Characterization of variations and correlations between flavor metabolites and microbial communities of industrial paocai brine during fermentation

Paocai brine is the primary source of paocai flavor and microorganisms, while information on industrial paocai brine is unclear. To this end, the variations and correlations of physiochemical characteristics, flavor compounds, and microbial communities during the fermentation of industrial paocai brine were comprehensively studied. The results showed that with the fermentation progressed, compounds with off-flavor, anti-nutritional factors, and food safety risks such as oxalic acid, formic acid, and arginine significantly reduced, while compounds with pleasant flavor, anti-corrosion function, and nutrients such as lactic acid and succinic acid increased. After fermentation, 12 aroma-active compounds had odor activity values (OAVs) greater than 1, and the highest were dimethyl trisulfide, 4-ethylguaiacol, 4-ethylphenol, acetic acid, and 2-(methylthio)ethanol. Lactobacillus and Debaryomyces were the dominant microorganisms, but the flavor formation was the result of the joint action of multiple microorganisms. Practical applications There are few comprehensive studies on the flavor profile and microbe of industrial paocai, so flavor improvement, and standardized production have been difficult problems in the industry. This study provides advanced information for quality control and fermentation process improvement of industrial paocai.