Influence of Temperature on Drying Kinetics of Aloe vera and Its Mathematical Modeling

The drying characteristics and the effect of drying air temperature on hot air drying of aloe vera (Aloe barbadensis Miller) were investigated at 50, 60, 70 and 80°C. Five thin layer drying mathematical models (viz. Logarithmic, Newton, Henderson–Pabis, Page and Modified Page) were fit into the experimental moisture ratio for the kinetic study of aloe vera. Fick’s diffusional model and Arrhenius type of relationship were used to calculate the moisture diffusivity and activation energy respectively. The diffusivity coefficient increased from 1.03 x 10-09 to 1.55 x 10-09 m2 s-1 with the increase in temperature from 50 to 80°C with estimated activation energy and Arrhenius factor of 19.83 kJ mol-1 and 1.98 x 10-07 respectively. Henderson-Pabis model provided the best fit data and can be epitomized as an excellent tool for accessing the drying kinetics of Aloe vera.