• Korean journal of food and cookery science
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• v.26 no.3
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• pp.335-345
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• 2010

The objective of this study was to model the kinetics of S. aureus survival on high risk foods in school foodservice operations. After inoculating S. aureus ATCC25923 onto the various high risk foods, the effects of competitive microorganism, storage temperatures($25^{\circ}C$, $35^{\circ}C$), and initial contamination levels ($1.0{\times}10^2\;CFU/g$, $1.0{\times}10^5\;CFU/g$) on the growth of S. aureus were investigated. Lag time decreased and specific growth rate increased with a storage temperature ($25^{\circ}C$<$35^{\circ}C$) and with a higher initial inoculation level ($1.0{\times}10^2\;CFU/g$<$1.0{\times}10^5\;CFU/g$). Previously it was shown that S. aureus is a weaker competitor than other organisms, but it proliferates aggressively in a noncompetitive environment. However, in our study, when S. aureus was used to inoculate japchae (glass noodles with sauteed vegetables) and meat ball, the growth of S. aureus was similar and more active with competitive organisms than that without competitive organisms. Regardless of other factors, the initial level of S. aureus was a more significant factor of the growth. High inoculation levels of S. aureus were reached at 6 log CFU/g within 3 hours. An incubation temperature of $35^{\circ}C$ and the animal protein component of menu items also were identified as significant factors influencing the growth of S. aureus. Therefore, the duration of time meals are stored before serving should be considered a critical control point. Food service providers must control time and temperature to insure the safety of cooked foods.