Daqu, the saccharification, fermentation, and aroma-producing agents for Baijiu brewing, is prepared using a complex process. Aging is important for improving the quality of Daqu, but its impact has rarely been studied. This study investigated changes in the physicochemical properties, flavor compounds, and microbial communities during aging of Daqu with a roasted sesame-like flavor. The physicochemical properties changed continuously during aging to provide a high esterifying activity. Aging removed unpleasant flavor compounds and helped to stabilize the flavor compounds in mature Daqu. A high-throughput sequencing approach was used to analyze the changing composition of the microbial communities during aging. Aging helped to modify the microbial population to produce better Baijiu by eliminating low-abundance microbial communities and optimizing the proportion of predominant microbial communities. Nine genera of prokaryotic microbes formed the core microbiota in Daqu after aging. Regarding eukaryotic microbes, Zygomycota, the predominant community, increased in the first 2 months, then decreased in the third month of aging, while Ascomycota, the subdominant community, showed the opposite behavior. Absidia, Trichocomaceae_norank and Rhizopus were the predominant genera in the mature Daqu. Significant correlations between microbiota and physicochemical properties or flavor compounds were observed, indicating that optimizing microbial communities is essential for aging Daqu. This study provides detailed information on aging during Daqu preparation.

中文翻译：

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时效对烤芝麻样风味大曲品质的影响。

大曲，白酒酿造的糖化，发酵和香气产生剂，是通过复杂的过程制备的。老化对于提高大曲的质量很重要，但对其影响的研究很少。本研究调查了具有烤芝麻样风味的大曲陈化过程中理化特性，风味化合物和微生物群落的变化。理化性质在老化过程中连续变化，以提供高酯化活性。老化可以去除令人不快的风味化合物，并有助于稳定成熟大曲中的风味化合物。高通量测序方法用于分析衰老过程中微生物群落组成的变化。老龄化通过消除低丰度微生物群落并优化主要微生物群落的比例，帮助改良微生物种群以产生更好的白酒。老化后，九种原核微生物形成了大曲的核心微生物群。在真核微生物方面，优势菌丝体在衰老的前两个月有所增加，而在衰老的第三个月则有所下降，而优势菌种子囊菌则表现出相反的行为。在成熟的大曲中，主要的属有非洲夜蛾，毛癣菌和根瘤菌。观察到微生物群与理化性质或风味化合物之间的显着相关性，这表明优化微生物群落对于老化大曲至关重要。这项研究提供了有关大曲制备过程中老化的详细信息。