An automated photoinduced chemiluminescence method is described for the determination of the antioxidant capacity of water- and fat-soluble substances in food. Test kits available are those for the antioxidant capacity of water- and fat-soluble substances, the antioxidant efficacy of ascorbic acid, the urate-independent component of the antioxidative capacity of water-soluble substances, the antioxidative capacity of proteins, and the determination of superoxide dismutase. The method has high precision and very short measurement times. The method shows good to very good results compared with spectrophotometry and HPLC, resp.