Simultaneous measurement of electrical and thermal properties: Application to margarine

Abstract
An experimental set-up for simultaneous measurement of thermal and dielectric properties of pasty materials, and in particular of margarine is proposed. The objective of the study was to observe simultaneously how the above mentioned properties change when margarine undergoes temperature changes within a temperature range that also encompasses its melting point. The PVDF pyroelectric sensor in combination with the plane plate capacitor was used for simultaneous measurement avoiding thereby problems arising from differences in both, sample's quantity and specific portion taken, the illumination level, heating, etc. As result of temperature variations both, the electrical and thermal properties of margarine were shown very sensitive to the structural changes. The reversibility of the modification process was observed. The results obtained with the set-up for simultaneous measurements were compared to those acquired by the methods capable of measuring each of the two properties separately.