Drying and diffusivity of melon seeds

Abstract

The melon seeds contain high water content after extraction, requiring drying to maintain their physiological qualities. The objective of this work was to model drying curves of melon seeds at different temperatures, to determine the effective diffusion coefficient and the activation energy. Drying was carried out under controlled conditions at temperatures of 35, 40, 45, and 50 °C using three replicates of 10 g of seeds, which were weighed periodically until reaching constant mass. The experimental data were adjusted to different mathematical models frequently used in the representation of seed drying. The effective diffusion coefficient, calculated from the mathematical model of net diffusion to spheroid prolat, was used to obtain the activation energy. The results showed that the Page model is the one that best fits the experimental data. The increase of the drying temperature reduces the drying time and promotes an increase of the effective diffusion coefficient. The relation of the diffusion coefficient to the drying temperature can be described by the Arrhenius equation, presenting an activation energy of 55.81 kJ mol-1 in the drying process of the melon seeds.