Ohmic Heating as an Advantageous Technology for the Food Industry

Ohmic heating is defined as a process of heating any substance using an electric current. The basic principle is the use of electrical energy for heat using an electric conductor. In ohmic heating, heat can be generated within the food product. The transfer of the heat via the solid-liquid interface is not required and the energy is dissipated directly into the foods. It can be termed an internal thermal energy generation technology. In this process the heating occurs at a very rapid rate, saving a lot of time. The relative conductivity and the relative volume of the food products are responsible for the ohmic heating. Ohmic heating adds value to the product and increases the final quality via the ultra-high temperature and the short period of a high temperature on suspended materials and carrier fluids. Ohmic heating has many applications, such as blanching of food items, evaporation, dehydration, extraction, sterilization, fermentation, pasteurization and heating of food products. In food, ohmic heating can cause some problems such as rupture of a cell, electroporation of the cell, and gelatinization of the starch. Such problems can be eliminated by doing research on ohmic heating. Studies also found that ohmic heating can help in the inactivation of pathogenic microorganisms present in the food, thus making food safe for consumption. The international use of ohmic heating began with APV Bakers Ltd in the 1980s. It was patented by the Electrical Council Research at Capenhurst in the United Kingdom. Ohmic heating was mostly used for low acid food products during those times. After 1993, ohmic heating was used commercially everywhere after its recognition by the US Food and Drug Administration. This chapter highlights the various applications and impact of ohmic heating on the food industry.