Effect of bran hydration with enzymes on functional properties of flour-bran blends

Authors: PARK, EUN-YOUNG - Chung-Ang University; FUERST, E. PATRICK - Washington State University; Baik, Byung-Kee

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2018
Publication Date: 11/15/2018
Publication URL: https://handle.nal.usda.gov/10113/6471064
Citation: Park, E., Fuerst, E., Baik, B.V. 2018. Effect of bran hydration with enzymes on functional properties of flour-bran blends. Cereal Chemistry. 96(2):273-282. https://doi.org/10.1002/cche.10119.
DOI: https://doi.org/10.1002/cche.10119

Interpretive Summary: Wheat bran present in whole wheat foods provides consumers with many nutritional advantages and health benefits. The decreased product quality and sensory acceptance of whole wheat foods compared to food products made with refined white wheat flour are obstacles to their wide acceptance by consumers. Bran particles present in whole wheat flour are responsible for the low quality and sensory acceptance of whole wheat food products. To mitigate this adverse influence on product quality, wheat bran was first hydrated and treated with degrading enzymes (including cellulase and xylanase) before blending with wheat flour to prepare whole wheat flour and food products. We found that hydration and enzyme treatment changed the composition and functional properties of bran, and resulted in the improved quality of whole wheat bread prepared from blends of the treated bran and refined white wheat flour. Hydration of bran with cellulase or a combination of cellulase and xylanase increased the soluble sugar content, decreased the soluble and insoluble fiber contents, delayed or inhibited starch gelatinization, and decreased water absorption during bread dough development. The loaf volume of bread prepared from flour-bran blends was improved with hydration of bran with xylanase. The results obtained in this study present a practical and effective option for food manufacturers to improve the quality and sensory acceptance of whole wheat bread; this is expected to increase the consumption of whole wheat bread and impart the associated health benefits to consumers.

Technical Abstract: Background and objectives Hard red wheat bran and hard white wheat bran were pre-hydrated and treated with cellulase, xylanase or cellulase+xylanase to mitigate the adverse effects of bran on the bread-baking quality of whole wheat meals. Findings The hydration of bran with cellulase increased its soluble sugar content, and decreased its soluble and insoluble fiber contents. Bran hydration with cellulase+xylanase was more effective at increasing soluble sugar and lowering insoluble fiber, indicating more extensive degradation of cell wall materials. The compositional changes of bran induced by hydration with cellulase or cellulase+xylanase affected the starch pasting and dough mixing properties of the flour-bran blends, showing delayed/inhibited starch gelatinization and decreased water absorption during dough development. A higher loaf volume was observed in bread containing bran hydrated with a low dose of xylanase or cellulase+xylanase in hard red wheat, and in bread containing bran hydrated with low dose xylanase in hard white wheat. Conclusions The pre-hydration of wheat bran with enzymes effectively improves the baking quality of whole wheat meals prepared from flour-bran blends by inducing changes in the composition of bran and subsequently in the physicochemical properties of starch and gluten. Significance and novelty The pre-hydration of wheat bran with enzymes can be an important approach for enhancing whole wheat bread processing.