Non-Invasive Pulsed Electric Field Food Processing: Proof-of-Principle Experiments

Two essential requirements arise before any proposed and novel non-invasive pulsed electric field (PEF) food processing technique can be implemented in industrially meaningful systems. These are the reliable measurement of the intense fast transient electric fields generated in water close to metallic electrodes and a convincing proof-of-principle demonstration of the non-invasive technique. Recently, both of these milestones have been very successfully achieved in a joint research programme in progress at Loughborough University (UK) and Universite de Pau (France). The paper reports on results from preliminary experiments with a non-invasive proof-of-principle treatment chamber, showing the paramount importance of electro-optic measurements. In addition, very successful proof-of-principle non-invasive processing experiments are discussed, in which only extremely small displacement currents flow inside water samples. The electric field in the samples was monitored using the Kerr effect and a 6 log reduction was obtained in the Escherichia coli initially present. The possible future of the novel technology is briefly commented on.