Predictive Models to Describe Behavior of S taphylococcus aureus in Sweet Pumpkin Salad Under Constant and Dynamic Temperature

This study developed predictive models to describe the behavior of S taphylococcus aureus in sweet pumpkin salad. A five‐strain mixture of S . aureus was inoculated in 5‐g portions of sweet pumpkin salad. The samples were stored at 10–30C, and cell counts were enumerated. The growth data were fitted to the B aranyi model to calculate lag‐phase duration (h), maximum specific growth rate ( L og cfu/g/h), lower asymptote ( L og cfu/g) and upper asymptote ( L og cfu/g). The growth parameters were then fitted to secondary models as a function of storage temperature. Dynamic models were also developed for changing temperatures. The model was validated using the observed data, and the root mean square error ( RMSE ) was calculated. S . aureus growth was observed at 15–30C. RMSE values were 0.428–0.847. The results indicate that the developed mathematical models should be useful in describing the behavior of S . aureus as a function of temperature. Practical Application Many S taphylococcus aureus strains can contaminate sweet pumpkin salad. The salad may be stored at constant and nonisothermal temperatures, which may cause different S . aureus behaviors. Therefore, the developed model could be useful in describing and predicting the behavior of S . aureus with respect to temperature and time.