Antioxidant Activity Determination: FRAP and CUPRAC

For antioxidant activity determination, ferric reducing antioxidant power (FRAP) was used by [39 (link)] and cupric ion reducing antioxidant capacity (CUPRAC) by [40 (link)] with little modification. Briefly, for FRAP 10 μL of the extracted sample was mixed with 190 μL of FRAP (10 mM TPTZ; 20 mM FeCl₃, 6H₂O and 300 mM acetate buffer pH3.6; ratio 1:1:10 (v/v/v)) and for CUPRAC 10 μL of the extracted sample was mixed with 190 μL of CUPRAC (10mM Cu(II); 7.5 mM neocuproine and 1 M acetate buffer pH 7; ratio 1:1:1 (v/v/v)). Both of them incubated the reaction mixture for 15 min at room temperature (25 ± 2 °C). Absorbance of the reaction mixture was measured at 630 nm for FRAP, and 450 nm for CUPRAC by using a BioTek ELX800 Absorbance Microplate Reader (BioTek Instruments).