Reactive oxygen species (ROS) are generated as natural byproducts of the cellular metabolism. They are involved in various biological processes and act as important signal mediators. However, excess intracellular levels of ROS may result in cell and tissue damage and are therefore associated with degenerative diseases, most notably cancer. In healthy individuals, intracellular antioxidant systems serve to maintain ROS levels below a critical threshold, permitting essential ROS-mediated signalling processes to function, but preventing ROS overproduction and potential tissue damage. Cells that fail to compensate and neutralize heightened ROS levels die by apoptosis in order to avoid passing on ROS-caused DNA damage to daughter cells. Any dysfunction in the cellular antioxidant systems can have serious consequences1.
In addition to the cells’ own antioxidant systems, various studies have suggested a relationship between an antioxidant-rich diet and a good health status, implicating that the consumption of antioxidant-containing foods can help to maintain health and even prevent certain diseases2.
A well-established and reliable method to determine the antioxidant capacity of a substance is the oxygen radical absorbance capacity (ORAC) assay3. It is based on the inhibition of oxyradical-induced oxidation of 2,2´-azobis-(2-methylpropionamidine) dihydrochloride (AAPH) by substances with antioxidant properties. Peroxyl radicals produced in a time-dependent manner during the thermal decomposition of AAPH will quench the fluorescence signal. In the presence of a substance with antioxidant properties the fluorescence reduction is inhibited, depending on the substance’s ORAC capacity. The dynamics of the signal inhibition, expressed as the area under the curve (AUC), is used to quantitate the antioxidant capacity, expressed as the ORAC value, by comparing the sample AUC to an antioxidant standard curve generated with Trolox, a water-soluble vitamin E-analogue.
This note describes the performance of the ORAC assay on the Infinite F200 PRO, using different beverages as antioxidant samples.