Ohmic Heating: A Review and Application in Food Industry

Abstract

Heat is used in many ways including in food processing. Heating methods are first used after the invention of electricity, include ohmic heating. This paper is written to review ohmic heating thoroughly in food industry, including the brief history, principle and its application. Ohmic heating is a development of conventional heating where it generates heat from alternate electrical current. In the process, the conductivity (σ = LI/ AV) plays a big role as it is used to spread the heat evenly and quickly. The ionic substance such as salts and sugar increase the conductivity. The basic principle of Ohmic Heating is the use of Ohm's law (R = V/I) because this technology is based on the electrical resistance of food. The world has developed with the growth of technology, ohmic heating used in many aspects of life including the food production commercially as it has many advantages that it is able to uniformly heats the product, low cost on maintenance, has high energy efficiency, able to produce high quality food and environmentally safer. The lack of general studies about ohmic heating also makes it difficult to control the system. It is also known ohmic heating is unable to work effectively for non-conductive foods. Regardless to the pros and cons, ohmic heating has been applicated commercially for pasteurizing, sterilizing, food thawing and blanching and fermentation.