Antioxidant activity
The antioxidant activity was determined by DPPH method described by Blois (1958). One gram of sample was taken along with 29 ml methanol, shaken vigorously, and centrifuged at 5000 rpm for 15 min at 4 8C. To that filtrate 0.5 ml DPPH (Diphenyl picrylic hydrazine) reagent was added and incubat- ed for 45 min in dark. Methanol was taken as blank and 3 ml methanol with 0.5 ml DPPH reagent was taken as control. The absorbance was measured using spectrophotometer (Shi- madzu 1609, Tokyo, Japan) at 517 nm. The antioxidant activity was calculated using the following formula: Antioxidant activityð%Þ ¼ ðODcontrol À ODsampleÞ Â 100 ODcontrol