Modeling and Investigation of Thermodynamic Indicators During Drying of Banana Slices in a Microwave Dryer

Abstract

Drying is a common method to prevent fruit spoilage and reduce fruit waste. It also makes it possible to store fruits for long periods of time. In this study, the drying behavior of banana fruit in a microwave dryer was investigated under different conditions. The main objective of this study was to evaluate the effects of different microwave powers (i.e., 100, 300, 500, and 700 W) on the drying kinetics, effective moisture diffusion coefficient (D_eff), energy efficiency (EE), and specific energy consumption (SEC) during drying banana slices. Also, changes in the moisture content (MC) of the samples during the drying process were measured and modeled using five thin-layer drying models. The results showed that increasing the speed and reducing the overall time of the banana slice drying process was associated with increasing the microwave power from 100 to 700 W. Fitting the experimental data using thin-layer drying models showed that the Midilli–Kucuk model gave the best results for describing the drying behavior of banana slices. The D_eff ranged from 0.068 × 10⁻⁷ to 1.19 × 10⁻⁷ m² s⁻¹. The lowest SEC and the highest EE were obtained at a microwave power of 500 W. These results provide useful information for determining the quality and monitoring the drying process of banana slices using microwave drying to save energy and time.