Investigation of microbial succession and volatile compounds dynamics during the fermentation of traditional cereal vinegar in Xinjiang

Abstract

Cereal vinegar, a traditional acidic condiment in China. The quality of cereal vinegars varies depending on the raw materials used to produce them, fermentation methods and brewing environments. To investigate the microbial community succession and metabolite changes on the whole fermentation process of traditional cereal vinegar in Xinjiang, we analyzed it by high-throughput sequencing, high-performance liquid chromatography and head space solid phase micro-extraction-gas chromatography-mass spectrometry technology. The acetic acid (5733.33 mg/100 g), lactic acid (1265.33 mg/100 g) and succinic acid (520.00 mg/100 g), gallic acid (63.09 μg/g) and vanillic acid (29.05 μg/g) were the dominant organic acids and phenolic compounds in traditional cereal vinegar of Xinjiang, respectively. In later stage of aging, high levels of acetoin, ethyl phenylacetate, phenylethyl alcohol and ethyl lactate endowed the cereal vinegar with rosy, fruity and creamy aroma. The functional fungal genera were Saccharomyces, Fusarium and Kazachstania, and the functional bacterial were Pseudomonas, Lactobacillus, Acetobacter, Rhodococcus and Methylobacterium. Spearman's correlation coefficient showed that bacterial community had a strong correlation with various flavor compounds. The results could provide a theoretical reference for flavor enhancement and process improvement of traditional cereal vinegar in Xinjiang.