Drying of Gymnema sylvestre Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions

The leaf extracts of Gymnema sylvestre consist secondary metabolites which are well known for antioxidant activity. This study aimed to measure the drying characteristics G. leaves under far-infrared radiation (FIR) and optimize specific energy consumption activity ethanol-water extract dried leaves. Fresh were harvested exposed combinations four different temperatures (125, 150, 175 200 °C) exposure times (5, 10, 15 20 min). Drying kinetics, consumption, color changes, total phenolic content (TPC) activities quantified. Both temperature time have significant (p < 0.05) effects on equilibrium moisture was achieved at °C 18 min. decreased changes increased with temperature. Under lower (125 150 °C), TPC time, whereas higher (20 min) high (175 significantly highest 30.5 mg TAE/g leaf-fresh weight optimal conditions from dissimilarity function method 8.4