2.5.1. DPPH-Radical Scavenging Activity (DPPH-RSA) Assay

The DPPH (2,2-diphenyl-1-picrylhydrazyl)-RSA assay is based on the bleaching of this radical under the presence of antioxidant-containing extracts. Thus, the DPPH-RSA activity of algae extracts was measured spectrophotometrically at 517 nm, against the stable nitrogen radical DPPH. In this technique, 25 µL of algae extracts were mixed with 200 µL of fresh DPPH ethanolic solution (40 mg/L) and let stand for 30 min in the dark. Results were expressed as Trolox equivalent (TE) per g of the dry extract [21]. Determinations were conducted in triplicate.