Mechanism of Shaoxing-flavored T3 Jiuqu co-fermentation in enhancing cigar wrappers fermentation quality

To investigate the mechanism by which Shaoxing-flavor T3 Jiuqu affects fermentation quality of cigar wrappers, CX-026 cigar wrappers produced in Enshi, Hubei Province were applied. Using box fermentation combined with GC-MS, continuous flow analysis, HPLC, and metagenomic sequencing, how T3 Jiuqu influences volatile aroma compounds, chemical composition, and microbial community structure were analyzed. The results showed that T3 Jiuqu significantly increased total amount of volatile aroma substances reaching 2910.12 ug/g during the third pile-turning. Among them, carotenoid degradation products (4,7,9-megastigmatrien-3-one and beta-ionol) were increased by 1530.83% and 178.70% respectively compared with natural fermentation group (WF group). T3 Jiuqu optimized sugar-nitrogen metabolism: the total nitrogen content increased continuously, the total sugar retention rate was 15%-20% higher than that of WF group, and malic acid and aspartic acid accumulated significantly. It also significantly altered the microbial community: at the phylum level, the abundance of Proteobacteria increased from 5% (unfermented group, NF group) to 49%, while that of Uroviricota decreased from 87% to 19%; at the genus level, it promoted the colonization of Saccharomyces and Pantoea. The proportion of the dominant genus Staphylococcus was maintained above 88%. Correlation analysis showed that Saccharomyces was positively correlated with leucine, phenylalanine and beta-ionol, while Pantoea was significantly associated with sclareol and aspartic acid. In conclusion, T3 Jiuqu enhances fermentation quality of cigar wrappers by directionally regulating microbial community structure, activating carotenoid degradation and Maillard reaction pathways, and optimizing metabolite composition, providing theoretical support for optimization of industrial fermentation process of cigar wrappers.