Journal of Pure and Applied MicrobiologyVol. 8 No. Special Edition Nov. 2014

Mathematical Models to Describe the Kinetic Behavior of Staphylococcus aureus in Potato and Sweet Potato Salad at Constant and Dynamic Temperatures

Ahreum Park, Heeyoung Lee, Soomin Lee And Yohan Yoon*

Department of Food and Nutrition, Sookmyung Women’s University, Seoul 140-742, Korea.

Received on 24 May 2014 and accepted on 09 July 2014

 

ABSTRACT

In this study, we developed mathematical models to describe the kinetic behavior of Staphylococcus aureus. S. aureus was inoculated into potato and sweet potato salads, which were then stored at 10–30°C. The Baranyi model was fitted to the S. aureus growth data to calculate the lag phase duration, maximum growth rate, and upper and lower asymptotes. The square root model and polynomial equation were then used to evaluate the effects of storage temperature on S. aureus growth parameters. Subsequently, dynamic models were developed under dynamic temperatures. To evaluate the performance of the model, relative error (RE) were calculated. Bacterial growth was observed at both constant and dynamic temperatures, and the R2 of the primary and secondary models were 0.959–0.995 and 0.789–0.976, respectively. In addition, the developed models were determined to be appropriate with -0.0108 – 0.0053 of RE. These results suggest that the model is useful for describing the kinetic behavior of S. aureus in potato and sweet potato salads under constant and dynamic temperatures.

Keywords : Staphylococcus aureus, ready-to-eat salad, predictive model, dynamic model.