凤型大曲储藏期不同部位理化指标及微生物群落演替规律分析

Analysis of Physicochemical Indexes and Microbial Community Succession of Fengxiang Daqu during Storage Period

为了深入了解凤型大曲储藏期理化指标和微生物菌群结构对大曲质量的影响,对储藏期大曲不同部位理化指标和微生物多样性进行追踪研究。结果表明:大曲储藏期间微生物会缓慢增长,大曲中水分、淀粉、酸度均有所下降;储藏过程中大曲糖化力、发酵力曲皮高于曲心,酯化力曲心高于曲皮,储藏2~3个月大曲糖化力、发酵力、酯化力较高,后期逐渐趋于稳定;储存期大曲曲皮真菌以Thermoascus、Pichia、Rhizopus为主,曲心以Thermoascus、Aspergillus为主,优势菌属占比不同;曲皮曲心中细菌组成种类相似,均以Lactobacillus、Weissella、Streptomyces为主,但相对丰度占比差异较大。整体来看,凤型大曲储存期曲皮、曲心中微生物多样性和丰富度存在明显差异,曲皮微生物多样性较曲心高。

In order to deeply understand the effect of physicochemical indexes and microbial community structure on the quality of Fengxiang Daqu during storage,the physicochemical indexes and microbial diversity of different parts of Fengxiang Daqu during the storage period were tracked.The results showed that during the storage period of Fengxiang Daqu,the microorganisms grew slowly,while the water content,starch content and acidity decreased;the saccharification power and fermentation power of the skin of the Daqu were higher than that of the core,while the esterification power of the core of the Daqu was higher than that of the skin.The saccharification power,fermentation power and esterification power of the Daqu were relatively high after 2-3 months storage,and gradually stabilized in the later period.The dominant fungi of the skin of the Daqu were Thermoascus,Pichia and Rhizopus,while the dominant fungi of the core of the Daqu were Thermoascus and Aspergillus.The dominant bacteria of the skin and the core of the Daqu were Lactobacillus,Weissella and Streptomyces,but the proportions of their relative abundance were different.On the whole,there are significant differences in microbial diversity and richness between the skin and the core of Fengxiang Daqu during the storage period,and the microbial diversity of the skin was higher than that of the core of Fengxiang Daqu.