Abstract:

The aim of this study was to establish predictive models for the growth of Pseudomonas fluorescens in sturgeon
and its shelf life. Pseudomonas fluorescens, the special spoilage organism (SSO) of aerobically stored sturgeon, was
inoculated to sterile sturgeon fillets and stored aerobically at 0, 4, 10, 15 or 20 ℃. The models were developed based on
the data of kinetic growth of Pseudomonas fluorescens and sensory evaluation, pH, total volatile base nitrogen (TVBN) at
the end of the shelf life of sturgeon. On the basis of the modified Gompertz equation, square root equations and Arrhenius
equations were used as the secondary models to construct the prediction models of growth and shelf life for Pseudomonas
fluorescens. The results showed that the average logarithmic value of Pseudomonas fluorescens was (7.35 ± 0.05) lg (CFU/g)
at the end of shelf life. Meanwhile, the models were validated under isothermal (8 ℃) and non-isothermal conditions. The
residual errors, accuracy factors (Af), bias factors (Bf) and relative errors of shelf lives from the models based on square root
equations were －0.09–0.10, 1.14 and 1.17, 0.97 and 1.02, and －7.95% and －3.28%, respectively. In contrast, the residual
errors, Af, Bf, and relative errors of shelf lives from the models based on Arrhenius equation were －0.17–0.24, 1.21 and
1.31, 0.94 and 1.08, and 24.87% and 7.54%, respectively. In conclusion, the square root equation models were more effective
for predicting the growth of Pseudomonas fluorescens and the shelf lives of sturgeon stored aerobically at 0–20 ℃.

Key words: sturgeon, Pseudomonas fluorescens, temperature, prediction model, shelf life