Abstract:
Four species of seaweed, Sargassum binderi Sonder, Amphiroa sp., Turbinaria conoides (J. Agardh) Kuzting and Halimeda macroloba Decaisne, were collected from the Gulf of Thailand. Seaweeds were extracted with water or ethanol and examined for phenolic compounds and antioxidant activities by measuring the scavenging activity of both ABTS and DPPH radicals. In general, the aqueous extracts (AE) showed higher antioxidant activities and phenolic contents than ethanolic extracts (EE). Therefore, AE were chosen for three additional assays: superoxide anion scavenging assay, anti-lipid peroxidation in liver homogenate and reducing power. T. conoides extract showed the highest antioxidation activity in all assays. Therefore, the dried T. conoides had a potential to antioxidative agent in nutraceutical products.