The reducing power of the samples (FRAP), was determined by the
modified protocol described by Benzie & Szeto (1999) and Bub et al.
(2000), in a 96-well microtiter plate, following a similar procedure as
for DPPH. In this case the reaction was started by adding pre-warmed
FRAP reagent (200 μL, 37 °C), the absorbance was determined at a
wavelength of 593 nm and the reaction time was 8 min at 37 °C.