Correlation between microbial communities and flavor compounds during the fifth and sixth rounds of sauce-flavor baijiu fermentation
Correlation between microbial communities and flavor compounds during the fifth and sixth rounds of sauce-flavor baijiu fermentation
复制标题
酱香型白酒第五、六轮发酵过程中微生物群落与风味物质的相关性
DOI：
10.1016/j.foodres.2021.110741
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发表时间：
2021-10-25
影响因子：
8.1
通讯作者：
Sun, Baoguo
中科院分区：
文献类型：
--
作者：
Wang, Wenhua;Xu, Youqiang;Sun, Baoguo
酱味白酒是以谷物为原料，经微生物共发酵而成的我国传统发酵白酒的代表。整个酿造过程包括7次蒸馏，酿造出7种基酒。最后的成品是七种基础白酒的混合物。因此底酒对最终成品的质量影响很大。六次蒸馏得到的底酒质量明显差于五次蒸馏。但原因尚不清楚，限制了白酒发酵的质量控制。本研究对第5轮和第6轮发酵谷物的上、中、底层风味物质和微生物群进行了比较。其中，苯乙乙酸、己酸乙酯、十二酸乙酯、丁二酸二乙酯和2-羟基丙烷酸乙酯在第6轮的浓度明显下降。与此同时，在第6轮中发现了一种难闻的甲酚。风味化学物质与微生物群的相关分析表明，第五轮真菌在酯合成中起重要作用。部分细菌和真菌种类与对甲酚合成均呈正相关，首次提出了对甲酚代谢途径。这些结果揭示了第五轮和第六轮发酵谷物的风味差异，最终有助于提高白酒的质量。
Sauce-flavor baijiu is a representative of Chinese traditional fermented baijiu using grains as the raw materials through the co-fermentation of microorganisms. The whole manufacturing process includes 7 times of distillation and generates 7 kinds of base baijius. The final product is a mixture of the 7 kinds of base baijius. Thus the base baijius greatly affect the quality of the final product. The quality of the base baijiu obtained by the sixth distillation is obviously poorer than that of the fifth one. However, the reason is still unclear and limits the quality control of baijiu fermentation. In this study, the flavor substances and microbiota in the up, middle and bottom layers of fermented grains in the fifth and sixth rounds were compared. Some flavor esters showed obviously decreased concentrations in the sixth round, including ethyl benzoneacetic acid, ethyl hexanoic acid, ethyl dodecanoic acid, diethyl butanedioic acid, and ethyl 2-hydroxyl-propanoic acid. Meanwhile, an off-flavor pcresol was detected in the sixth round. Correlation analysis of flavor chemicals and microbiota indicated that fungi in the fifth round played an important role for ester synthesis. Some bacterial and fungal species were both positively correlated with p-cresol synthesis, and the related p-cresol metabolic pathways were proposed for the first time. These results revealed flavor divergences of fermented grains between the fifth and sixth rounds, and will ultimately help to improve baijiu quality.