An innovative and non-invasive technology for PEF food processing

The use of pulsed electric fields (PEFs) is a mature technology used in the industrial processing of food, for example, fruit juice. It is however restricted to liquid (pumpable) food and involves metal electrodes in direct contact with the foodstuff - i.e. it is at present an inherently `invasive´ technology. Recently, Loughborough University has undertaken an experimental programme aimed at demonstrating a new and ´non-invasive´ technology that uses an antenna coupled to a fast high-voltage pulse generator to produce an intense pulsed electric field. The machine that has been built and undergone preliminary testing uses a Tesla-transformer-based pulse forming line generator coupled to a Valentine antenna to produce very intense electric fields in water. The technology developed offers considerable scope for use with any type of food, including solid foods such as meat. Apart from the much greater volume available for processing, and other more or less obvious advantages, the new technique is also highly energy efficient as, unlike the existing invasive approach, it does not drive a current through the food being processed. The paper presents the experimental equipment and explains the type of sensors that need to be developed for measurement of the electric field produced. Some of the major implications the technique may offer for the future of PEF food processing are introduced.