The antiradical activity of different samples was estimated according to the procedure reported by Yen and Chen (1995).
A 500 ll aliquot of the extract or trolox standard was added to 1 ml of methanolic solution of DPPH (74 mg/l).
A daily-prepared solution of DPPH gave a final absorption at 520 nm of 1.8 AU.
Mixture was shaken and allowed to stand for 1 h at room temperature, and then absorption was measured at 520 nm in a Lambda 25 spectrophotometer.