Antioxidant capacity of dry sea cucumber Holothuria edulis, Pearsonothuria graeffei, and Stichopus herrmanni from Boalemo waters, Gorontalo, Indonesia

Abstract

Sea cucumber was a marine invertebrate from class Holothuroidea and phylum Echinoderm that possessed various bioactive compounds. This study aimed to estimate the antioxidant properties of sea cucumbers and evaluate their antioxidant ability. Ferric Reducing Antioxidant Power (FRAP) and Cupric Reducing Antioxidant Capacity (CUPRAC) assay estimated the antioxidant properties of sea cucumbers, and for control, ascorbic acid and Trolox were used. The samples were dried sea cucumber of Holothuria edulis, Pearsonothuria graeffei, and Stichopus herrmannii from Boalemo, Gorontalo. The three samples had various antioxidant capacities. H. edulis had the highest value, both in FRAP and CUPRAC assay, followed by P. graeffei and S. herrmanni. The FRAP values were 48.47; 28.32; and 11.95 μmol Fe(II), respectively and the CUPRAC values were 6.5; 5.9; and 1.49 μmol Trolox/g extract. The weak antioxidant properties of sea cucumber extract in both methods were most likely related to the absence of phenolic compounds which usually have OH groups and conjugated double bonds. Separation and purification of the crude extract may improve its antioxidant properties. Based on this research, it can be concluded that the antioxidant capacity of H. edulis, P. graeffei, and S. herrmanni using the FRAP and CUPRAC method was weak.