酱香型白酒冬季堆积发酵过程中酒醅升温机制初探

A preliminary study on temperature rising mechanism of fermented grains during heap fermentation process of sauce-flavor Baijiu in winter

为解析冬季酱香型白酒堆积发酵过程中酒醅升温机制,采用实时温度监测仪、传统可培养方法和高通量测序技术,探究一轮次酒醅堆积发酵过程中酒醅温度与真核微生物群落相关性。结果表明,糖化堆中心位置酒醅率先启动发酵,温度缓慢上升并扩散至表层;表层酒醅达到一定温度后,在较充足的溶氧条件下酵母菌快速生长,温度迅速上升,从(15.7±0.21)℃升至(38.0±7.56)℃。堆积发酵过程中,酒醅酵母菌数量获得大幅增长,以毕赤酵母属(Pichia)与伊萨酵母属(Issatchenkia)为优势菌属,从完全收堆至入窖,相对丰度由7.85%增长至83.82%。相关性分析结果表明,酒醅温度与酵母菌数量呈极显著正相关(P<0.01),与毕赤酵母属(Pichia)呈显著正相关(P<0.05)。该研究结果可为进一步阐明酱香型白酒堆积发酵升温机理提供理论参考。

In order to analyze the temperature rising mechanism of fermented grains during heap fermentation process of sauce-flavor Baijiu in winter,the correlation between the temperature of fermented grains and eukaryotic microbial communities in heap fermentation process of the first round of fermented grains was explored by using real-time temperature monitoring instrument,traditional culturable method and high-throughput sequencing technology.The results showed that the fermented grains in the center of the mash were the first to start fermentation,and the temperature rose slowly and spread to the surface.When the fermented grains reached a certain temperature,the yeast grew rapidly under sufficient dissolved oxygen,and the temperature increased rapidly from(15.7±0.21)℃to(38.0±7.56)℃.During heap fermentation process,the number of yeasts in fermented grains increased substantially,and Pichia and Issatchenkia were the dominant strain.The relative abundance of yeasts in fermented grains increased from 7.85%to 83.82%during the late stage of heap fermentation.Correlation analysis results showed that there was significantly positive correlation between the temperature of fermented grains and the number of yeasts(P<0.01),and there was positive correlation between the temperature of fermented grains and Pichia(P<0.05),which provided a theoretical reference for further elucidating the mechanism of accumulation fermentation of sauce-flavor Baijiu.