Effects of biofortification on microbiota dynamics and flavor metabolism in light-flavor Baijiu fermentation process

Daqu, as an important starter and special raw material for Baijiu fermentation, is one of the main factors affecting Baijiu fermentation. Utilizing Daqu fortified with functional strains had an impact on the metabolic activity of microbial community as well as the flavors of the Baijiu that were generated. This work aimed to reveal the function of aroma-producing yeast strain Wickerhamomyces anomalus YW1604 and YW3503 in light-flavor Baijiu, the microbial community structure was investigated, and the results revealed that Pediococcus, Weissella, Wickerhamomyces, Aspergillus, and Saccharomycopsis were the predominant genera. A total of 41 flavor compounds including esters (15), acids (6), alcohols (7) and other compounds (13) were detected in samples during the different stages of fermentation. Among them, the content of ethyl acetate, ethyl butyrate, ethyl lactate, ethyl palmitate, ethanol, and phenylethyl alcohol increased. The results indicate that the fungal community structure in the experimental groups was altered after the addition of W. anomalus, higher contents of aroma compounds and ethyl acetate were mainly correlated with Pediococcus and Wickerhamomyces. This work may provide an effective microbial regulation strategy for Baijiu fermentation, and also provides basic data for the utilization of functional strains to biofortify the Baijiu fermentation process to achieve quality improvement.