Connection between biological material drying characteristics and electrical properties

Abstract

The aim of this study was to measure the electrical properties of dried apricots, carrot slices during drying, wheat and maize grains; poppy, Amaranth, sunflower and rape oil seeds in dependence of moisture content, moisture ratio and temperature. Moisture content and moisture ratio of samples were studied. Among the electrical properties we determined conductivity, resistance, resistivity, capacitance, relative permittivity and impedance. We found out that the moisture ratio of samples decreases with time. During drying, the moisture content of the samples decreases according to quadratic function. The resistivity with temperature decreases, and conductivity with temperature increases exponentially. The resistivity decreases with increase of the moisture content. The permittivity of samples increases with temperature linearly. The permittivity decreases with the frequency, in this frequency range, and increases with the moisture content. The change of impedance magnitude in drying time showed good correlation with the change of moisture content.

Keywords

• biological materials
• electrical properties
• moisture ratio
• moisture content
• temperature