Dynamic patterns of high-temperature Daqu attributes in continuous production: Investigating the impact of Muqu attributes, production site, and process heterogeneity

Abstract

Quality consistency of high-temperature Daqu (HTD) is crucial for optimizing the production and sensory attributes of Chinese sauce-flavor Baijiu. It is also essential for tracking microbiota succession, enzymatic activity, and metabolic profiles during continuous HTD production. Using multi-phase detection technologies, including high-throughput sequencing and metabolomic analysis, the effects of Muqu (mature HTD) addition and its attributes on HTD properties over multiple production rounds were examined. The results demonstrated that Muqu significantly influenced the microbial community of HTD, particularly increasing the relative abundance of key functional microorganisms, such as Kroppenstedtia and Thermomyces, thereby improving enzymatic activities which were saccharification, fermentation, and esterification activity etc, and optimizing the metabolic profile of HTD. Furthermore, the study revealed that the combined effects of Muqu attributes, production site, and process heterogeneity significantly influence inter-round variations in HTD properties, highlighting the importance of controlling production parameters to achieve consistent quality. These findings provide novel insights into the role of Muqu in shaping HTD microbial communities and metabolic functionally, offering a scientific foundation for optimizing industrial-scale HTD production and improving quality management strategies.