The antioxidant activity of SCG extracts was measured by the
ferric reducing antioxidant power (FRAP) assay, which was performed according to the method described by Benzie and Strain
[19] with some modifications. A 10ll aliquot of filtered extract
was mixed with 290ll of FRAP reagent in a 96-well microplate,
and incubated at 37C for 15 min. After that, the absorbance was
determined at 593 nm using distilled water as blank. A calibration
curve was constructed using an aqueous solution of ferrous sulfate
(FeSO47H2O at 200, 400, 600, 800 and 1000lM). The FRAP values
were expressed as millimoles of ferrous equivalent per dry weight
of material (mM Fe(II)/g SCG)