Dehydration of Mango and Apple through Atmospheric Water Harvesting under Vacuum

Abstract

An adaptation of the concept of atmospheric water harvesting (AWH) with calcium chloride unsaturated aqueous solutions under vacuum (19 kPa absolute) and at ambient temperature (23 °C) was employed to dehydrate mango and apple. Under vacuum conditions, it was possible to remove 93–95% of the original water present in the raw fruits, and there was no statistically significant difference between fruit samples located at different distances from the desiccant source at the bottom of the system (P > 0.05). In contrast, when the dehydration was conducted at atmospheric conditions (100 kPa absolute), a significantly lower (P < 0.05) moisture removal was observed in the fruit samples that were more separated from the desiccant source. Colorimetric, infrared spectroscopy, and electron microscopy analyses showed that AWH under vacuum can dehydrate fruits, preserving color and slowing down multiple deterioration mechanisms.