Application of Predictive Microbiology in Monitoring S. aureus Growth in Raw Chicken Meat

Abstract

The frequent outbreaks of foodborne illness owing to Staphylococcus aureus require to deepen into the pathogen's response to different food environments and conditions. This study was conducted to quantify the growth behavior of S. aureus in Tryptone Soya Broth (TSB) using turbidity and plate count methods as well as monitoring and modelling its potential growth in chicken breast and thigh meats at room temperature (25 °C) and refrigeration temperature (4 °C). The calibration curve showed a linear relationship between the turbidity measurement and bacterial cell count in TSB. Moreover, the coefficient of determination index (R 2 ) was 0.8789 which indicates that the linear function was acceptable for reflecting the relationship between them. The growth kinetics of S. aureus obtained from Baranyi model indicated that the maximum growth rate was non-significantly different between turbidity and plate count methods and the primary models fit well (R 2 ; 0.83 vs 0.93) in the two methods, respectively that indicating a good model fitting to our experimental data. The potential growth of S. aureus in raw chicken breast and thigh meats at room and refrigeration temperatures showed that regardless of meats type, S. aureus counts were significantly higher at room temperature than their counts at the refrigeration temperature. In conclusion, predictive food microbiology could be a valuable tool for understanding the growth behavior of S. aureus in artificially inoculated TSB broth and chicken meat.