Development of Kinetic Models and Their Applications to Describe the Resistance of Listeria monocytogenes in Napa Cabbage Kimchi to Fermentation Conditions

Abstract

This study evaluated the survival of Listeria monocytogenes in kimchi using predictive models. Kimchi inoculated with L. monocytogenes was stored at 4, 15, and 25 degrees C, and the cells were enumerated on PALCAM agar. The Baranyi model was fitted to L. monocytogenes counts to calculate lag phase duration, maximum specific growth rate (mu(max); Log CFU/g/h) and death rate (DR; Log CFU/g/h). A polynomial equation was fitted to the kinetic parameters, followed by development of a dynamic model. While L. monocytogenes showed sparse growth at 4 degrees C, obvious growth was observed at 0.041 (15 degrees C) and 0.185 (25 degrees C) mu(max). After 96 (4 degrees C), 60 (15 degrees C), and 24 (25 degrees C) h, L. monocytogenes cells started to decrease at DRs of 0.023, 0.039, and 0.144, respectively, with an RMSE of 0.370, indicating appropriate performance of the models. These results indicate that L. monocytogenes can survive in kimchi, even when it is fermented sufficiently.