Fermentation by lactic acid bacteria (LAB) is an innovative method to improve the gel properties of surimi by induction of non-thermal gel. However, the improvement of gel and inhibition of spoilage microorganisms are limited by the usage of single starter. In this study, the changes in the non-thermal gel properties and microbial community were studied after co-fermentation with Lactiplantibacillus plantarum and Pediococcus acidilactici at low and high concentrations, followed by the clarification of gel change mechanisms. The texture properties, gel strength, and whiteness of tilapia surimi were markedly improved after co-fermentation with starters, while the pH value obviously decreased. The total plate count significantly increased during fermentation in all groups, but remained lower in the co-fermentation groups at 12 and 24 h compared to the natural fermentation group. During co-fermentation, LAB rapidly became the dominant position, and both the starters could adapt well to the fermentation environment. High concentrations of starters not only shortened the gel time from 24 h to 12 h but also obviously suppressed the spoilage microorganisms. Group-dimension correlation analysis at different fermentation time showed that the decreasing richness and evenness of microbial community by starters mainly resulted from the decrease of Lactococcus , Aeromonas , and Streptococcus . The good synergistic effect of starters during fermentation was responsible for the formation of acid environment and consequently improved the non-thermal gel of surimi, and L. plantarum showed higher influence contribution to the non-thermal gel improvement than P. acidilactici . The suppression of spoilage microorganisms by starters also contributed to the non-thermal gel improvement of tilapia surimi. Co-fermentation with high concentration of L. plantarum and P. acidilactici is expected to be used for production of high-quality tilapia surimi products. • Co-fermentation of starters improved gel properties and whiteness of tilapia surimi. • High starters obviously shortened self-gel time and inhibited spoilage microorganisms. • High acidification induced by starters was responsible for self-gel improvement. • L. plantarum had higher contribution to self-gel improvement than P. acidilactici. • Inhibition of spoilage microorganisms contributed to self-gel improvement of surimi.
Wang et al. (Sun,) studied this question.