Activation Energy Kinetics in Thin Layer Drying of Basil Leaves

Basil leaves are well known for the medicinal values and grown widely in India. To investigate the effect of different drying conditions on activation energy kinetics of basil leaves, the solar and vacuum dryers were employed and air temperatures of 45, 55 and 65C were considered for the drying. Drying of basil leaves prominently occurred in falling rate period and it was found that basil leaves dried faster in solar dryer. The effective moisture diffusivity (Deff) of basil leaves increased with the increase in drying air temperature. The Deff values were higher for solar dryer than those dried in the vacuum dryer. . Effective moisture diffusivity of basil leaves ranged from 4.54 10-10 to 1.08 10-9 m2/s. An Arrhenius relation was employed to ascertain activation energy for the samples dried in both types of dryers and activation energy for basil leaves drying ranged from 38.54 to 20.32 kJ/mol.