Effect of microbial communities on flavor profile of Hakka rice wine throughout production

Hakka rice wine is produced from grains by co-fermentation with abundant microbes in an open fermentation environment. Indigenous microbiota and enzymes convert the nutrients in grains into flavor compounds through enzymatic biochemical reactions and microbial metabolism. High-throughput sequencing technology revealed that non-Saccharomyces yeasts dominated the traditional fermentation process, with genera such as Kodamaea ohmeri, Candida orthopsilosis, and Trichosporon asteroides forming a dynamic community that highly correlated with the evolution of 80 volatile compounds in Hakka rice wine. Among the 104 volatile compounds detected by GC-MS, 22 aroma-active compounds with relative odor activity values (ROAV) > 1 were quantified, 11 of which made significant contributions (P < 0.05) to the overall aroma and were responsible for the sweet, grainy, and herbal aromas of Hakka rice wine.