What is ORAC?

Oxygen radical absorbance capacity (ORAC) was a method of measuring antioxidant capacities in biological samples in vitro.^[1][2] Because no physiological proof in vivo existed in support of the free-radical theory or that ORAC provided information relevant to biological antioxidant potential, it was withdrawn in 2012.^[3][4]

Various foods were tested using this method, with certain spices, berries and legumes rated highly in extensive tables once published by the United States Department of Agriculture (USDA). Alternative measurements include the Folin-Ciocalteu reagent, and the Trolox equivalent antioxidant capacity assay.