Kinetic parameters show a good fit according to the selected model. An increase in the kinetic constants with the Brix degrees was observed. Higher k values were found in the unpeeled aloe slices. The highest velocities of sugar gain were obtained for unpeeled samples at 40 °C with 35–50 °Brix solutions. Treatments with 65 °Brix solutions caused a reduction in sugar gain velocity in peeled or unpeeled samples. This effect can be related with shrinkage and deformation in parenchymatic cells. The De values obtained varied between 0.19 × 10−8 and 1.98 × 10−8 m2/s, increasing from 25 to 40 °C. The De values in the peeled aloe slices were higher that in unpeeled slices, which can be explained by the skin reducing about 50% of the total exchange surface in OD process. The highest coefficients corresponded to the peeled samples dehydrated at 40 °C with 35 °Brix solution due to its reduced viscosity that facilitate solute penetration.
Osmotic dehydration causes changes in the cellular size of the Aloe vera tissue. The phenomena observed during osmotic dehydration were shrinkage of cells, plasmolysis and folding of the cell walls which could explain the different behaviour between unpeeled and peeled Aloe vera slices during osmotic dehydration. The presence of skin in the Aloe vera slices promotes water loss, maintaining the structure of the slice, but reducing diffusivity.