Mechanistic insights into how fermentation modulates steamed bread quality: The role of starch multi-scale structure...

A clear understanding of how starch in fermented dough affects steamed bread quality is essential for developing superior products. In this study, the multi-scale structure and gelatinization properties of wheat starch were systematically characterized, and their relationships with bread quality were evaluated. Results indicated that fermentation disrupted the lamellar structure of starch and reduced relative crystallinity (from 27.1% to 24.2%) and short-range ordered degree (from 0.89 to 0.73). The disordering of these aggregation structures may facilitate the interactions and entanglements among starch molecular chains, leading to increased peak and final viscosities, particularly at 35 °C. Consequently, the specific volume of reconstituted steamed bread increased from 1.29 to 2.26 × 10^-3 m³/kg, while hardness decreased from 23.31 to 16.92 N. These findings suggest that fermentation-induced structural transformations of starch could improve the continuity, cross-linking and extensibility of starch-gluten matrix, thereby enhancing bread quality.