Novel hybridized drying methods for processing of apple fruit: Energy conservation approach

Strategic outlook of apple cultivation and its significant post-processing challenges have been the leading factors for energy and time saving research approaches in apple processing. In this research, apple slices were subjected to hot air flow, microwave radiation and combined microwave-hot air flow drying. Drying time, energy consumption and thermal efficiency at different microwave power levels (500 W, 1000 W, 1500 W and 2000 W), hot air temperatures (40 °C, 50 °C, 60 °C and 70 °C) and inlet air velocities (0.5 ms−1, 1 ms−1, 1.5 ms−1 and 2 ms−1) were studied and compared. The minimum time of processing was 17 min when integrated hot air flow and microwave radiation was applied with 2000 W power at the temperature of 70 °C and air velocity of 2 ms−1. Furthermore, the minimum value of total energy consumption during entire process of apple slices drying was 2684 kJ which belonged to microwave drying with 2000 W power.