EVALUATION OF ANTIOXIDANT ACTIVITY BY STABILIZATION OF VITAMIN A AND CAROTENE

Abstract

Accelerated tests for antioxidant activity are described which depend on the protection of vitamin A concentrates (in ethylene dichloride solution) against ultraviolet irradiation, and on the protection of carotene (in mineral oil solution) against heat and aeration. The protection of vitamin A was influenced by light-filtering effects; the carotene method appeared to be more generally useful. The stabilizing power of wheat-germ oil for both solutions of Vitamin A and carotene against light is partly due to a screening effect by pigments. Some of the protection is also due to other components of the wheat-germ oil, but it is not known whether these function as stabilizers against light according to the usual theories of antioxidant action. Light-accelerated decomposition of vitamin A and carotene appeared more suitable for special tests than for general evaluation of antioxidants; stability experiments in the absence of light gave a more generally applicable picture of antioxidant activity.