Data analysis of the inactivation of foodborne microorganisms under high hydrostatic pressure to establish global kinetic parameters and influencing factors.

Abstract

The inactivation rate of foodborne microorganisms under high hydrostatic pressure (HHP) is influenced by factors such as substrate, species, strain, temperature, pH, and stage of growth of the cell. In this study, 445 D(P)-values from previously published data were analyzed, including those from bacterial spores, vegetative cells, and yeasts. Three secondary linear inactivation models with pressure and/or temperature as process parameters were tested to estimate global log D(P)-, z(P)-, and z(T)-values, and the influence of these parameters and additional factors was assessed. The results show that significant differences in microbial resistance are mainly the result of temperature, highlighting the need for its inclusion as a process parameter. Perhaps due to the large number of data and very distinct factors, the remaining factors showed no significant differences in microbial resistance, except in the case of Clostridium spp. in soy milk, which showed decreased resistance in this substrate compared with its behavior in other products. These results serve to establish priorities among factors influencing HHP inactivation and to estimate global kinetic parameters as a basis for setting target levels of inactivation. Moreover, they can be used as a benchmark for comparison of microbial HHP inactivation data gathered in future studies.