Ohmic Heating of Foods

Ohmic heating (OH) is an advanced thermal processing technology that employs electrical resistance to generate heat directly within food materials. This method relies on applying an alternating electrical current through the food, which serves as a conductive medium due to its inherent electrolytic properties. OH offers numerous benefits over conventional thermal processing, including uniform heating, reduced processing times, minimized thermal degradation of nutrients and sensory attributes, and higher energy efficiency. These benefits make it particularly suitable for processing heat-sensitive products like fruits, vegetables, and liquid-based foods. The technology is widely recognized for its potential to enhance food safety by inactivating pathogens and spoilage microorganisms while preserving food quality. Additionally, it facilitates innovative applications such as the pasteurization of particulate foods, enzyme inactivation, and the extraction of bioactive compounds. This chapter primarily focuses on the principles and fundamentals of OH, factors influencing the process, its applications in fruit and vegetable processing, enzyme and microbial inactivation, and its advantages and limitations.