Algae. 2003; 18(1): 71-81.
Antioxidant Activity of Enzymatic Extracts from Brown Seaweeds
Soo-Jin Heo, Ki-Wan Lee, Choon Bok Song, You-Jin Jeon
Faculty of Applied Marine Science, Cheju National University
This work was carried out to find water-soluble natural antioxidants from seaweeds. Seven species of brown seaweeds (Ecklonia cava, Ishige okamurae, Sargassum fulvellum, Sargassum horneri, Sargassum coreanum, Sargassum thunbergii, and Scytosiphon lomentaria) growing along Jeju-Do coasts were collected and enzymatically hydrolyzed to prepare water-soluble products. Enzymes used were five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme, and Alcalase) commercially available from Novozyme Co. Antioxidant activities of enzymatic extracts from seaweeds were determined using two different assays, free radical scavenging activity by 1,1-diphenyl-2-pricrylhydrazyl (DPPH) decolorization assay and inhibitory capacity of lipid peroxidation in linoleic acid. Among all the enzymatic extracts enzymatically produced from the seven species of seaweeds, the enzymatic extracts of E. cava scavenged most effectively free radicals released from DPPH and especially Cellulast extract of E. cava caused around 80% scavenging activity at the extract concentration of 8 ㎎/ml. The antioxidant assay in terms of inhibitory capacity of lipid peroxidation revealed that Ultraflo and Alcalase extracts of E. cava and Neutrase extract of S. lomentaria had the highest inhibitory capacity. In particular it was noteworthy that the Neutrase extract of S. lomentaria had completely suppressed the lipid peroxidation during five days of the incubation period. In contrast to this result observed in the lipid peroxidation those extracts were shown to have poor radical scavenging activity. These results indicate that a large difference exists between the two antioxidant activity assays mentioned above. We demonstrated in the study that enzymatic extracts of seaweeds possess a potent antioxidant activity.
Keywords : antioxidant, enzymatic extract, lipid peroxidation, radical scavenging activity, seaweed