میترا احدی فر

Antioxidant are the main agents of neutralizing free radicals, which are active and harmful substances for humans The aim of this study was to investigate the antioxidant properties of aqueous extract of Sargassum vulgare brown algae collected from the shores of qeshm on a laboratory scale.

After collecting the algae from the shores of Qeshm and washing with fresh water extraction of Sargassum vulgare algae was performed then the desired extract was obtained in dry freeze dryer as a powder. the parameters of total Phenol, total antioxidant properties, free radical scavenging activity of DPPH, superoxide free radical, iron ion chelating ability and hyd roxyl radical were investigated in this study

According to the results the content of total phenol, total antioxidant activity, DPPH free radical, superoxide free radical percentage, iron ion chelating ability and hydroxyl radical in their highest concentrations equivalent to 16/22 mg of gallic acid per 100g of extract 521/70 mg of ascorbic acid per gram of extract, %24/08, %14/08 and %33/65 was calculated

Due to the high ability of Sargassum vulgare brown algae extract in antioxidant activities this algae extract can be introduced as a rich source of natural antioxidant compounds in food pharmceutical cosmetic and health industries

Alginates are polysaccharides found in brown algae having the most content in marine biopolymers. The present study investigates to extract the alginate using acidic method at PH=2 and comparing antioxidants activity of the extracted alginate at different concentrations from the brown macroalgae of S. vulgare and P. pavonica. According to results of the antioxidant measurement of total phenol content, free hydroxyl radical content, free, total antioxidant activity in three concentrations (20, 100, 200 mg/ml), free superoxide radicals in two concentrations (4.26, 41.45 µg/ml), chelating power in three concentrations (0.1, 0.5 and1 mg/ml), S. vulgare algae alginate was higher than P. pavonica algae alginate (P<0.05). Also, percentage of the free radical scavenging of DPPH was observed at a concentration of (150 µg/ml) by S. vulgare alginate and a concentration of (20 µg/ml) by algae alginate P. pavonica) P<0.05). No significant difference was found between the algae alginates in the reduction test in any of the concentration intervals) P>0.05). Due to the high antioxidants capacity of the studied alginates in this study, alginate can be introduced as a potential source of natural antioxidant compounds in the food, medical, cosmetic and health industries.

Sodium alginate is a cheap and available biopolymer due to its biodegradability and hydrophilic properties, PH sensitivity and natural nature received more attentions. Therefore, the present study investigates and compares the antioxidant properties of alginate in different concentrations of brown algae of Sargassum vulgare and Padina pavonica. According to the results, both algae had high antioxidant activity and the total amount of phenol antioxidant activity in three concentrations (100, 150 and 200 mg/ml), and chelating ability in three concentrations (0.1, 0.5 and 1 mg/ml) in Sargassum alginate were high. Ehereas the Padina alginate had a higher percentage of free radical scavenging DPPH, hydroxyl free radical at concentrations (0.11 and 1.83 mg/ml), regenerative power at the concentrations 160 and 320 µg/ml. There was no significant difference in the inhibition of free superoxide radicals between both algae at any concentration intervals(p <0.05).