2.6. FRAP Assay

Ferric reducing ability of plasma (FRAP) was evaluated by a spectrophotometric assay as previously described [20]. The reaction mixture contained 225 μL of FRAP reagent (10 mmol/L TPTZ solution in 40 mmol/L HCl, 0.02 mmol/L FeCl₃·6H₂O and acetate buffer (pH 3.6), in a ratio 10:1:1), 22.5 μL of distilled water and 10 μL of each extract. After 6 min of incubation, the absorbance was measured, while reduction potential was calculated as milligrams of ascorbic acid equivalents (AAE) per gram of dry weight (mg AAE/g d.w.), calculated according to the standard calibration curve of ascorbic acid solution.