ABSTRACT

This chapter reviews ohmic heating in relation to mechanisms and kinetics contributing to microbial death. Interest in rapid methods of heating and nonthermal microbial inactivation resulted in revived attention to electrical and electromagnetic treatments in the 1980s. Ohmic or electrical resistance heating, induction heating, microwave heating, radio-frequency heating, pulsed electric field, electric arc discharge, and oscillating magnetic field treatments are some of the technologies investigated for microbial inactivation. Ohmic or electrical resistance heating involves an application of a low-voltage alternating current to a continuously flowing food product. Ohmic heating has potential applications for processing of liquid-particle mixtures, highly viscous, and heat-sensitive food products. Ohmic heating could also produce better quality highly viscous and heat-sensitive food products than conventional heating for the same reason of internal heat generation. B. E. Horrall reported that the temperature required to kill Escherichia coli and Microbacterium tuberculosis using the electropure process was lower compared to conventional heating.