Changes in flavor profiles and microbial community diversity throughout rice wine fermentation with Rhizopus oryzae...

This study investigates the effects of Rhizopus oryzae of different origins (liquor yeast, tobacco, and apple) on the flavor compounds and microbial community diversity during rice wine fermentation. Integrated approach analysis at 0, 3, 5, and 10 days revealed that strain origin led to distinct microbial succession patterns. At day 10, group J (liquor-derived) was dominated by Hanseniaspora and showed the highest levels of total, sweet, and umami amino acids-increases of 1.67-, 1.49-, and 3.80-fold over group P. Conversely, group Y exhibited significantly higher levels of bitter amino acids than the other two groups did. Flavor analysis indicated that groups J and P had higher ester contents than group Y did, in which context group J exhibited an ethyl butanoate concentration of 8.761 μg/mL. Correlation analysis revealed strong associations (|r| > 0.8, P < 0.05) among the abundances of key microorganisms such as Rhizopus, Bacillus, and Hanseniaspora and the formation of various amino acids and flavor compounds (e.g., 2-octanone and ethyl acetate). These findings provide a foundation for targeted flavor profiling and strain selection in rice wine production.