EXTRACTION OF ALKALOIDS FROM MICROWAVE DRIED ADATHODA VASICA LEAVES - A COMPARATIVE STUDY

Abstract

The effect of process parameters on the kinetics of microwave drying of Adathoda vasica leaves was studied. The variation of moisture ratio with time was tested with thin-layer empirical drying models. As Midilli’s expression gave better predictions for all data points than other models, it was expanded further. The microwave dried samples were subjected to microwave-assisted soxhlet extraction and microwave-assisted extraction. Moreover, the process variables considered in the present study had a significant effect on the extraction yield of alkaloids from A.vasica leaves. Though a higher extract yield of 40.28 % was achieved for microwave-assisted soxhlet extraction under optimal conditions (microwave output power of 100 W, sample load of 10 g and solid to solvent ratio of 1:20 g/ml) in 10 hours, the microwave-assisted extraction consumed a maximum duration of 1178 sec for 100 W of microwave output power and yielded 37.83 % of extract.