ABTS radical scavenging test was carried out to evaluate the total antioxidant activity of cur@star in accordance with previous literature (Gomez-Mascaraque, Lagaron, & Lopez-Rubio, 2015). Stock solution was prepared by dissolving ABTS and potassium persulfate in distilled water at concentration of 7 mMand 2.45 mM respectively. The stock solutionwas left in dark place for 24 h before diluted with distilled water to an absorption of 0.70 ± 0.02 at 734 nm on a UVevis spectrometer. A small portion (0.1 mL) of curcumin ethanoic solution or sample solution at various concentrations was pipetted into a glass vial containing 1 mL of ABTS working solution, and the absorption at 734 nm was measured 1 min after the mixing. The same volume of distilled water was mixed with ABTS working solution in the same way to measure the blank absorption. ABTS radical scavenging ability was calculated by the following equation: