Abstract
This study explored the impact of green tea addition on bacterial communities in Moutai-flavored Daqu fermentation using high-throughput sequencing, alongside physicochemical and flavor analysis. Significant differences in microbial succession were observed over the 40-day fermentation period among Daqu types with varying tea proportions, resulting in distinct bacterial communities. Sixteen dominant genera, including Bacillus, Kosakonia, and Weissella, were identified, with their relative abundances and succession patterns varying by Daqu type. For example, Kosakonia was more abundant in the original Daqu (25.9%) compared to tea-added Daqu (5.6%-8.7%) (p < 0.05). Acidity, influenced primarily by Sphingomonas (R (2) = 7.5%-20.1%), was a key factor. In 30% tea-added Daqu, dominant bacterial shifts were regulated by multiple physicochemical factors. Acid- and heat-producing bacteria responded to acidity and temperature changes, enhancing fermentation. Higher tea proportions increased the richness of flavor compounds, with 30% tea-added Daqu showing the highest richness and improved flavor profile. This study demonstrates that the appropriate addition of green tea optimizes bacterial distribution, regulating acidity and temperature, thus improving Daqu fermentation quality. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-025-06211-4.