Effects of salt concentration on the quality and microbial diversity of spontaneously fermented radish paocai

Ting Mi; Dingkang Wang; Shangjie Yao; Huan Yang; Yulan Che; Chongde Wu

doi:10.1016/j.foodres.2022.111622

Effects of salt concentration on the quality and microbial diversity of spontaneously fermented radish paocai

Food Res Int. 2022 Oct:160:111622. doi: 10.1016/j.foodres.2022.111622. Epub 2022 Jul 8.

Authors

Ting Mi¹, Dingkang Wang¹, Shangjie Yao¹, Huan Yang¹, Yulan Che², Chongde Wu³

Affiliations

¹ College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China.
² Zigong Yanweiyuan Food Co. Ltd, Zigong 643010, China.
³ College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China. Electronic address: cdwu@scu.edu.cn.

PMID: 36076372
DOI: 10.1016/j.foodres.2022.111622

Abstract

Paocai is a traditional Chinese fermented vegetable product popular in Asian countries. As an important additive, salt concentration is closely related to the quality of paocai. The aim of this study was to investigate the effect of salt concentration on the physicochemical characteristics, microbial diversity, and flavor profiles of spontaneously fermented radish, and the cross-correlation between microorganisms and flavor compounds was also revealed. Analysis of the microbial diversity of paocai showed that Firmicutes, Proteobacteria, and Ascomycota were detected as the main phyla with different salt concentrations, Weissella and Lactobacillus were the predominant bacterial genera, and Yarrowia dominated the fungal genera. Based on LEfSe analysis, Lactobacillus, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Microbacterium, Lactococcus, Staphylococcus, and Weissella were regarded as differential genera caused by differences in salinity. Analysis of the flavor compounds showed that 17 free amino acids, 5 isothiocyanates, 3 terpenes, 15 sulphur-containing compounds, 16 esters, 8 organic acids, 9 aldehydes, 8 ketones, 25 alcohols, 7 nitriles, 2 lactones, and 10 hydrocarbons were detected. Then, the correlation between the microbial community and flavor compounds was revealed, and the results indicated that several bacterial genera significantly correlated with flavors, including Lactobacillus, Kosakonia, Weissella, Leuconostoc, and Staphylococcus, while fungi had weak correlations with flavors. In addition, Metacyc pathway analysis was carried out to elucidate the effect of salt content on the metabolic pathways, showing that most flavor-related pathways were up-regulated with the increase in salt content. Results presented in this study may contribute to further understanding the role of salt in the fermentation of paocai and provide effective references for quality control of traditional fermented vegetables.

Keywords: Fermented radish; Flavor compounds; High-throughput sequencing; Microbial community; Paocai; Salt concentration.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria
Fermentation
Lactobacillus / metabolism
Leuconostoc / metabolism
Microbiota*
Raphanus*
Sodium Chloride, Dietary / metabolism
Weissella*

Substances

Sodium Chloride, Dietary