Growth and survival of Staphylococcus aureus on beef jerky as a function of temperature

Abstract

AbstractThe objective of this study was to investigate the effect of temperature on the growth and survival of Staphylococcus aureus and the possibility of enterotoxin A (SEA) production on beef jerky with a water activity (Aw) of 0.78. Beef jerky without seasoning was inoculated with S. aureus producing enterotoxin A at a concentration of approximately 3–4 log cfu/g and stored aerobically at a temperature range of 10°C to 35°C. A modified Gompertz and Weibull model was used to obtain growth and survival kinetics, respectively, and SEA was measured using a Ridascreen SET Total Kit. Growth and survival of S. aureus on beef jerky was observed at temperatures above 21°C and below 19°C, respectively. The maximum population density was observed, but no SEA production was observed above 25°C. Despite the low Aw of beef jerky, the growth of S. aureus was observed above 21°C, indicating that additional safeguards should be considered to reduce the risk of S. aureus in beef jerky in the retail market.Practical applications Staphylococcus aureus can survive in beef jerky with low Aw of 0.78 and even grow at temperatures above 21°C, indicating that beef jerky with low Aw may present a public health risk. Thus, distribution temperature must be reevaluated for the safety of beef jerky in the retail market.