The correlation between the succession of microflora and volatile flavor compounds in kefir vegetable juice fermentation

Abstract

The dynamic evolution of volatile flavor compounds and microbial community structure during the entire fermentation process was analyzed using high throughput sequencing and GC-MS. The results showed that a total of 42 volatile flavor compounds including alcohols, esters and alkenes were detected throughout the fermentation process. High-throughput sequencing showed that the number of microorganisms in the sample peaked at 24 h of fermentation. Proteobacteria was the most abundant microbiota throughout the fermentation period, underscoring its relative stability during the fermentation process. Correlation analysis showed that Rheinheimera had the highest correlation with alkenes and other volatile flavor compounds. There was a significant correlation between Enterobacteriaceae, Ewingella and ester volatile flavor compounds. There was a significant correlation between Enterobacter, Stenotrophomonas, Sphingomonas and Rheinheimera and alkenes and other volatile flavor compounds. There was also a significant correlation between Prevotella and acid-volatile flavor compounds. In summary, this study provides new insights into the formation of flavor substances and the dynamic changes of microflora during the production of kefir-fermented vegetable juice. At the same time, it also provides a reference for improving the economic added value of agricultural products.Industry relevance: For consumers, water kefir (WK) has become an increasingly attractive natural beverage. In this paper, we elucidated the dynamic properties of WK fermentation by GC-MS combined with gene sequencing. The internal relationship between the composition of the microbiota and the formation of flavor substances in WK fermentation was revealed. These findings represent an important milestone in the understanding of WK microbiology and pave the way for the development of starters with clear flavor substances.