Revealing the flavor compositions, microbial diversity, and biological functions of Huangshui from different production workshops

Huangshui (HS) is the main by-product of Baijiu production, which possesses abundant organic matter and microbial resources, rendering it valuable for high-value utilization. This study collected HS samples from three production workshops with distinct environments, aiming to assess the impact of the brewing microenvironment on the quality of HS. The results revealed elevated lactic acid content in HS samples, ranging from 7878.09 to 10531.56 mg/L. Esters, alcohols, and acids were the main flavor compounds, with 32 key volatile compounds identified. Lactobacillus emerged as the predominant bacterial genus in HS, while Cladosporium and Aspergillus dominated the fungi. Redundancy analysis (RDA) indicated that the physicochemical parameters of HS were pivotal factors influencing the microbial community. Spearman correlation analysis exhibited significant positive correlations of Cladosporium and Aspergillus with 13 and 3 flavor compounds, respectively, suggesting they may represent the core functional microbial genus responsible for the characteristic flavor of HS. Moreover, HS demonstrated antioxidant and antibacterial activities, further augmenting post-enzymatic hydrolysis. These findings lay the groundwork for screening functional strains and utilizing flavor compounds in HS, laying a theoretical foundation for the application of HS in the food industry. However, efficient separation strategies for functional microorganisms and bioactive compounds necessitate further exploration. • Esters, alcohols, and acids were the main flavor compounds in HS. • Bacterial communities were the main microbiota in HS. • HS physicochemical parameters could drive the microbial community. • Core functional microbial communities of HS were identified.