Investigation of heat effects in pulse electric field treatment of cellular materials

Abstract

The paper deals with modeling and analysis of coupled electro-thermal processes during the pulsed electric field treatment of cellular materials for extraction of bioactive compounds. Subject of consideration is evaluation of heat effects: appearance of local thermal spots and high temperature gradients in the treated tissue. The presence of these phenomena is important for the processing: it aids the process of electroporation and thereby is useful for the extraction, but also could cause overheating and deterioration of the product quality. The analysis is provided using the finite element method, applied to the coupled time-dependent electric and transient thermal field problem. The mechanisms of heat transfer are studied by numerical simulations corresponding to the parameters (type and duration of electric pulses) of experimental examination of the processes of extraction of substances from vegetable seeds. Two steps are considered in the modeling: before and after electroporation. The field analysis after electroporation is carried out for correspondingly changed size and properties of the contact area between the cells. The obtained results can be used for adjustment of the process parameters in order to improve the yield of the extracted substances, without risk of overheating and degrading the quality of extracted product.