Radio frequency treatment in food processing: A review of its recent applications in fluid and semifluid foods

Radio frequency (RF) treatment is an emerging technology that provides fast, volumetric, and deep penetrative heating effects, and it has been studied for various purposes in food processing. Among food products, fluid and semifluid foods, such as fruit juices, soup, milk, yogurt, minced meats, etc., which have a high moisture content (MC) and relatively uniform dielectric properties (DPs), exhibit better heating effects during RF treatment. Therefore, RF treatment of fluid and semifluid foods has attracted extensive attention in the last decade. This review provides an overview of applications of RF treatment in fluid and semifluid food processing, such as pasteurization, biochemical reaction promotion, bioactive compound extraction, enzyme inactivation, biological macromolecule modification, etc. The DPs of fluid and semifluid foods related to RF heating for different processing purposes, as well as RF heating uniformity and the typical RF equipment used in fluid and semifluid foods studies, are also summarized. Finally, the challenges and future directions of the RF processing of fluid and semifluid foods are discussed. As such, this review improves the understanding of RF heating of fluid and semifluid foods and promotes the application of RF technology in the food industry.