Difference and correlation analysis of the microbial community structure and the volatile flavor compounds of six traditional cereal-fermented beverages in Xinjiang

Traditional cereal-fermented beverages in Xinjiang are highly popular owing to their rich taste and unique flavor. However, there are limited systematic studies focused on their microbial community structures and characteristic flavors yet. In this study, six representative traditional cereal-fermented beverages (magzimu, galema, kvass, corn boza, rye boza, and barley porridge) from different production areas of Xinjiang were subjected to high-throughput sequencing for investigating the microbial community structure, as well as to gas chromatography coupled with ion mobility spectrometry for analyzing volatile flavor compounds. Firmicutes and Ascomycota were the predominant phyla. Lactobacillus , Limosilactobacillus , Furfurilactobacillus , Clostridium sensu stricto 1 , Weissella , and Lactococcus were the dominant bacteria, while Saccharomyces , Kluyveromyces , and Kazachstania dominated the fungi. At the genus level, 18 primary differential microorganisms were identified, with lactic acid bacteria being the main differential group. Furthermore, 53 types of volatile flavor compounds were identified, and 20 volatiles showed significant differences (VIP > 1), including 7 esters, 4 aldehydes, 4 alcohols, 3 ketones, and 2 other compounds. Significant associations confirmed that the core characteristic volatile flavor compounds were primarily formed by the action of Furfurilactobacillus , Leuconostoc , Saccharomyces , and Kluyveromyces . These findings provided fundamental basis for the industrial application and precise fermentation of the traditional cereal-fermented beverages in Xinjiang. • We studied six typical traditional cereal-fermented beverages from Xinjiang. • Eighteen (12 bacteria and 6 fungi) core differential microbial genera were screened. • A total of 53 types of volatile flavor compounds were detected. • Twenty key characteristic flavor volatiles were identified. • Four key microbes were the major contributors to the characteristic flavor.