Comparative assessment of antioxidant activity and biochemical composition of four seaweeds, Rocky Bay of Abu Qir in Alexandria, Egypt

Abstract The current study estimated the antioxidant activity and biochemical composition of four seaweeds; Toania atomaria (Phaeophyta), Padina pavonia (Phaeophyta), Jania rubens (Rhodophyta) and Corallina elongate (Rhodophyta). The highest total antioxidant activity was observed with ethanol extract of T. atomaria (44.6 ± 1.6 mg ascorbic acid equivalents/g crude extract). Among the four seaweeds, ethanol extract of T. atomaria has recorded the highest value in ferric reducing antioxidant power (FRAP) assay (32.3 ± 0.0 mg ascorbic acid equivalents/g crude extract). The uppermost level of carbohydrates was (20.4% ± 0.4 and 19.5% ± 0.7 dry wt.) in P. pavonia and T. atomaria. Proteins were maximum (10.5% ± 0.6 and 8.0% ± 0.0 dry wt.) in P. pavonia and T. atomaria. The results detected that T. atomaria had the largest amounts of lipids (5.92% ± 0.09 dry wt.). The polyunsaturated ω6 essential fatty acids were recorded in T.atomaria, P. pavonia, and J. rubens (11.39%, 8.09%, and 6.28%), and ω3 essential fatty acids were recorded in T. atomaria and P. pavonia (0.65% and 0.97%). The seaweeds are interesting candidates for medicinal, pharmaceutical, and nutritional applications owing to their antioxidant activities, biochemical composition; they are not widespread in the coastal waters of Egypt and has few studies, especially T. atomaria.