The use of direct resistance heating in the food industry

Abstract Direct resistance heating (DRH) offers the chance to process solid and liquid foods at the same rate, avoiding the delay due to thermal conduction which prevents the use of HTST technologies on paniculate foods. The attempts to exploit the advantages of DRH in food processing over the last century are reviewed. A successful DRH unit requires non-contaminating electrodes which have a good contact with the food material, control of the food heating rate and, if sterilisation is required, an efficient aseptic packaging process. Recent developments in these three areas mean that the advantages of direct resistance heating can now be commercially exploited.