Kinetic analysis and dynamic prediction of growth of vibrio parahaemolyticus in raw white shrimp at refrigerated and abuse temperatures

The objective of this study was to develop kinetic models to predict the growth of Vibrio parahaemolyticus in raw Pacific white shrimp as affected by storage temperature. Shrimp samples inoculated with a 2-strain cocktail of V. parahaemolyticus were stored between 8 and 35 degrees C to observe the growth during storage. The growth curves were analyzed with two primary models (Huang model and No-lag phase model) in combination with a suboptimal Huang square-root model using a one-step kinetic analysis method and the USDA-IPMP Global Fit software to estimate the kinetic parameters that minimized the global error. No growth of V. parahaemolyticus in samples was observed at storage temperatures below 10 degrees C. The minimum growth temperatures were 10.8 and 10.5 degrees C as estimated by the Huang and No-lag phase models, respectively. The maximum V. parahaemolyticus population in shrimp samples reached approximately 8.0 log CFU/g during storage. The estimated kinetic parameters, including the minimum growth temperature and maximum cell concentration, matched well with the experimental observations. The kinetic models were validated with two dynamic temperature profiles. The validation showed that both models were equally suitable for predicting the growth of V. parahaemolyticus in Pacific white shrimp. The standard error of prediction is about 1.0 log CFU/g. The models obtained from this study can be used to predict the dynamic growth of V. parahaemolyticus in Pacific white shrimp during post-harvest refrigerated storage and temperature abuse conditions.