Chemical composition antioxidant and antimicrobial activities of fucoidan extracted from two species of brown seaweeds (Sargassum ilicifolium and Sargassum angustifolium) around Qeshm Island

The chemical compositions, antioxidant and antimicrobial properties of fucoidan extracted from Sargassum ilicifolium and Sargassum angustifolium were investigated. The results showed that these seaweeds were characterized by an acceptable level of minerals and proteins. The fatty acid profile was dominated by the palmitic acid, which represents about 37.44±0.01% and 23.05±0.01% of the total fatty acids, followed by oleic acid (13.83±0.01% and 45.30±0.01%) for S. ilicifoliumand S. angustifolium, respectively. Swelling capacity, water holding capacity and oil holding capacity were varied in two different temperatures (25◦C and 37◦C).The antioxidant activities of fucoidan including DPPH, superoxide-hydroxyl radical scavenging, chelating ability and reducing power were considerable. The correlation of sulfate and phenol contents with scavenging superoxide radical ability, chelating ability and reducing power was positive. The antibacterial activity was evaluated by disc diffusion method against Bacillus subtilis and Staphylococcus aureus (gram positive bacteria) and Escherichia coli and Salmonella enteritidis (gram negative bacteria). There were no positive results against gram negative bacteria. In the concentration of 5 mg ml-1 small clear inhibition zones was observed against B. subtilis and S.aureus. On the basis of obtaining results from antioxidant activities, fucoidanis suggested as potential natural and safe antioxidant agents in the nutraceutical industry.