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

Specificity of an antibody to a subunit of high-molecular-weight storage protein from wheat seed and its reaction with other cereal storage proteins (prolamins)

An antiserum to subunit 2 from the high-molecular-weight (HMW) subunits of the glutenin fraction of Triticum aestivum cv. Highbury was shown to react with related subunits from other cultivars of wheat. The reaction was measured quantitatively by laser nephelometry in polyethylene glycol phosphate-buffered saline after dissolving the HMW fraction in 0.1 M acetic acid; urea used to dissolve the HMW prolamins inhibited the reaction, in some cases at the low concentration of 0.06 M. A study of the comparative reactions of other cereal prolamins was made. ‘D’ hordein, the homologous HMW protein of barley, showed less reaction, which was more inhibited by urea than the wheat subunits. Some ω-gliadins from the wheat cultivars Chinese Spring and Cheyenne reacted more strongly than the injected fraction and there was less inhibition by urea. A-, β- and γ3 of wheat also reacted with the antiserum while a secalin of rye of Mr 40000 gave a weak reaction. RESP-919