Phytochemical profiling and antioxidant capacity of Kappaphycus alvarezii (Doty) Doty collected from seaweed farming sites of tropical coastal environment

Abstract

The present study mainly focuses on analysing the phytochemical profiling and antioxidant activity of Kappaphycus alvarezii collected from seaweed farming site of Munaikadu coast at Palk Bay, southeast coast of India. The pigments (chlorophyll ‘a’ and ‘b’, total carotenoid and anthocyanin) and contents of biochemicals (total protein, lipid, carbohydrate, ash, moisture, agar, carrageenan and gel strength) were estimated during all four seasons. Chlorophyll ‘a’ was found to be higher (p < 0.05) in monsoon season, whereas an insignificant (p > 0.05) difference was noted in chlorophyll ‘b’ among all seasons. Secondary pigments like total carotenoid and total anthocyanin were recorded significantly higher (p < 0.05) during post-monsoon and summer seasons. The fatty acids, amino acids, total phenolic content, total antioxidant activity, DPPH radical-scavenging activity and lipoid peroxidation activity of K. alvarezii were measured in the present study. The fatty acids analysis showed that the linoleic acid was significantly higher (p < 0.05) in K. alvarezii, followed by oleic acid, palmitic acid and stearic acid. In amino acids analysis, the lysine level was significantly elevated (p < 0.05) in K. alvarezii, followed by leucine and isoleucine, proline, arginine, tyrosine, phenylalanine and glutamic acid. Significant (p < 0.05) increase in total phenolic content, total antioxidant activity, DPPH radical-scavenging activity and lipoid peroxidation activity was recorded in methanolic extraction of K. alvarezii compared with other solvents extraction.