FREQUENCY AND TEMPERATURE DEPENDENCE OF THE DIELECTRIC PROPERTIES OF FOOD MATERIALS

An open–ended coaxial–line probe was used with network and impedance analyzers and a sample temperature control assembly, designed for use with the probe, to measure the dielectric properties of some food materials as a function of frequency and temperature. Graphical data for the dielectric constant and loss factor of a macaroni and cheese dinner preparation, whey protein gel, ground whole–wheat flour, and apple juice illustrate the diverse frequency– and temperature–dependent behavior of the dielectric properties of food materials.