Biofortification-driven process intensification in Qingxiangxing Baijiu fermentation: synergistic enhancement of liquor yield, flavor profile, and microbial community dynamics.

While bran-free fermentation contributes to enhancing the sensory quality of Sichuan Qingxiangxing Baijiu, its process efficiency often falls short of the optimum level, particularly manifested as a low liquor yield. To address this bioprocess limitation, this study implemented a targeted microbial biofortification strategy by introducing specific exogenous strains. This approach significantly improved starch utilization efficiency, increasing the liquor yield from 42 to 55%. Simultaneously, the concentrations of key flavor esters (such as ethyl acetate and ethyl lactate) were markedly elevated, achieving a synergistic optimization of production efficiency and product flavor. System-level analysis revealed that the introduction of exogenous strains served as a key driver in reshaping the succession dynamics of the microbial community. By modulating intraspecific competition and interspecific cooperation, they reconstructed the metabolic network, which was closely associated with the earlier and higher-level formation and accumulation of volatile flavor compounds. This study applies biofortification technology to bran-free Qingxiangxing Baijiu production, offering a novel bioprocess control strategy for the simultaneous enhancement of yield and flavor in traditional solid-state fermentation systems.