ABSTRACT
Dielectric properties of materials are those electrical characteristics that determine the materials’ interaction with electric elds. In radio-frequency (RF) and microwave heating of foods, and other dielectric materials as well, it is the interaction of the materials with the electric eld component of the electromagnetic waves that produces the desired heating effects. Strictly speaking, radio frequencies range from about 10 kHz to about 100 GHz, the frequencies practicable for radio transmission, spanning that portion of the electromagnetic spectrum between the audio frequencies and the infrared region (IEEE, 1990). Thus, the RF range includes those frequencies used for microwave heating. However, because RF dielectric heating applications were developed rst in the frequency range from about 3 to 40 MHz and microwave heating applications came later, there is a tendency, particularly in the food industry, to refer to the lower-frequency applications as RF dielectric heating and dielectric heating at microwave frequencies as microwave heating.
