Effect of Lactobacillus plantarum and flavourzyme on physicochemical and safety properties of grass carp during fermentation

• Fermentation decreased pH and Aw and increased ANN, TBARS, TVB-N, and BAs in grass carp flesh. • Fermentation with Lactobacillus plantarum and flavourzyme could improve physicochemical properties of fermented grass carp. • Fermentation of Lactobacillus plantarum and flavourzyme could contribute to fermented grass carp with safety properties. The present study aimed to investigate the change in physicochemical and safety properties of grass carp during fermentation with flavourzyme and Lactobacillus plantarum (FLF). The natural fermentation (NF) and fermentation with Lactobacillus plantarum (LF) samples were used as control. The results showed that with increasing fermentation time, the pH and water activity (Aw) in each fermented grass carp sample gradually decreased, while the a-amino nitrogen (ANN), thiobarbituric acid reactive substance (TBARS), total volatile base nitrogen (TVB-N), biogenic amines (BAs), and harmful microbial gradually increased. Besides, compared with NF samples at each fermentation time, significantly lower pH, Aw, TBARS, TVB-N, BAs, and harmful microbial presented in LF and FLF samples. However, FLF samples have a higher AAN content than that of NF and LF samples during fermentation. Overall, the fermentation with Lactobacillus plantarum and flavourzyme could contribute to fermented grass carp products with better physicochemical and safety properties.