Drying kinetics and energy efficiency of microwave-dried lemon slices

In the current study, lemon slices were dried at various microwave powers (120, 350, 460, 600 and 700 W) to determine drying characteristics and energy efficiency. Drying rate and time were significantly affected by increasing of microwave power. The lowest and highest drying time were 8 and 54 min at 700 and 120 W, respectively. As microwave power increase, drying rate increased and drying time decreased. Besides, the most suitable model to describe microwave drying curves of lemon slice was obtained as Page model. The values of Deff of the dried lemon slices were calculated between 3.61x10-9 and 3.41x10-8 m2s-1. The Ea of drying of the lemon slices were calculated by using Deff and rate constant obtained from the Page model as 4.39 Wg-1 and 6.04 Wg-1, respectively. Additionally, the higher cumulative energy efficiency, the lower specific energy consumption. The lowest specific energy consumption and the highest energy efficiency were calculated at 460 W. 460 W drying power was found the best power with 11 min of drying time, the highest energy efficiency and lowest specific energy consumption.