DIELECTRIC PROPERTIES OF MASHED POTATOES

Abstract

The dielectric properties of mashed potatoes are measured as a function of sample temperature and preparation procedure. The temperature range for the first sample is between 10 and 80°C, the second sample is characterised in the temperature range from −17.7 to 20.7°C. The results show, that the impact of temperature on the dielectric properties at 2.45 GHz is small in the range above the freezing temperature. In the temperature range, where melting occurs, there is a sharp increase of the relative dielectric constant ε′ and the loss factor ε′′. The measured, inter- and extrapolated values of the dielectric properties are used to calculate the penetration depth δ p . This parameter can serve as an input parameter for the mathematical modelling of temperature profiles in microwave heating of food of cylindrical and slab-shaped geometry.