Dynamic Changes in Glutenin Macropolymer during Different Dough Mixing and Resting Processes

The glutenin macropolymer (GMP), which is an important component of the glutenin protein in wheat flour, plays a prominent role in governing dough properties and breadmaking quality. This study investigated the changes in GMP properties during the mixing and resting stages of dough processing. The results show that the GMP content decreases by about 20.20% when the mixing time increases from 3 to 5 min, while increasing the resting time can lead to restoration of some GMP contents. Resting promotes greater formation of large-sized GMP particles, which is likely related to the increased disulfide bond content in the GMP during this process. In contrast, the mechanical force of mixing causes GMP depolymerization and formation of smaller particles. Furthermore, after mixing, the protein secondary structure tends to be disordered, the protein morphology becomes irregular, and the protein subunit ratio changes. Thus, mixing has many of the opposite effects to resting, although resting can (to some extent) restore the properties of the GMP after mixing. However, excessive resting time can lead to negative results, reflected in lower disulfide bond (SS) and GMP contents, and more irregular particle sizes. The presented results suggest that dough mixing induces rearrangement of the dough’s protein structure, and resting somewhat restores the chemical bonds and internal protein structure.

Assessment of high yielding local Pakistani bread wheat genotypes for improved chapati making quality

The experiment was conducted to classify the maximum glutenin protein possessed Pakistani bread wheat genotype for superlative chapati making quality by ten yield-related parameters. The studied germplasm was acquired from NARC, Pakistan, and planted in randomized-complete-block-design with four replicates at the screen house of the Genetics Department. Data were assessed via Duncan’s test, correlation analysis, SDS-PAGE, and cluster analysis. Duncan’s test conceded that Pirsabak-85 had the highest plant height, flag leaf area, biomass, grain yield plantˉ1, harvest index, and protein content. While, the correlation studies showed that plant height, tillers plantˉ1 (r = 0.649), fertile tillers plantˉ1 (r = 0.713),biomass (r = 0.861), spike length (LS), thousand-grain weight and harvest index had a positive higher significant association with grain yield plantˉ1. The SDS-PAGE analysis resolved 30 diverse high and low molecular weight bands, ranging from 200 kDa to 28 kDa glutenin subunits. Among genotypes, Pirsabak-85 showed maximum protein content and 10 Glu-1 scores. The dendrogram analysis revealed that Pirsabak-85 associated with cluster-II, which was a major and most diverged cluster. The Pirsabak-85 can be utilized to enhance bread wheat production and better chapati making quality

Cloning and characterization of high molecular weight glutenin gene from Triticum aestivum cultivar Dacke

<p class="abstract"><strong>Background:</strong> High molecular weight (HMW) glutenin protein plays a crucial role in determining dough viscoelastic properties that determines the quality of wheat flour. The aim of the present study was to isolate, clone and analyze (<em>in silico</em>) the HMW glutenin gene of <em>Triticum aestivum</em> cultivar Dacke.</p><p class="abstract"><strong>Methods:</strong> Primers were designed to amplify a 2445 bp fragment of HMW glutenin gene. Ax type HMW glutenin gene from <em>Triticum aestivum</em> cultivar Dacke was isolated using PCR and it was sequenced by primer walking. </p><p class="abstract"><strong>Results:</strong> Amplified HMW glutenin gene was designated as HMWGAx. Sequence analysis revealed a complete open reading frame encoding 815 amino acid residues with N- and C terminal non-repetitive domain and a central repetitive domain. The calculated molecular weight of the deduced HMW glutenin protein was ~88 kDa and the number of cysteine residues in the HMWGAx was four, in accordance with other x type HMW glutenin proteins. Phylogenetic analysis revealed 100% homology to the previously studied Ax2* type HMW glutenin gene from cultivar Cheyenne. Predicted secondary structure results showed that it was similar to1Ax1 type of common wheat (<em>Triticum aestivum</em>), having superior flour milling quality.</p><p><strong>Conclusions:</strong> Sequence analysis suggests that HMWGAx protein significantly and positively correlates with the properties of elasticity and extensibility of gluten. </p>

ALLELIC COMPOSITION OF HMW-GLUTENIN PROTEIN AND THEIR RELATIONSHIP WITH QUALITY OF WHEAT

High molecular weight glutenin subunits (HMW-GS) proteins deposited inendosperm of wheat seed which have significant impact on bread quality. TheHMW-GS encoded by genes located at the long arm of chromosomes 1A, 1B, 1D.The aim of this work was study allele polymorphysms at Glu-A1, Glu-B1 and Glu-D1 locus and loaf volume, grain protein content, sedimentation volume of eightwheat genotypes (G-3130, G-35183, G-3501, G3512, G-3574, G-3027, G-3075, G-3097) harvested in two years with various weather condition. For each genotypes,flour used for extraction of glutenin which separated by method of electrophoresison SDS gel (11.8%). Electrophoregrams used for determining Glu-1 alleles.Technological quality parameters analyzed by standard laboratory methods. Thethree alleles alleles (a, b, c) at the Glu-A1, three alleles (b, c, d) at the Glu-B1 and 2alleles (a, d) at the Glu-D1 were identified. The highest protein sedimentationvolume had wheat genotype G-3075 in the both years (54.0ml; 58.0ml) while thelowest sedimentation volume had G-3512 (34.0ml; 36.0ml). Grain protein content(GPC) was the highest in G-3075 in both years (14.20%; 15.40%) while the lowestGPC had G-3097 (11.60%) in first and G-3512 (12.60%) in the second year. Loafvolume was the highest in G-3075 in both year (520ml; 540ml) while the lowestwas in G-3512 (400ml) in both years of experiment. The estimated quality traitsvaried depending on genotype and year. The better quality, in average, had thewheat genotypes which carried Glu-D1d allele.