EFFECT OF MECHANICAL DOUGH DEVELOPMENT ON THE EXTRACTABILITY OF WHEATSTORAGE PROTEINS FROM BREAD DOUGH

Six wheat cultivars covering a range of quality parameters were mixed to various proportions of their optimum work input using mechanical do ugh development (MDD) mixers. Mixing and baking characteristics were d etermined and each dough was subsampled. The proteins were extracted f or analysis by reversed-phase HPLC. Considerable protein mobilization appeared to occur during the MDD process, but the changes appeared to be cultivar-specific and did not indicate how mixing or baking behavio r could be predicted. Protein content in extracted fractions was lowes t for the weakest, poorest quality wheat but failed to consistently ra nk the stronger samples. Acetic acid insoluble protein level decreased with mixing as did extractable high molecular weight glutenin subunit s. Gliadin protein level initially decreased with mixing before rising sharply with overmixing, while low molecular weight glutenin subunits displayed the reverse pattern. The rate of change of the extractabili ty of the protein fractions with work input was greatest for the weake st samples and least for the stronger samples. However, when the prote in quantity in the extractable fractions was plotted against relative work input, the rate of change of protein extractability did not appea r to vary significantly between cultivars of different strengths.