Infuence of the year and HMW glutenin subunits on end-use quality predictors if bread wheat waxy lines

The effects of environment and the high molecular weight glutenins on some quality properties (sedimentation volume, % protein content, and starch pasting viscosity) of bread wheat mutant waxy lines were evaluated. Thirty-eight 100% amylose-free F 2 derived F 6 and F 7 lines were used. The results indicated that the environment did not influence sedimentation volume, mixograph parameters and starch viscosity parameters of waxy flour. Variation in the % protein content was determined mainly by the environment. The sedimentation volume and the mixograph peak development time were influenced by the variation at over expression of Bx7 and the mixograph peak development time was influenced by the Glu-D1 locus. One starch viscosity parameter, time to peak viscosity, was influenced by variation at the Glu-A1 locus. This parameter is significantly lower in the waxy lines than the parent line, which shows the influence of the waxy loci. No significant correlation was observed for sedimentation volume, mixograph parameters, protein content and viscosity parameters of waxy line

Effect of Deamidation and Succinylation on Some Physicochemical and Baking Properties of Gluten

Vital wheat gluten was modified by deamidation and succinylation. Deamidation caused a progressive degradation of gliadin with concomitant increase in low molecular weight components, but glutenin was not affected. Deamidation also markedly increased the net negative charge and surface hydrophobicity of gluten, while the bread loaf volume and dough extensibility were decreased. The most significant change in physiochemical properties of gluten caused by succinylation was an increase in net negative charge. Succinylation led to a pronounced decrease in dough extensibility but no significant changes in specific loaf volume. The data indicated the importance of hydrogen bonding offered by the amide groups of gluten in the breadmaking process. Changes in molecular weight distribution and hydrophobic interaction may also affect the baking performance of gluten. Ionic interaction may be involved in dough development but is less critical in controlling the overall baking performance of gluten.link_to_subscribed_fulltex