Dynamics of the development of an electrical field across cellular membranes-PEF inactivation of microorganisms

The pulsed electric field (PEF) processing of liquid and pumpable products has attracted significant interest from the pulsed power and bioscience research communities due to the nonthermal mechanisms of inactivation which results in preservation of the original characteristics of the product. Although the PEF process has been studied for several decades, the physical mechanisms of the interaction of pulsed electrical fields with microorganisms is still not understood fully. The present work is a study of the dynamics of the electrical field in the PEF treatment chamber with dielectric barriers and in the microorganism´s membrane. It was found that the field in the membrane reaches a maximal value which could be two orders of magnitude higher than the original electrical field in the chamber and this value was attained in a time comparable to the Maxwell-Wagner relaxation time, τ_MW. Thus, the optimal duration of the field pulse during the PEF treatment should be equal to the time τ_MW.