Energy consumption and dehydration parameters of microwave drying of carrot

Abstract

The parameters of microwave dehydration (thickness, mass load, and microwave power level) of carrot slices had a statistically significant (P < 0.05) effect on the drying process. Carrot slices (thicknesses of 3, 6, and 9 mm) were dehydrated as monolayers at microwave power levels (80, 240 W) at different mass loads (1.00, 0.63, and 0.38 kg m^-2). The optimal microwave model for the carrot slice microwave dehydration was the model with the microwave power level of 240 W, mass load of 0.38 kg m^-2, and 3 mm thickness, with the shortest dehydration time (15 ± 1 minute) and the lowest energy consumption (0.099 ± 0.002 kWh). The minimum resistance to mass transfer (effective moisture diffusivity) was observed in the models with the thickness of 3 mm, a 1.00 kg m^-2 mass load, dehydrated at 80 W (8.2519 × 10^-8 ± 8.8815 × 10^-10 m² s^-1). The average activation energy for the analyzed models was 8.972 ± 0.009 W g^-1. Therefore, the application of the microwave dehydration method can be considered a proper alternative for the dehydration of carrot slices.