Study on Quality Differences of Two High-Temperature Daqu Produced in Beijing and Guizhou Regions

High-temperature Daqu is the main aroma source of sauce-flavor Baijiu, which has an important impact on the style and quality of sauce-flavor Baijiu. Sauce-flavor Baijiu produced in Beijing and Guizhou has local characteristics, but the differences in flavor compounds and their causes are still unclear. Correlation analysis was conducted on the quality differences between the physicochemical indicators, microbial community composition, and volatile flavor compounds of high-temperature Daqu from Beijing and Guizhou regions. The results showed that the starch content, liquefaction power, and esterification power in the high-temperature Daqu samples from Beijing were significantly higher than those from Guizhou. However, high-temperature Daqu samples from Guizhou region had higher acidity and saccharification power (P < 0.001). In addition, the core bacterial communities in high-temperature Daqu samples from Beijing and Guizhou regions were Virgibacillus, Kroppenstedtia, while the core fungal communities were Thermoascus and Thermomyces. There were significant differences in the volatile flavor components of high-temperature Daqu between Beijing and Guizhou regions, with Guizhou sample containing more types of volatile substances (27) than Beijing sample (23). Spearman correlation analysis showed that the bacteria with the highest correlation of flavor compounds in high-temperature Daqu from Beijing and Guizhou were different, which led to different flavors of Baijiu in the two regions. The quality differences of physicochemical indicators, microbial community composition and flavor composition of different high-temperature Daqu in Beijing and Guizhou were compared and analyzed in order to further understand the microbial and functional characteristics of high-temperature Daqu in Beijing and Guizhou, and further clarify the reasons for the differences in flavor of Baijiu in the two regions.