The ABTS•+ scavenging test is used to determine the antioxidant activity of both hydrophilic and hydrophobic compounds. ABTS•+ is generated by mixing 2.5 mL of 7 mM ABTS with 2.5 mL of 14.7 mM potassium persulfate (KPS) water solutions and stored in the dark at room temperature for 16 h. The reaction between ABTS•+ and potassium persulfate directly generates the blue green ABTS•+ chromophore, which can be reduced by an antioxidant, thereby resulting in a loss of absorbance at 750 nm.