mL aliquot of samples (0.1, 1.0 and 1.5 mg.ml-1)
containing different extracts. The readings were
taken on a spectrophotometer at 517 nm, 30 minutes
after the start of the reaction. All determinations
were performed in triplicate and include a control
(no antioxidant). The decline the reading of optical
density of the samples was correlated with the control,
establishing the percentage of DPPH discoloration.
Allowing calculate, after the establishment of the
equilibrium of the reaction, the amount of antioxidant
spent to reduce DPPH 50% (EC50 value) (BrandWilliams
et al., 1995).