In this study, the Aloe vera gel (without drying adjuvant) can be spray dried using an inlet drying-air temperature greater than or equal to 200 °C and the outlet drying-air temperatures from 70 to 90 °C, in a fountain type arrangement. The drying-air temperatures can be classified into high or low drying temperature groups according to changes in the values of M, a_w, and T_g properties of the powders obtained, and assessed through the normal distribution density function. The GAB equation and the Gordon-Taylor model are useful tools to identify the effects of the drying-air temperature on the physical properties of dehydrated material, as well as to categorize if a spray drying temperature is low or high. However, it is important evaluate the prime thermolabile components of the gel, as well as the chemical changes observed, to achieve a better understanding of the relationship of these changes with the hygroscopic properties and transition phases of the powder product.
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