Whole Wheat Sourdough in Improving Whole Wheat Bread Quality: A Focus on Water-Extractable Arabinoxylans and Gluten Structure

Abstract

Whole wheat bread is healthier than refined wheat bread but less popular due to reduced sensory quality. This study aimed to enhance whole wheat bread quality using whole wheat sourdough and investigated the mechanisms involved, confirming the role of water-extractable arabinoxylans (WEAX) in its interaction with gluten proteins. Whole wheat sourdough fermentation produces xylanase, increasing the WEAX content from 4.47 mg/g to 7.90 mg/g after 9 hours, which enhances both protein secondary structures and dough rheological properties. Additionally, a moderate amount of organic acids helps to unfold the gluten structure. The absence of protease activity in the sourdough indicates a limited impact on the degradation of gluten proteins. Moreover, adding sourdough to whole wheat bread resulted in a 61.47% reduction in bread hardness. These results provide a theoretical basis for understanding the mechanisms of whole wheat sourdough affects bread quality and aim to increase quality of whole wheat bread.

Keywords: Whole wheat bread, Whole wheat sourdough, Water-extractable arabinoxylans, Bread quality