Antioxidant activity of subcritical water extract (swe) of tamarind (tamarindus indica l) leaves

In the present work, a novel environmentally friendly technique, subcritical water extraction (SWE), is employed for the extraction of antioxidant compounds from Tamarindusindica leaves. For comparison, Tamarindus indica was also extracted by maceration method. Antioxidant activity of the extracts was evaluated using commonly accepted chemical 2, 2-Diphenyl-2-picrylhydrazyl radical scavenging; nitric oxide radical scavenging and total reducing power assays. In general antioxidant activity of subcritical water extract was found to be significantly higher than the extract obtained by maceration method.
Chemical composition of the extracts was determined in terms of total phenol content and total flavonoid content by colorimetric methods. Total phenolic content of Tamarindus indica leaves extracts estimated as gallic acid equivalent was found to be in the range 10.88– 19.57 mg/g of extract and flavonoid content estimated as rutin equivalent was found to be in the range 10.29 – 50.55 mg/g of extract.