Seasonal variation shapes microbial succession and volatile flavor profiles during the production of strong-flavor Daqu

Food Res Int. 2026 Oct 31;242(Pt 1):119812. doi: 10.1016/j.foodres.2026.119812. Epub 2026 Jun 22.

ABSTRACT

Daqu is a fermentation starter for baijiu, and its quality is influenced by physical, chemical, environmental, and seasonal factors. However, the seasonal differences in the microbial communities and their functions within Daqu remain unclear, despite being closely related to the flavor and quality of baijiu. This study investigated the dynamic changes in physicochemical properties, microbial communities, and volatile flavor during the production of strong-flavor Daqu in summer (SU) and winter (WI). Lactobacillus, Weissella, Leuconostoc, and Bacillus were identified as the dominant bacterial genera, while Pichia, Dipodascus, Trichosporon, and Aspergillus were the dominant fungal genera. Using a random forest algorithm, 17 microbial biomarkers were identified across different seasons. Co-occurrence network analysis revealed that the WI network exhibited greater complexity and stability, and seven keystone taxa were identified. Neutral community model (NCM) and modified stochasticity ratio (MST) were applied to explore the microbial assembly mechanisms. The results indicated that stochastic processes shaped the bacterial communities in both seasons, while deterministic processes played a key role in shaping fungal communities. Additionally, 49 differential flavor compounds were identified. Correlation analysis showed that the dominant genera were closely associated with the variation in volatile flavor compounds. These findings are of significant value for exploring quality control and management strategies in the natural fermentation process of Daqu.

PMID:42629045 | DOI:10.1016/j.foodres.2026.119812