Dehydration Kinetics and Infusion Attributes of Microwave Dried Olive Leaves

Abstract

Olive leaves have been catching consumers‘ and researchers‘ great interest because of benefits on human health. In this study, the olive leaves were dried by microwave method at different powers (52, 90, 167, 290, 347 W real effective power levels) and drying kinetics of olive leaves were examined to find the best mathematical model. Page model was the most suitable model rather than the others. Diffusion coefficients were ranged between 2.65×10-10 to 6.87×10-10 m2/s and an increment in power level promoted moisture diffusivities. Dried olive leaves were used to get leave tea and different infusion temperatures were investigated to recover the total polyphenols (mg GAE/kg) and radical scavenging activities (%). Rising in infusion temperature, especially at 100°C enhanced the extraction levels of polyphenols from leave tea. Olive leaves dried at 167 W had higher phenolic contents (2282.9 mg GAE/kg) among all samples.