Dynamic evolution of flavor substances and bacterial communities during fermentation of leaf mustard (Brassica juncea var. multiceps) and their correlation

Bacteria are considered an essential influence factor of flavor compounds during vegetable fermentation. This study explored the dynamic evolution of flavor substances and bacterial communities during the fermentation of leaf mustard and revealed their potential relationship. The 16S rRNA gene sequencing revealed that Acinetobacter and Pseudomonas dominated during the first two days. As the fermentation progressed, the relative abundances of Lactobacillus and Lactococcus increased and they dominated after day 9. Redundancy analysis showed that TTA and nitrite content were the main physicochemical factors influencing the revolution bacterial community. Furthermore, the correlation analysis suggested that Lactobacillus was related to 29 flavor substances, including 3 sugars, 5 organic acids, 7 free amino acids, and 14 volatile compounds. The number of flavor substances correlated to Lactobacillus was the largest. This study revealed the relationship between flavor substances and bacterial communities and revealed key microorganisms for leaf mustard fermented.