|CAI, LIMING - Washington State University|
|CHOI, INDUCK - Korean Rural Development Administration|
|PARK, CHUL-SOO - Chonbuk National University|
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2015
Publication Date: 1/1/2015
Citation: Cai, L., Choi, I., Park, C., Baik, B.-K. 2015. Bran hydration and physical treatments improve the bread-baking quality of whole grain wheat flour. Cereal Chemistry. 92:557-564.
Interpretive Summary: The inferior product quality and sensory acceptance of whole grain wheat bread as compared to refined flour bread are the major obstacles for its widespread consumption. Bran particles of whole grain flour are rich sources of dietary fiber, minerals, vitamins and phytochemicals, and thus are beneficial to human health; however, they negatively affect dough mixing properties and bread quality as well as sensory acceptance of bread. The manipulation of bran to minimize adverse influences on bread baking without compromising health benefits is necessary for the production of whole grain wheat bread with improved quality and sensory acceptance. Effects of hydrothermal treatments including pre-hydration, autoclaving and freezing of wheat bran on dough mixing properties, loaf volume and texture were determined using bran of different particle sizes of two wheat varieties. Pre-hydration of bran significantly increased the dough water absorption of whole grain wheat flour (WWF) and altered dough mixing time. WWF with bran pre-hydrated to 60% moisture produced bread with a significantly higher loaf volume and softer and moister crumb compared to bread baked with non-hydrated bran. Autoclaving of bran also affected the dough water absorption and mixing properties of WWF, and exhibited positive influences on loaf volume of bread. Freezing of pre-hydrated bran either maintained or improved loaf volume of WWF bread. Bran hydration, autoclaving and freezing treatments and their combinations appear to be effective in improving the dough mixing properties of WWF, reducing the dehydration of dough during fermentation and consequently improving WWF bread loaf volume.
Technical Abstract: 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 pre-hydrated to 60% moisture content exhibited higher dough water absorption and longer dough mixing time, and produced a larger loaf volume of bread and lower crumb firmness at 0 and 7 days of storage than the corresponding WWF containing bran without prior hydration. Hard red and hard white WWF containing bran pre-autoclaved at 121°C for 2 h and hydrated at various moisture levels (20-60%) produced comparable loaf volume of bread to the corresponding WWF containing non-autoclaved bran of 60% moisture content, suggesting that autoclaving of bran could substitute bran hydration for improving the bread-baking quality of WWF. The bran pre-hydrated to 60% moisture with or without prior autoclaving, and hydrated and frozen bran resulted in a larger loaf volume of bread of WWF than the bran of 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.