Combined Effects of Temperature, pH and Water Activity on Predictive Ability of Microbial Kinetic Inactivation Model

It is well known that temperature is the key factor controlling the microbial survival/inactivation. However, the interactive effects of further stressing environmental conditions may influence microbial behaviour. The objective of this work was to include, in the inactivation model, temperature, pH and a_w effects using a black box polynomial model, aiming at accurate prediction. Data of Listeria innocua obtained within the temperature range of 52.5 and 65.0 °C, pH of 4.5, 6.0 and 7.5, and a_w of 0.95 and 0.99 were used for model assessment. The relations of such parameters with temperature, a_w and pH were assumed to be polynomials.