Antioxidant status of selected sea weeds of Manamelkudi coast, Pudukkottai district

Abstract

Manamelkudi, located along the Palk Strait of East coast of Tamil Nadu serve as treasure houses for valuable marine resources like sea grass and sea weeds. A study was undertaken at Agricultural College & Research Institute, Kudumiyanmalai during 2016-17 to evaluate the nutritional composition of the seaweeds in order to use them as potential food ingredients. Sea weed samples were collected from Manamelkudi village of Pudukkotai district and were identified as Gracilaria salicornia (C.Agardh) Dawson and Gracilaria edulis (S.G. Gmel.) P.C. Silva Gracilariaceae at Botanical Survey of India, Coimbatore. The samples were washed in sea and fresh water to remove associated organisms and other extraneous matters. The sea weeds were dried, powdered and used for assessing the antioxidant status. G. edulis showed higher activities of enzymic antioxidants superoxide dismutase (312.03 U/g) and catalase (50.1U/g) when compared to G. salicornia (SOD:266.27U/g and CAT:37.1U/g). Maximum levels of the non-enzymic antioxidants, (total phenol and flavonoid) was found in G. edulis when compared to G. salicornia (5.8 and 3.43mg/g; 5.23 and 3.3mg/g respectively). The extent of lipid peroxidation assessed revealed 70.5 and 32.1 percent inhibition by the ethanolic extract of G. edulis and G. salicornia respectively. The results were comparable with that of the standard antioxidant BHT. Phytochemical analysis revealed the presence of alkaloids, carbohydrates, saponins, proteins, aminoacids, phytosterols, phenolic compounds, flavonoids, terpenoids and tannins except saponins and terpenoids in G. salicornia. Thus it can be concluded from the present investigation that both the seaweeds are potentially rich in natural antioxidants and could be used as nutrient supplements in food industry.