Effect of Mixed Strains on Microbial Community and Flavor Metabolites in Fermentation Process of Chi-Flavor Baijiu

The distinct flavor of chi-flavor baijiu (CFB) has garnered significant attention in China. After the optimization of fermentation conditions, <i>Pichia anomala</i> and <i>Lactobacillus plantarum</i> were introduced into the fermentation process to enhance the flavor. Samples inoculated with these mixed strains (SY) exhibited higher levels of alcohol (from 33.04 to 178.55 mg/L) and esters (from 49.51 to 130.20 mg/L) compared to the control group (KB). In SY, <i>P. anomala</i> and <i>L. plantarum</i> were the predominant microorganisms, while <i>Pediococcus</i> and <i>Saccharomyces</i> were more prevalent in KB. Moreover, 68 volatile flavor compounds were detected in SY, as opposed to 64 in KB. Notably, <i>Pichia</i> showed a positive correlation with key flavor compounds. The synergistic fermentation with exogenous strains led to a 52.38% increase in phenethyl alcohol and a 4.91% increase in ethyl lactate. Additionally, the levels of other flavor compounds, like ethyl acetate, γ-nonanolactone, and (E)-2-octenal, also increased. The results demonstrated that the addition of <i>P. anomala</i> and <i>L. plantarum</i> to the fermentation process of CFB significantly increased the contents of flavor compounds. This research reveals valuable insights into flavor enhancement and the microbial community dynamics in CFB production.