EN
Seaweeds are the largest and most complex marine algae, which are taxonomically classified under three groups namely: brown algae, red algae and green algae. Sargassum fluitans is a genus of brown macro-algae, which are always found in abundance, floating on the sea. In this study, fucoidan and alginate were extracted from Sargassum fluitans, and their anti-oxidant and functional qualities were determined. Fucoidan and alginate extraction was carried out using hot Mcllvains buffer at 60 ⁰C. The test parameters monitored were the anti-oxidant activity (DPPH scavenging activity, hydroxyl radical scavenging activity, metal chelating and reducing power) and functional properties (water holding capacity, water swelling capacity, bulk density and water solubility index). The fucoidan and alginate yield from Sargassum fluitans was 11.12% and 13.11% respectively. The antioxidant properties (IC50) of fucoidan were compared to ascorbic acid and gallic acid as standards. The results of the functional properties of water holding capacity, oil holding capacity, water swelling capacity, emulsifying activity and bulk density of fucoidan and alginate are (1.153±0.10 g/g and 2.65±0.43), (1.67±0.25 and 2.11±0.34), (2.73±0.12 only for fucoidan), (80% and 89%), and (10±0.0.00 ± 0.62±0.00) respectively. The IC50 of fucoidan and alginate for hydrogen peroxide scavenging, metal chelating, hydroxyl radical scavenging, reducing power, and DPPH scavenging activities were (0.056±0.00 and 0.57±0.00), (0.069±0.00 and 0.081±0.00), (0.075±0.00 and 0.058±0.00), (0.101±0.00 and 0.078±0.04), and (0.058±0.00 and 0.073±0.00) respectively. Data from this study was carried out in triplicate and expressed as Mean ± SD, A p-value < 0.05 was considered significant. Results from the anti-oxidant activities of the extracts showed the following; the hydrogen peroxide scavenging activity of alginate and fucoidan is greater than that of ascorbic acid, the metal chelating activity of gallic acid is higher than fucoidan and alginate, the DPPH scavenging activity of fucoidan is greater than that of ascorbic acid. It was evident that fucoidan and alginate could serve as functional food source due to their functional properties and could serve as potential antioxidant sources.