Conductive plastic film electrodes for Pulsed Electric Field (PEF) treatment : A proof of principle

Nowadays Pulsed Electric Field (PEF) treatment of food needs to be performed prior to packaging, either hygienic or aseptic packaging is necessary. New techniques for PEF treatment after packaging can be considered when plastic conductive (film) electrodes can be integrated within the package, so that the package and the product can be treated as a whole. This paper describes a newly developed treatment chamber, which can be used to test the ability of any arbitrary plastic packaging film to be used as electrodes for PEF treatment. Tests with a flexible commercially available electrically conductive copolymer film showed that reduction of Lactobacillus plantarum by PEF was possible. This heat sealable film obeys the mechanical properties of a polymer; however it has an electrical conductivity of 0.75 S m- 1 and approximately 2.3% of the surface area is electrically conductive. The maximum obtained inactivation was 2.1 log10 with a specific energy of 17 J ml- 1. The microbial experiments gave a consistent outcome compared with finite element simulations and with models from literature. Further research to reach real pasteurisation levels is needed as well as issues concerning utilisation of these film electrodes. Industrial relevance: Stainless steel electrodes, which are widely used as electrode material for Pulsed Electric Field (PEF) treatment systems, have as main disadvantage that they exhibit certain wear. This article showed that polymer composites can be considered as electrode material for newly to be developed PEF treatment concepts. With extensive research on food grade composite films the integration of cheap disposable plastic electrodes in food packages comes within reach. © 2010 Elsevier Ltd. All rights reserved