antioxidant activity and total phenolic contents of persian gulf red algae, (hypnea hamulosa)

in this study antioxidant activity of the red algae (hypnea hamulosa) was investigated in the invitro condition. the measurement included total phenolic content, ferric reducing power, dpph radical scavenging activity and total antioxidant activity. seaweed samples with the ratio of 1:20 (algae: solvent) were extracted using conventional solvent extraction method for 24 hours. the applied solvents were pure water (100%) and organic solvents ‘i.e’ ethanol, methanol and acetone with the ratios of 30%, 50%, 70% and 100%. the results indicated that acetone extracts (50%) had the highest values in the total phenol contents, ferric reducing antioxidant power, dpph radical scavenging activity and total antioxidant activity with the values of 0.27, 0.06 mg tannic acid / g algal powder, 69.98% and 0.07 mg ascorbic acid/ g of dry algal, respectively. acetone 50% was the best solvents and ratio to determine antioxidant activity of this alga. from the results it can be concluded that the persian gulf red algae seems to be an appropriate species for phenolic extraction. however differences found in the antioxidant activity between solvent ratios may be related to the solvents polarity and biochemical properties of the algae.