*2.9. ABTS and DPPH Scavenging*

Samples were analysed for antioxidant capacity through ABTS and DPPH tests [25]. For the first assay, 7 mM ABTS solution and 2.46 mM potassium persulfate were prepared and maintained for 18 h in the dark to obtain the radical molecule ABTS•+. The other test utilized a stable radical (1,1-diphenyl-2-picrylhydrazyl (DPPH)) dissolved in ethanol. Briefly, 0.1 mL of peptide solution (4 mg/mL) was added to 0.1 mL of 0.160 mM DPPH or 0.08 mM ABTS•<sup>+</sup> solution. The change of absorbance was estimated at 517 nm and 415 nm for DPPH and ABTS assay, respectively, with a plate reader (Infinite ® M200 PRO, Tecan, Männedorf, Switzerland). For ABTS test a calibration curve was set up using Trolox C as standard and results were expressed as Trolox Equivalent Antioxidant Capacity (TEAC). In the other assay, the results were indicated as percentage of antioxidant capacity inhibition (% DPPH scavenging).
