Relationship between redox potential and chain-breaking activity of model systems and foods

The relationships between the redox potential and the chain-breaking activity of a glucose-glycine model system as well as of natural or heat-induced antioxidant-containing foods, when they undergo changes of their oxidative status, were studied. Results showed that redox potential may represent an interesting indicator of the antioxidant efficiency of food products when coupled with the determination of the chain-breaking activity. In fact, while chain-breaking activity measurements provide information on the capacity of antioxidant compounds to quench radicals, redox potential determinations give indications of the overall reducing properties of all the food antioxidants, including those which react slowly with radical species. The latter, in fact, could represent an antioxidant reservoir whose action is deferred during storage.