The antioxidant, 2,2-diphenyl-1-picrylhydrazyl (DPPH), assay
was done according to the method of Brand-Williams, Cuvelier, and
Berset (1995) with some modifications. The stock solution was
prepared at 0.1 mmol/L with methanol and stored at 20 C until
needed. 100 mL of filtered juice in Whatman filter paper No. 1 were
mixed with 2.9 mL of the stock solution. After 1 h in the dark, the
absorbance was taken at 515 nm with a Visible Spectrophotometer
(Novaspec II, Biochrom Ltd., Cambridge, UK). The standard curve