Recent advances on fermentation of mustard plant (Brassica juncea L.): microbial community, fermentation processing and sensorial quality: a review

Mustard (Brassica juncea L.), rich in vitamins, minerals, and glucosinolates, yields fermented products valued for their distinct flavor and health benefits, particularly across East and Southeast Asia. The fermentation process is primarily driven by a complex microbial community dominated by lactic acid bacteria (LAB) such as Lactobacillus fermentum, Lactobacillus pentosus, and Lactobacillus plantarum. These microbes metabolize substrates to generate organic acids, volatile compounds, and free amino acids, which collectively shape the product's flavor and sensory quality. This review systematically summarizes recent progress in mustard fermentation, focusing on: the composition, succession, and function of microbial communities across different regions and fermentation stages and their influence on fermentation characteristics; the regulatory effects of key processing parameters-including fermentation vessel, temperature, and salt concentration-on microbial ecology, metabolic pathways, and final product quality; the chemical basis of taste attributes such as sourness, umami, bitterness, and pungency alongside the formation and evolution of aroma compounds during fermentation, and their links to microbial metabolism and biochemical pathways like glycolysis and the tricarboxylic acid cycle; and the formation patterns of potential risk factors such as biogenic amines and nitrite during fermentation, along with strategies to control their levels through process optimization and starter culture selection. Finally, future research directions are outlined, emphasizing the integration of omics and synthetic biology technologies to elucidate flavor formation mechanisms, develop stable starter cultures, and establish standardized processes. These advances aim to achieve consistent flavor, improved quality, and safe production of fermented mustard products, supporting the sustainable development of the industry.