Ohmic heating

Both irradiation and microwave heating employ radiant energies which affect foods when their energy is absorbed whereas ohmic heating raises the temperature of foods by passing an electrical current through the food.

Ohmic heating is one of the newest methods of heating foods. Ohmic heating’s major advantage is that is simultaneously heats solid pieces and liquids in a food with minimal destruction. It has been shown that Ohmic heaters can provide an interesting alternative to heat exchanger for thermal processing applications.

Georg Simon Ohm (1789-1854)

In 1827, German physicist, Georg Ohm published his treatise: Dei galvanische Kette, mathematisch bearbeite where he described what is today known as Ohm’s law.

But recognition of the thermal effects of electricity within a conductor was first elucidated by James Prescott Joule in 1840.

This resulted in a number of patents on the heating of flowable materials in the latter part of the nineteenth century. The ‘electric pasteurization’ process was used for milk treatment in six states in the United States in the 1930s.

In the 1980s, Ohmic heating was introduced by APV, who licensed the technology from the Electricity Council of Great Britain.

During this time the technology has achieved some industrial applications that include pasteurization of liquid eggs and processing of fruit products. Ohmic heating has shown good potential for blanching, evaporation, dehydration, fermentation, extraction, sterilization and pasteurization of food products.
Ohmic heating