Food processing of Ohmic heating

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.

In this method the food is placed between two electrodes serving as an electrical resistor and an alternating electric current is passed through the circuit.

Due to the electrical resistance, heat is generated volumetrically in the form of internal energy throughout the food. The electrical energy is directly converted into the heat causing a temperature rise.

Hence, ohmic heating is sometimes also referred to as Joule heating, electrical resistance heating, direct electrical resistance heating, electro-heating or electro-conductive heating.

Ohmic heating has been practiced since the nineteenth century, when a number of patents were filed for heating of flowable materials.

In the twentieth century ohmic heating was practice in and off: first in the 1930s for electric pasteurization of milk, and later in the 1980s and 1990s for continuous flow sterilization and aseptic packaging for solid–liquid food mixtures.
Food processing of Ohmic heating