Purpose: This study developed a dynamic model to describe the fates of C. perfringens in processed pig trotter as a function of temperature and storage time.
Methods: A endospore mixture of C. perfringens (NCCP10970, NCCP10846, NCCP10347, NCCP10858, NCCP15911, and NCCP15912) were inoculated in marinated steamed pig trotter at 4 log CFU/g. The inoculated samples were then stored at 10oC (8 days), 15oC (5 days), and 25oC (2 days). C. perfringens cell counts were enumerated on tryptose sulphite cycloserine agar in anaerobic condition during storage. The cell counts data were fitted to the Baranyi model (primary model) to calculate death rate (DR; log CFU/g/h) and shoulder period (SP; h). A polynomial equation (secondary model) was then fitted to DR and SP as a function of storage temperature, and a dynamic model was developed in accordance with primary and secondary models. The model performance was evaluated by root mean square error (RMSE), accuracy (A) factor, and bias (B) factor.
Results: From 10 to 20oC, SPs were rapidly decreased (P<0.05), and DRs were increased (P<0.05). Developed secondary models were appropriate to describe the effect of storage temperature on the kinetic parameters with 0.995 of R2 for SPs and 0.993 of R2 for DRs. In addition, the performances of developed models were appropriate with 0.527 of RMSE, 1.07 of B factor, and 1.08 of A factor. The prediction of developed dynamic model was also appropriate at changing temperatures.
Significance: These results indicate that the developed dynamic models should be useful in describing the kinetic behavior of C. perfringens in marinated steamed pig trotter during storage.