Ferric reducing ability of plasma (FRAP, also Ferric ion reducing antioxidant power) is an antioxidant capacity assay that uses Trolox as a standard. The FRAP assay was first performed by Iris Benzie and J. J. Strain of the Human Nutrition Research Group at the University of Ulster, Coleraine. It is often used to measure the antioxidant capacity of foods, beverages and nutritional supplements containing polyphenols.
^Benzie, Iris F.F.; Strain, J.J. (1996). "The Ferric Reducing Ability of Plasma (FRAP) as a Measure of "Antioxidant Power": The FRAP Assay". Analytical Biochemistry239 (1): 70–6. doi:10.1006/abio.1996.0292. PMID8660627.