Research progress on application of aroma-producing microorganisms in Baijiu Daqu

Daqu is a saccharifying and fermenting agent and aromatic agent used in Baijiu brewing, and its quality directly affects the flavor and quality of Baijiu. Daqu has a strong dependence on the production environment and undergoes long-term natural domestication in different environments, a variety and stable microbial community could be formed in Daqu, which provides abundant flavor (precursor) substances for the fermentation of Baijiu fermented grains and consequently affects the quality of Baijiu. Therefore, the selection of functional microorganisms for enhanced Daqu production holds broad application prospects. In this paper, aiming at the microorganisms obtained from Daqu with good characteristics, focusing on bacteria (Bacillus sp., Lactobacillus sp.), yeasts (Saccharomyces sp., Zygosaccharomyces sp., Pichia sp.), molds (Monascus sp.) and other microbial genera, the strengthening strategies of functional microorganisms and their effects on flavor substances were reviewed, and the detection methods of common flavor substances were summarized. On this basis, the research direction of functional microbial strengthening in Daqu fermentation was further prospected, which could provide scientific references for ensuring the quality of Daqu and improving the consistency and flavor of Baijiu.