Correlation between microbe, physicochemical properties of Jiuqu in different plateau areas and volatile flavor compounds of highland barley alcoholic drink

Abstract

Highland barley alcoholic drink (HBD), as one of the most typical rice wines in Qinghai-Tibet plateau area, is generally brewed by adding Jiuqu to highland barley. However, the flavor and quality of HBD fermented with Jiuqu in various plateau regions are different. This study elucidated the potential correlation between the microbial community, physicochemical properties of five traditional plateau Jiuqu, namely Hongxin1 (HX1), Hongxin2 (HX2), Huairang (HR), Hoarfrost gypsophila (HG) and Tibet Qu (TQ), and volatile flavor compounds of HBD. Based on high-throughput sequencing (HTS) technology and LEfSe analysis, it was found that the bacteria and fungi of the five traditional plateau Jiuqu were quite different. Differential microorganisms were Weissella and Pichia in HX1, Lactococcus and Kazachstania in HR, Acetobacter and Rhizopus in TQ. Besides, HX1 and HX2 had higher esterification power, TQ had the highest fermentation power while HR had the lowest enzymatic properties. Finally, RDA and Pearson correlation analysis showed that esterification power and moisture content had positive effects on Lactobacillus, fermentation power and saccharification power were highly positively correlated with Pantoea and Rhizopus, but negatively correlated with Aspergillus. In flavor analysis, Rhizopus, Acetobacter were found positively correlated with alcohols and acids, which contributed to the formation of volatile flavor compounds, Lactobacillus_sanfranciscensis and Lactobacillus_sakei were positively correlated with phenolic compounds. This study showed that the flavor of HBD was seriously affected by the microbiota in Jiuqu, which could help to develop new fortified starter to improve the quality of HBD.