Quality Control Strategies for Pit Mud Based on the Synergistic Effects of Flavor, Microorganisms and Physicochemical Factors.

As the core of the solid-state fermentation system, the quality of pit mud is directly determined by the synergistic effects of volatile flavor compounds, microbial communities, and abiotic physicochemical factors. However, pit mud lacks systematic knowledge, especially concerning the dynamic association mechanism and threshold effect of its three components. This results in blind spots within the pit mud metabolism regulation network, which has become a bottleneck in precise pit mud quality regulation. Focusing on the volatile flavor compounds of pit mud is crucial to exploring their association with the core microbial community and physicochemical factors of pit mud, in order to cultivate high-quality pit mud. Although a large number of studies have revealed the formation mechanism of high-quality pit mud based on the three factors and cultivated artificial pit mud through microbial enhancement or synthetic flora to improve the quality. However, anaerobic fermentation is a complex system, and the complexity and dynamics of microorganisms make it difficult for biofortification and synthetic flora to effectively regulate the quality of pit mud. Therefore, this paper reviews the research progress on flavor compounds, microbial communities and abiotic factors associated with pit mud quality, deepens the understanding of their influence on pit mud quality, and proposes a precise environmental control strategy to alter the composition and content of the microbial community in the pit mud. The key to this scheme lies in constructing a correlation network through multi-omics integration to identify the physical and chemical factors related to the quality of the pit mud. During the fermentation process, intervention measures are taken on environmental parameters, ultimately effectively changing the physical and chemical factors, thereby achieving the assumption of precise control of the quality of the pit mud. This provides necessary references and inspirations for improving the quality of pit mud, cultivating artificial cellar mud, and enhancing the quality of Baijiu.