Modeling microbial inactivation by pulsed electric field

Abstract

Modeling microbial inactivation by pulsed electric fields (PEF) can be approached at different scrutiny levels. The starting point can be the biophysical effects on an individual cell's membranes and organelles, their manifestation at the cellular level, and in turn on the population's survival curve. This chapter focuses on different kinds of population models. It presents empirical phenomenological dose-response models and a method to translate PEF survival data into equivalent thermal inactivation curve at a chosen lethal reference temperature. It includes a proposal to combine deterministic continuous survival and injury models and demonstrations of how stochastic events at the cellular level are manifested in observed inactivation patterns at the population level. The potential utility of the stochastic and deterministic kinetic models in describing PEF inactivation, especially of individual or a very small number of a pathogen's cells, is evaluated and their theoretical and practical limitations highlighted. Briefly assessed are the potential benefits and limitations of models that attempt to account for various degrees of damage that a PEF treatment might cause to a microbial pathogen's or spoilage organism's cells.