ABSTRACT

The application of radio frequency (RF) waves for drying, pasteurization, sterilization, disinfestation, and enzyme inactivation of foods is gaining popularity because of its advantages over conventional processing techniques. Although RF wave occupies a region between 1 and 300 MHz in the electromagnetic spectrum, the frequencies used for industrial heating lie in the range of 10-50 MHz. As these waves lie in the radar range and can interfere with communication systems, only selected frequencies (13.56 MHz ± 6.68 kHz, 27.12 MHz ± 160.00 kHz, and 40.68 MHz ± 20.00 kHz) are permitted for domestic, industrial, scientic, and medical applications. RF is considered to be a nonionizing radiation, as it does not have sufcient energy (less than 10 eV) to ionize biologically important atoms from materials exposed to it. Applications of RF in textile industries for drying of natural, articial, and synthetic bers and in paper industries for continuous web nishing, sheet web nishing, laminating, and book binding are reported (Pai et  al., 1989). In this chapter, the principle of RF heating, its comparison with conventional heating, and factors affecting RF heating are discussed. The effects of RF blanching, drying, pasteurization, sterilization, disinfestation, cooking, and freezing on nutritional quality, texture, color, sensorial attributes, volatile compounds, microstructure, and shelf life are also detailed.