Dehydration of aloe vera: simulation of drying curves and evaluation of functional properties Original Research Article

The effect of air-drying temperature (from 30°C to 80°C) on dehydration curves and functional properties (water retention capacity, WRC; swelling, SW; fat adsorption capacity, FAC) of aloe vera cubes has been investigated. A diffusional model taking into account sample shrinkage has been proposed and solved by using a finite difference method. The effective diffusivities estimated with the proposed model varied with the air-drying temperature according to the Arrhenius law except for the experiment carried out at 80°C, where case-hardening took place. Simulation of aloe vera drying curves by using the model was accurate (percentage of explained variance (%var): 99.7 ± 0.1%). Furthermore, drying kinetics of aloe vera cubes of different sizes to those used to develop the model could be satisfactorily predicted (%var: 99.5 ± 0.2%). The three studied functional properties exhibited a maximum when drying temperature was 40°C decreasing either at higher or lower temperatures.