To set up suitable kinetic models for the evaluation of heat inactivation rate of Listeria monocytogenes in ground beef.
Ground beef, inoculated with 3 strains of L. monocytogenes, was subjected to heating at 55 degrees C, 57.5 degrees C, 60 degrees C, 63 degrees C, 66 degrees C or 70 degrees C to develop the isothermal kinetic models. The survival curves were fitted with modified Gompertz model after the bacterial counts were decreased from 10(9) CFU/g to 10(3) CFU/g. Natural logarithm of mu (the relative inactivation rate) and M (time constant) were fitted with linear regression model. The kinetic models were validated at 59 degrees C and 64 degreeeC.
We established one first-level model and one secondary-level model to predict the inactivation rate. In addition, we validated the accuracy and deviation of the models to guarantee their feasibility.
The models should be suitable for describing the survival of L. monocytogenes in ground beef at different temperatures, which are helpful for the control of the pathogens.
ACTA MICROBIOLOGICA SINICA 05/2011; 51(5):684-91.