Effects of trypsin-hydrolyzed wheat gluten peptide on wheat flour dough

BACKGROUND: Gluten peptide was prepared by trypsin hydrolysis and characterized by high-performance liquid chromatographic analysis. The effects on non-frozen and frozen doughs of trypsin-hydrolyzed gluten peptide (THGP) and its combination with ascorbic acid or KBrO3 were investigated. RESULTS: Molecular analysis of THGP showed a decrease in the high-molecular-weight and an increase in the low-molecular-weight sodium dodecyl sulfate-soluble fractions, compared with those of control wheat gluten. The addition of 8% THGP decreased the mixing time and tolerance of the dough, both with and without ascorbic acid or KBrO3. However, the maximum resistance and extensibility of the rested dough containing 8% THGP, with and without ascorbic acid or KBrO3, were not significantly different from those of the control dough. The addition of 8% THGP significantly increased the loaf volume of bread baked from non-frozen dough when combined with 60 ppm ascorbic acid or 30 ppm KBrO3, but it had a significant effect both with and without ascorbic acid or KBrO3 on frozen-dough bread. A large difference in volume was observed between breads made with and without THGP at the oven-spring, rather than at proofing. CONCLUSION: The addition of 8% THGP increased the loaf volume of bread made from freeze-damaged dough and this effect increased when THGP was combined with 60 ppm ascorbic acid. (c) 2008 Society of Chemical Industry