Abstract: Vacuum-packed tuna and salmon fillets were stored at 0, 4, 8 ℃ and 12 ℃, respectively, and the total viable counts (TVC), lactic acid bacteria counts, and total volatile basic nitrogen (TVBN) were determined during storage in order to establish a predictive model for the shelf-life of each species of fish fillet. A modified Gompertz equation was used to describe the dynamic growth of lactic acid bacteria under fixed temperature. The temperature dependence of μmax and Lag was described by a Belehradek type model. Results showed that the modified Gompertz model could well describe the growth dynamics of the lactic acid bacteria under fixed temperature, and the Belehradek model could also well describe the effect of temperature on the μmax and Lag of lactic acid bacteria with a linear relationship. Meanwhile, the models were validated by the experimental data of lactic acid bacteria growth in vacuum-packed fillet during storage at 6 ℃. It was found that the growth of lactic acid bacteria in both fillets could be fitted well with the models.

Key words: tuna fillet, salmon fillet, lactic acid bacteria, shelf life