The role of β‐glucanase in modifying dough characteristics, texture and in vitro starch digestibility of highland barley‐enriched bread

Abstract

SummaryThis study aims to evaluate how β‐glucanase impacts dough characteristics, and the in vitro starch digestibility and quality of breads from mixed wheat and highland barley flour at different wheat/highland barley flour weight ratios (70/30 and 50/50). The results showed that β‐glucanase reduced the dough's viscoelasticity and enhanced its extensibility, softness, α‐helix (2.52%–16.12%), β‐sheet (11.10%–31.66%) and free sulfhydryl content (22.70%–34.49%). This helped to mitigate the negative effects of a high β‐glucan content on the wheat/highland barley dough (P < 0.05). Moreover, β‐glucanase improved the specific volume (44.67%–56.56%) and springiness (5.56%–40.41%) as well as reduced the hardness of wheat/highland barley bread (7.50%–71.32%). Furthermore, as the higher content of slowly digestible starch (20.81%–30.84%) reduced the enzymatic rate (k value), β‐glucanase‐treated wheat/highland barley bread exhibited lower starch digestibility (66.17%–71.16%) than white bread (75.37%). Therefore, this study indicated that β‐glucanase played an offsetting role on highland barley bread while maintaining relatively low starch digestibility.