Bran hydration and physical treatments improve the bread-baking quality of whole grain wheat flour

Fine and coarse bran particles of a hard red and a hard white wheat were used to study the influences of bran hydration and physical treatments such as autoclaving and freezing, as well as their combinations, on the dough properties and bread-baking quality of whole grain wheat flour (WWF). For both hard red and hard white wheat, WWF containing bran prehydrated to 60% moisture content exhibited higher dough water absorption and longer dough mixing time, and it produced bread with a larger loaf volume and lower crumb firmness at zero and seven days of storage than the corresponding WWF containing bran without prior hydration. Hard red and hard white WWF containing bran preautoclaved at 121°C for 2 h and hydrated to various moisture levels (20-60%) produced bread with a loaf volume comparable to that produced by the corresponding WWF containing nonautoclaved bran of 60% moisture content, suggesting that autoclaving bran could substitute for bran hydration to improve the bread-baking quality of WWF. The bran prehydrated to 60% moisture with or without prior autoclaving, as well as hydrated and frozen bran, resulted in bread with a larger loaf volume than the bran with as-is moisture content. Hydration, autoclaving, freezing of bran, and their combinations appear to be promising approaches for mitigating the deleterious effects of wheat bran on loaf volume of WWF bread.