Electromagnetic modeling of the breakdown phenomenon in P.E.F. Liquid food treatments

Abstract

Classical liquid foods treatments methods are various forms of thermal processing which trigger unwanted reactions (bad colour, loss of flavour, nutrients and vitamins). Therefore great needs of fresh-like foods induce interests in non-thermal processing methods such as Pulsed Electric Fields (PEF) developed to minimise the above observed degradations. Many empirical experimental results have been obtained: PEF applied to liquid foods should hold some characteristics in order to obtain the inactivation of the unwanted micro-organisms. Some authors affirm that the exposed microorganisms to PEF may result in dielectric breakdown of the cell membrane that can be reversible or not depending on the parameters of the applied PEF. But the modelling of the destruction due to PEF still remained not well known. The aims of the present study are to propose models and solutions that describe quantitatively that phenomenon of microorganism inactivation obtained by PEF. We limit the analysis to the specific case of Saccharomyces-cerevisiae micro organism. The originality of this article consists in combining electromagnetic studies with finite elements method to analyse that mechanism of inactivation. Different models and graphs of values of physical quantities focusing on the effects of the PEF on microbiological cells also constitute some of the results.