Metagenomics reveals the formation mechanism of flavor metabolites during the spontaneous fermentation of potherb mustard (Brassica juncea var. multiceps). (October 2021)

• Record Type: Journal Article
• Authors: Liu, Daqun; Zhang, Chengcheng; Zhang, Jianming; Xin, Xiaoting; Liao, Xiaojun
• Is Part Of: Food research international. Volume 148(2021)
• Publication Date: 2021-10
• Subjects: Fermented potherb mustard -- Flavor metabolites -- Halophilic bacteria -- Lactic acid bacteria -- Metabolic functions; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2021.110622
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Flavor metabolites vary over the potherb mustard fermentation process. Halophilic/lactic-acid bacteria were dominant after potherb mustard fermentation. Halophilic/lactic-acid bacteria correlate with flavor metabolites of fermented potherb mustard. Halophilic/lactic-acid bacteria may contribute to produce flavor metabolites of fermented potherb mustard. Abstract: Fermented vegetable flavors are closely associated with microbial metabolism. Here, shifts in flavor metabolites and their correlations to the structure and function of fermentative microbial communities were explored during the spontaneous fermentation process of potherb mustard ( Brassica juncea var. multiceps ), a traditionally fermented vegetable from China. Halophilic bacteria (HAB, i.e., Halomonas, Salinivibrio, and Vibrio ) and lactic acid bacteria (LAB, i.e., Lactobacillus -related genera and Weissella ) became highly abundant after potherb mustard fermentation. Further, HAB and LAB abundances exhibited significant, positive correlations with metabolites important in fermented potherb mustard flavoring (e.g., organic acids, amino acids, alcohols, aldehydes, and nitriles). Metagenomic analysis indicated that Halomonas, Salinivibrio, Weissella, and Lactobacillus -related genera were likely actively engaged in pyruvate metabolism (ko00620) and citrate cycle (TCA cycle, ko00020), leading to higher lactic and acetic acid concentrations, along with lower pH, which would affect levels of volatile isothiocyanates and nitriles that contribute to flavoring of fermented potherb mustard. Further, HAB and LAB were the primary populations inferred to be responsible for amino acid and fatty acid metabolism in addition to the biosynthesis of numerous volatile flavor compounds. This study highlights the predominance and importance of LAB and HAB during spontaneous fermentation of potherb mustard and provides new insights into their roles in this process.