ESTIMATION OF THE THERMOCHEMICAL NONISOTHERMAL INACTIVATION BEHAVIOR OF BACILLUS COAGULANS SPORES IN NUTRIENT BROTH WITH OREGANO ESSENTIAL OIL

The aim of this work was to validate the prediction of the nonisothermal thermochemical inactivation of Bacillus coagulans spores in nutrient broth, adjusted to 4 °Brix and pH 4.2, with 400 ppm of oregano essential oil (EO), using the Weibull dynamic model proposed by Peleg. First, the spores were heat treated at four constant temperatures. Afterwards, empirical secondary models were employed to describe the influence of temperature on the primary parameters. Finally, primary and secondary models were used to simulate microorganism inactivation under two nonisothermal temperatures, ranging from 90 to 95C every 1 min; and from 90 to 95C for 5 min at each temperature. Even if a limited experimental data was employed for the nonisothermal analysis, it appears that the proposed model can be used to estimate the nonisothermal inactivation of B. coagulans spores in nutrient broth with 400 ppm of oregano EO.