Effects of salt concentration on the quality of paocai, a fermented vegetable product from China.

Background Paocai is a traditional Chinese fermented vegetable food. As the most important ingredient, salt has crucial effects on the bacterial community and volatile compounds of paocai. In order to reveal the effects of salt on the fermentation of paocai, the bacterial composition and volatile compounds were investigated by using high-throughput sequencing and GC-MS. Results The salt had no significant effects on the bacterial community at the phylum level. Proteobacteria and Bacteroidetes gradually decreased during the fermentation, while Firmicutes gradually increased as the dominant bacteria in the late stage of fermentation. At the genus level, Lactobacillus and Lactococcus gradually increased in relative abundance during the fermentation and became the dominant bacteria in paocai. High salt can contribute to the growth of Lactobacillus became the dominant genus in paocai. The salt concentration affected the profiles of volatile compounds in paocai after fermentation. A total of 42 volatile components were detected by GC-MS, among which phenols, aldehydes and nitriles were the main ones. High salt concentration will increase the content of volatile compounds, mainly aldehydes and alcohols, and improve the flavor of paocai. At the same time, the electronic tongue analysis also showed that high salt concentration had a great contribution to the flavor of paocai. Conclusions These data are helpful to elucidate the effects of salt on the quality of paocai and contribute to improve the quality and reduce the use of salt. This article is protected by copyright. All rights reserved.