Antioxidant activity of protein hydrolyzates from aquatic species

Antioxidant activity of protein hydrolyzates from capelin (Mallotus villosus) and harp seal (Phoca groenlandica) was examined in a beta-carotene/linoleate model system. Capelin protein hydrolyzates exhibited a significant (P < 0.05) antioxidant effect during the entire or a portion of the 120-min incubation period when added to model systems at 1 to 10-mg levels per 5 mt of lipid emulsion. However, systems containing 10 mg of seal protein hydrolyzate (SPH) displayed a significant (P < 0.05) prooxidative effect during the experimentation period, but the effect was less pronounced at 5 mg of SPH addition. This effect was reversed to a weak, bur significant (P < 0.05), antioxidant effect when 1 or 2 mg of SPH were present after 45, 105-120, and 30-120 min of incubation. Two-dimensional thin-layer chromatographic separation of both hydrolyzates gave spots with antioxidant and prooxidant activities.