Effect of autochthonous lactic acid bacteria on fermented Yucha quality.

Three strains of lactic acid bacteria (LAB), including two strains of Lactobacillus plantarum and one strain of Lactococcus lactis isolated from spontaneously fermented Yucha, a traditional Chinese home-made fermented fish product, were evaluated as starter cultures for Yucha production. All three starter cultures could drive Yucha fermentation processes by rapid colonizing and fast acidifying the raw fish materials, and restricting the growth of undesirable bacteria. As a result, the starter-inoculated Yucha products were safer than their spontaneously-fermented counterpart, and fewer biogenic amines were detected in them. During the late stage of Yucha fermentation, the initial L. lactis was gradually replaced by endogenous L. plantarum , indicating that Yucha environmental condition is a favorable niche of L. plantarum. Volatile compounds profiling combined with cluster analysis demonstrated that the competition between the two species significantly shaped the development of aroma and flavor compounds in Yucha. Besides, correlation analysis suggested that 1-methyl-naphthalene could be a potential indicator to evaluate the degree of ripeness in Yucha products. • Three starter cultures could all accelerate Yucha fermentation process. • The inoculated Yucha products were safer than their spontaneous counterparts. • The starter L. lactis was replaced by L. plantarum at the end of fermentation. • The interaction between bacteria greatly shaped volatiles profiles of Yucha. • 1-methyl-naphthalene could be an indicator to predict the maturity of Yucha. [ABSTRACT FROM AUTHOR]