Electrohydrodynamic drying of fruit slices: Effect on drying kinetics, energy consumption, and product quality

The effect of electrohydrodynamic drying on the drying kinetics, energy consumption, and quality was studied for apple and strawberry slices with different thicknesses from 1 to 4 mm. Effective diffusivity and energy consumption were quantified via direct measurements, whereas visual quality attributes, such as color and shrinkage, were determined through image analysis. It was found that effective diffusivity was independent of thickness, around 0.5 x 10(-11) m(2)/s for apples and 0.24 x 10(-11) m(2)/s for strawberries. The average specific energy consumption increased with the fruit thickness from 601.13 kJ/kg (1 mm) to 1433.83 kJ/kg (4 mm) for apple slices and from 1324.17 (3 mm) to 1756.71 kJ/kg (4 mm) for strawberry slices. The effect of EHD drying on apple color was significantly smaller than conventional hot air drying. The impact of EHD drying on the shrinkage of apple slices was about 85%, and for strawberry slices, about 90%, which was higher than in hot air drying. It can be concluded that EHD is effective for drying thin fruit slices due to the low energy consumption and better quality. Novelty impact statement The main advantage of EHD drying over conventional drying techniques is its low energy consumption and better product quality, which is beneficial for the commercialization of the technique. In this study, the effect of fruit thickness on drying kinetics, energy consumption, and product quality were evaluated for apple and strawberry slices. The specific energy consumption increased with thickness and was very low compared to thermal drying. EHD dried fruit slices had better visual quality than thermal drying.