To better manage the quality of Daqu and increase the yield of the original liquor, it is crucial to obtain a deeper understanding of the physicochemical indicators and microbial community succession during the storage period of medium- and high- temperature Daqu.Four samples from various storage times were taken from the Luzhou-flavor koji workshop in Northwest China for this investigation.MiSep high-throughput sequencing was utilized to study the diversity of the microbial community during Daqu storage, based on the assessment of their physicochemical parameters.According to the findings, Daqu’s moisture content ranged from 11% to 12% during storage (0-3 months), and after 90 days, its acidity reached 0.75 mmol/10 g.As compared to before they left the room, there was a 66.7% rise in the koji sample.The diversity and richness of microorganisms in Daqu dropped initially and then increased, the most common species were Thermoactinomyces (55.33%), Saccharopolyspora (21.70%), and Thermomyces (59.33%).With storage time, the relative amounts of Weissella and Lactobacillus were generally increasing.Correlation analysis revealed a positive correlation between Lactobacillus, Saccharopolyspora, Weisella, Aspergillus, and Wickerhamomyces with saccharification power.Additionally, Thermomyces showed a positive correlation with liquefaction power, fermentation power, and esterification power.The structure of the microbial population is seen to be continuously modified, balanced, and even stable during the Daqu storage process.It is also related to physical and chemical indexes, which have a direct impact on the yield and quality of liquor.As a result, storing Daqu at medium and high temperatures is a crucial step in the making of liquor.
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