Drying Kinetics and Energy Consumption in the Dehydration of Pomegranate (Punica granatum L.) Arils and Rind

The objective of this study was to evaluate the drying kinetics and energy requirements during convective drying (CD) (50, 60 or 70 A degrees C), vacuum-microwave drying (VMD) (240, 360 or 480 W) and a combined method of convective pre-drying and vacuum-microwave finishing drying (CPD-VMFD) while processing pomegranate arils and rind. Drying kinetics of CD and VMD was described using seven basic drying models; however, VMFD was modeled only by the Henderson and Pabis equation. Pomegranate rind required less drying time (26-460 min) than arils (51-1,395 min) due to its higher porosity and lower sugar content. The drying time and the energy consumption were reduced when the air temperature and microwave wattage were increased. VMD required less energy than CD within the entire range of moisture content assayed. CD energy consumption can be reduced by its combination with VMD (CPD-VMFD), and this reduction was more important when the VMFD was applied earlier. VMD and CPD-VMFD are a good option for food drying industry in order to reduce both the drying time and the energy consumption while processing pomegranate arils and rind. Therefore, industries can optimise the drying process and consequently save their financial needs.