To determine the radical scavenging potency of the
samples, which exhibited AA, we investigated them with an
experimental procedure that was adapted from Conforti et al
[33]. In an ethanol solution of DPPH radical (final
concentration was 1.0 × 10−4 M), test samples were added
at different concentrations. The reaction mixtures were
shaken vigorously and then kept in the dark for 30 minutes.
The absorbance of the resulting solutions was measured in
1-cm cuvettes using a Perkin Elmer Lambda 40 ultraviolet/
visible (UV/VIS) spectrophotometer (Perkin Elmer, Monza,
Italy) at 517 nm against the blank (without DPPH radical).
All tests were run in triplicate and the mean values
calculated. Ascorbic acid was used as a positive control.