Ohmic Heating Technology Systems, Factors Governing Efficiency and Its Application to Inactivation of Pathogenic Microbial, Enzyme Inactivation, and Extraction of Juice, Oil, and Bioactive Compounds in the Food Sector

Ohmic heating (OH) is one of the promising food processing technologies which generates heat when an electric current passes through the food material directly. There are various key parameters affecting the rate and efficiency of ohmic heating which include the electric conductivity of the material, product size to be treated, heat capacity and heating rate of the system, material of electrodes, and combination of current intensities and voltage applied. All these parameters collectively contribute towards the development of an effective ohmic heating system. Nowadays, ohmic heating presents a wide range of applications in the inactivation of microorganisms, pathogenic bacteria, enzymes as well as in blanching, sterilization, enhancing juice and oil extraction processes. This review briefly describes the basic principles, process parameters, design, and concept of ohmic heating, along with the review of already existing and developed ohmic heating systems. Potential small-scale as well as commercial applications have also been reviewed along with highlighting the novelty and combination of ohmic heating with other processing techniques. Furthermore, the application of the ohmic heating system in the food sector like inactivation of microorganisms, enzymes, blanching, and extraction of juices and oil is described. In nutshell, this review article evaluated ohmic heating as an alternative to conventional heating methods. From the above-cited reviews, a conclusion has been drawn that ohmic heating is a faster method to uniformly heat the food product with a shorter duration/heating time and higher retention of nutritional and quality parameters along with higher energy efficiency. This review will be helpful in designing more effective ohmic heating systems and promoting their advanced applications in the food industry.