Antioxidant activity potential of gamma irradiated carrageenan.

The antioxidant capacity of irradiated κ-, ι-, λ-carrageenans were investigated using the hydroxyl radical scavenging assay, reducing power assay and DPPH radical scavenging capacity assay. The degree of oxidative inhibition increased with increasing concentration and dose. The type of carrageenan had also an influence on its antioxidant activity which followed the order of lambda<iota<kappa. Increase in oxidative property with radiation dose can be attributed mainly to the depolymerization of the carrageenans with corresponding increase in reducing sugar. The antioxidant properties of these carrageenan oligomers were lower than that of ascorbic acid and galactose sugar.