Abstract: The survival rates of four Vibrio parahaemolyticus strains inoculated into Trichiurus japonicus samples were measured during 60 days of storage at 4 ℃ and -20 ℃ and their survival curves were plotted respectively. The results showed that the survival cells decline by 6.55～8.22 lgCFU at 4 ℃ during 60-day storage period. And the survival curves showed that in initial 20 days, the mean inactivation speeds are slow, 0.06～0.1 lgCFU/d; In 25～35 days, rapid drop with 0.16～0.2 lgCFU/α occurs; and during the followed period of 25 days, the mean inactivation speeds are 0.11～0.12 lgCFU/d. There were some differences among inactivation speeds of different strains of Vibrio parahaemolyticus, and the drop of Vp06001 is significantly faster than that of the other 3 strains (p<0.05). During storage period at -20 ℃, the survival cells decline rapidly by 0.39 lgCFU/α speed in initial 5 days, until the 60th day slow drop follows by 0.027 lgCFU/d. There were no significant differences among inactiviation speeds of different strains (p>0.05). Linear, Weibull and Log-logistic models were applied to fit survival rates data, and four evaluation parameters such as accurate factor (Af), bias factor (Bf), root mean square error (RMSE) and square correlation coefficient (R2) between predicted and observed values were analyzed. And the results showed Log-logistic model produces better fitness for data than Linear and Weibull model at 4 ℃ storage. However, at -20 ℃, Weibull model is better than other two models for describing inactivation kinetics of four Vibrio parahaemolyticus strains.

Key words: Vibrio parahaemolyticus, low-temperature storage, inactivation kinetics, model