Effect of co-fermentation of Pediococcus pentosaceus LWQ1 sourdough and commercial yeast on the quality and flavor of Chinese steamed bread

Sourdough is a traditional starter for Chinese steamed bread (CSB), contributing to its quality and flavor. However, the microbial complexity of sourdough poses challenges for standardized production. Therefore, isolating dominant strains to develop defined starter cultures has become a key strategy, improving CSB quality, and ensuring flavor consistency. Pediococcus pentosaceus is one of the dominant lactic acid bacteria in sourdough, yet its application in CSB remains limited. In this study, the effects of sourdough co-fermented with commercial yeast on the quality and flavor of CSB were investigated. Compared with CSB prepared with commercial yeast alone, sourdough fermented with P. pentosaceus LWQ1 significantly increased the specific volume and the levels of immobilized and free water, without significant alterations in textural properties. Scanning electron microscopy and confocal laser scanning microscopy revealed that sourdough disrupted the continuity of the gluten network, resulting in increased dough expansion and specific volume. Flavor analysis identified 55 volatile compounds, with 1-nonen-3-one contributing most significantly to the flavor profile. Compared with CSB fermented with Limosilactobacillus reuteri , LWQ1-CSB exhibited a flavor profile more similar to the yeast-only control. This study provides a reference for the application of P. pentosaceus sourdough in CSB production. • LWQ1-CSB produced by co-fermentation exhibited the highest specific volume (SV). • The high SV may be related to gluten degradation and the formation of starch gel. • LWQ1-CSB exhibited flavor and texture profiles similar to the control-CSB. • 1-Nonen-3-one was first identified in CSB with the highest rOAV value.