by preparative acid‐PAGE and were reoxidized with KBrO3 for 360 min. The Mr distribution indicated that x‐type subunit 5 had a greater tendency to form polymers than x‐type subunit 7. The y‐type subunit 10 was characterized by a lower proportion of polymers after reoxidation than x‐type subunits 5 and 7.
Development of Predictive Models for Optimization of Phytate Degradation in Wheat and Rye During Hydrothermal Processing
Authors: Bergman E.‐L. , Fredlund K. , Reinikainen P. , Sandberg A.‐S. 
Published: June 2007

ABSTRACTWhole kernels of wheat (Triticum aestivum ‘Kosack’), rye (Secale cereale ‘Motto’) and rice (Oryza sativa) were hydrothermally treated to reduce the phytate content. The hydrothermal processes used in this study included alternating wet and dry steeping periods. Two hydrothermal processes were used for wheat and rye with two and three wet and dry steeping steps, respectively. The process using two wet and dry steeping steps (process 1) was optimized for phytate reduction with respect to temperature during the process and lactic acid concentration used in the wet steeping steps. Optimal conditions for phytate breakdown in wheat and rye in process 1 were 55°C during the whole process and 1.3–1.5% lactic acid solution as the soaking agent in the wet steeping periods for wheat and 1.3% for rye. The hydrothermal process with three wet and dry steeping periods for wheat and rye (process 2) showed that the temperature used in the third wet and dry steeps did not significantly influence (P > 0.05) the phytate reduction in wheat and rye during these steps. The maximal phytate reduction was 94.4–95.6% in wheat and 99.0–99.5% in rye during hydrothermal processing. In rice, hydrothermal processing resulted, at best, in a 99.8% phytate reduction.
Effect of Milling Ratio on Sensory Properties of Cooked Rice and on Physicochemical Properties of Milled and Cooked Rice
Authors: Park Jung Kwang , Kim Sang Sook , Kim Kwang Ok 
Published: June 2007

ABSTRACTQuantitative descriptive analysis of cooked rice was performed to investigate the effect of milling ratios (≈8.0–14.0%, based on brown rice) on sensory characteristics of cooked rice, in relation to physicochemical characteristics of milled rice and cooked rice. The proximate composition of uncooked rice decreased with increased milling while whiteness increased. The initial pasting temperature of rice flour decreased with increased milling while peak, breakdown, and setback viscosities increased. The instrumental texture profile of cooked rice revealed that hardness and chewiness decreased with increased milling while adhesiveness increased. A trained panel found that color, intactness of grains, puffed corn flavor, raw rice flavor, wet cardboard flavor, hay‐like flavor, and bitter taste were lower while glossiness, plumpness, and sweet taste were higher with increased milling. Degree of agglomeration, adhesiveness, cohesiveness of mass, inner moisture, and toothpacking of cooked rice increased while hardness and chewiness decreased with increased milling. Sensory analysis of cooked rice was more discriminating than instrumental texture profile analysis in terms of hardness, adhesiveness, and cohesiveness. There were high negative correlations between descriptive attributes of sweet taste, degree of agglomeration, adhesiveness, cohesiveness of mass, and moisture (r = −0.94 to −0.87), protein (r = −0.96 to −0.83), and fat contents (r = −0.91 to −0.85). Instrumental hardness showed high correlation with sensory hardness (r = 0.80).
Milling—A Further Parameter Affecting the Rapid Visco Analyser (RVA) Profile
Authors: Becker A. , Hill S. E. , Mitchell J. R. 
Published: June 2007

ABSTRACTRapid Visco Analyser (RVA) profiles were recorded for raw maize grits and two extruded nonexpanded pellets based on wheat and maize. Large differences were found between the profiles obtained when an impeller mill was used to prepare the samples compared with a disk mill. The differences were related to differences in particle properties of the ground products (particle‐size distribution, particle shape, and protein content). Generally, milling the samples with the impeller mill resulted in greater starch conversion than with a disk mill. For raw maize grits, this was shown by X‐ray diffraction, differential scanning calorimetry (DSC), and alkaline viscosity measurements. Several other laboratory mills were tested and all produced particulates with a sieve range of 125–212 μm that had substantially differing RVA profiles. Cooling the sample during milling did not nullify the milling effects. All the laboratory mills produced <20% of the particulates of the size range required for the RVA analysis. The mill used for sample preparation can exert a significant effect on the RVA for both raw and processed cereal samples, even if measurements are made on a defined sieve fraction.
Location of Sites of Reaction Within Starch Granules
Authors: Huber Kerry C. , BeMiller James N. 
Published: June 2007

ABSTRACTTo observe granular reaction patterns within modified starch granules, starch derivatives were converted to thallium(I) salts and viewed by scanning electron microscopy compositional backscattered electron imaging. Observation of phosphorylated potato and sorghum starches and a hydroxypropyl analog of waxy maize starch revealed that granular patterns of reaction were influenced by both starch and reagent types. In waxy maize and sorghum starches, flow of reagent into the granule matrix occurred from channels (laterally) and cavities (from the inside outward). In potato starch granules, which do not possess channels, reagent diffused inward through exterior granule surfaces. Phosphoryl chloride (highly reactive) reacted to a large extent at granule surfaces, while the propylene oxide analog (less reactive) appeared to diffuse into the granule matrix prior to reacting.
Effect of l‐Cysteine on the Rheological Properties of Wheat Flour
Authors: Lambert Ian A. , Kokini Jozef L. 
Published: June 2007

ABSTRACTExtrudate expansion of cereal‐based products is largely dependent on the molecular interactions and structural transformations that proteins undergo during extrusion processing. Such changes strongly influence the characteristic rheological properties of the melt. It is possible to modify rheological properties of wheat flour during extrusion processing, in particular shear viscosity, with cysteine. The objective of this work was to further develop an understanding of the molecular interactions and structural transformations of wheat flour from dynamic oscillatory rheological measurements. Temperature and frequency sweeps were conducted in the linear viscoelastic range of the material. Changes in the storage modulus (G′), the loss modulus (G″) and the loss tangent (tan δ) of 25% moisture wheat flour disks as a function of cysteine concentration (0–0.75%) were monitored. Molecular weight between cross‐links (Mc) and the number of cross‐links (Nc) per glutenin molecule were determined from frequency sweep data. Increasing cysteine concentration broke cross‐links by decreasing G′ maximum and increasing tan δ values. Molecular weight between cross‐links increased and the number of cross‐links decreased. G′ values from temperature sweeps showed a similar trend. This information leads to a better understanding of the viscoelastic behavior of wheat flour doughs during extrusion cooking and elucidation of protein‐protein reaction mechanisms and other interactions in extruded cereal‐based snack foods.