A novel criterion for the evaluation of the contrast capacity of antioxidants toward lipid peroxidation

In order to overcome the uncertain derived from the different in vitro chemical-based assays described in literature to determine the antioxidant capacity of natural products, the oxygraphic method for the definition of a new criterion for assessing the contrast ability of antioxidants toward lipid peroxidation have been developed in aqueous micelle systems.The functional expression, based on the concept of competitive kinetics, is given by the ratio between the initial rates inferred from the oxygraphic traces monitored in the absence and in the presence of antioxidant. The value kA/k0[LH] with dimension mM-1, precisely describe the scavenging (or chain breaking) power of the studied antioxidants toward lipid peroxidation. Furthermore, we verified the possibility of use this method to create an absolute scale of antioxidant activity of molecules to apply also to more complex matrices, such as food (e.g. olive oil, wine), in order to establish a protocol for the determination of their antioxidant characteristics and protective action in conservation and human health.