Exploring major variable factors influencing flavor and microbial characteristics of Pixian Doubanjiang

Pixian Doubanjiang (PXDBJ) is a typical Asian condiment with a unique spicy flavor produced by traditional spontaneous solid-state fermentation. In this study, flavor and the microbial community characteristics of PXDBJ were investigated based on polyphasic detection approaches, and further revealed the potential regulations of the variable factors on its characteristics. Specifically, the chili varieties and the ripening periods affected the features of organic acids and amino acids, respectively. PLS-DA plot demonstrated that the volatiles contents varied by the intermediate product Banpei and the ripening periods although the predominant aroma compounds were roughly the same. Those results were verified by Spearman's arithmetic (P < 0.05), and established a chili variety-classification model based on OPLS-DA plot (Q2(cum) = 0.918, P < 0.05). In addition, the relative abundance of Saccharomycetales, Zygosaccharomyces, and Muribaculaceae varied with ripening periods, and further revealed the contributions of those variable factors to the flavor and correlated with the predominant microbes. This comprehensive study on the raw materials and spatiotemporal characteristics is valuable for exploring the fermentation mechanism and controlling the product quality.