Solid-state fermentation of corn to make Chinese liquor: Effect of corn variety and dynamic microbial community variation

This study aims to evaluate the impact of different corn varieties (Lancaster Sure Crop-LSC, Hickory King White-HKW, and Yellow Dent Corn-YDC) on baijiu fermentation especially focusing on ethanol yield and flavor compounds) and characteristics of dried distillers grains (DDG); and reveal the relationship between flavor compounds and the microbial community in baijiu fermentation. The results showed that LSC generated the highest ethanol (14.73%, v/v) and least methanol (6.6 g/L) concentrations in zaopei (fermented grains before distillation) among the three studied varieties. The DDG from the LSC variety had higher protein (21.14%) and fat (12.20%) contents (dry weight basis) compared to the other two varieties. The results of High-throughput sequencing indicated that both Bacillus and Weissella were dominant bacteria, while Saccharomyces, Saccharmycopsis, and Rhizopus were predominant fungi in all zaopei. In addition, 17 different flavor compounds were found in zaopei, including esters, alcohols, acids, and phenolics. Based on the Pearson correlation analysis, Bacillus, Pediococcus, Leuconostoc, Enterococcus, Weissella, and Pseudomonas, along with Saccharomyces, Saccharmycopsis, Rhizopus, and Mucor fungi, played significant roles in the formation of flavor compounds. These findings deepen our understanding of the microbial contribution to flavor compounds and will help improve baijiu quality.