Antioxidant activity of egg-yolk protein hydrolysates in a linoleic acid oxidation system

The antioxidant activities of egg-yolk protein hydrolysates in a linoleic acid system were investigated. Egg-yolk protein hydrolysates were prepared by enzymic hydrolysis of fat-free egg-yolk protein, which led to the main peak of the molecular mass distribution of lower than 1000. Egg-yolk protein hydrolysates showed strong antioxidant activity in a linoleic acid oxidation system as compared with the egg-yolk protein or amino acids mixture in which egg-yolk protein hydrolysates were constituted. The effect of the sample was concentration-dependent. Egg-yolk protein hydrolysates also showed strong antioxidant activities on cookies containing linoleic acid. These results suggest that egg-yolk protein hydrolysates could be a suitable natural antioxidant for preventing the oxidation of polyunsaturated fatty acids and related food ingredients. (C) 2003 Elsevier Ltd. All rights reserved.