PULSE ELECTRIC-FIELDS OF HIGH-VOLTAGE TO PRESERVE FOODS - MICROBIOLOGICAL AND ENGINEERING ASPECTS OF THE PROCESS - REVIEW

Pulse electric fields of high voltage is a promising technology to pre serve foods without using heat. Conventional heat treatments inactivat e bacteria and other pathogenic microorganisms but the applied heat si gnificantly affects organoleptic and nutritional characteristics of th e treated foods. Pulsed electric fields, in principle, do not alter th e quality of the foods. The inactivation of spoilage microorganisms is accomplished by exposing foods to intense electric fields during shor t periods of time (in the order of mus). The treatment could take plac e either in static or continuous flow chambers having two parallel ele ctrodes supported by an insulator. The design of the chambers takes in to account physical and engineering aspects necessary to process adequ ately a specific food product. This work presents results gathered by several research groups while exposing microorganisms to pulsed electr ic fields. The microbial inactivation is due to cell membrane damage, and this damage depends on the intensity of the electric field, on the treatment time and on the type of microorganisms.