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Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/24/2003 Publication Date: 3/24/2003 Citation: HUANG, L. MATHEMATICAL MODELING OF GROWTH OF CLOSTRIDIUM PERFRINGENS IN COOKED BEEF. JOURNAL OF APPLIED MICROBIOLOGY. 2003. V. 23. P. 91-105. Interpretive Summary: The spore-forming Clostridium perfringens is a major foodborne pathogen in processed meat products such as ham, roast beef, and corned beef, and temperature abuse is the primary cause of C. perfringens-related food poisoning. The objective of this research was to investigate the influence of temperature on the growth of C. perfringens in cooked ground beef and develop mathematical models to describe the bacterial growth. Three growth models were developed and compared. These models may provide accurate estimation of the growth of C. perfringens in processed meat products. If adopted by the industry, these models can help design better cooling procedures. They can also be used by regulatory agencies, retailers, and consumers to estimate and predict the potential bacterial growth during distribution and storage of meat products. Technical Abstract: The objective of this work was to study the growth kinetics of Clostridium perfringens spores in thermally processed ground beef and compare the suitability of the Gompertz, logistic, and Baranyi models used to describe the isothermal bacterial growth. Ground beef samples inoculated with the spores of three strains of C. perfringens were incubated under isothermal conditions between 17-50oC. The isothermal growth data were analyzed by nonlinear regression to fit the growth curves to the Gompertz, logistic, and Baranyi models. Although all three models were capable of depicting the growth of this organism, analytical results indicated that the Gompertz model best described the physiologically progressive growth nature of C. perfringens in cooked beef. The effect of temperature on the growth of C. perfringens was also investigated using a modified Ratkowsky model. The minimum, optimum, and maximum growth temperatures of C. perfringens in cooked beef were 10, 47, and 51oC, respectively. Statistical analysis also revealed a linear relationship between the durations of the lag and exponential phases of growth curves. Such a linear relationship would allow the generation of a complete linear isothermal growth curve containing the lag, exponential, and stationary phases without complicated mathematical manipulation. The results of this study can be applied to the industry to design appropriate cooling schedules and estimate the extent of C. perfringens growth in thermally processed beef under abused temperature conditions. It may contribute to the prevention of foodborne poisoning caused by C. perfringens spores during manufacturing, distribution, storage, and consumption of cooked beef products. |
