2.2. Ferric Reducing Antioxidant Power (FRAP) Assay

To prepare the FRAP reagent, 2.5 ml of 10 mM tripyridyltriazine dissolved in 40 mM HCL, 2.5 ml of FeCl₃, and 25 ml of acetate buffer 0.3 M pH 3.6. The extract was dissolved in phosphate buffer (1 mg / ml). 0.2 ml of the extract solution and 1.8 ml of the fresh FRAP reagent were mixed; then the sample was incubated at room temperature for 30 minutes. The increase in absorbance was measured at 595 nm (6405, JENWAY). The FRAP value was calculated by performing a standard curve, using FeSO₄. The FRAP values were expressed as mM of FeSO₄ per gram of dry extract [14].