ORAC（Oxgen Radical Absorbance Capacity）

Oxygen radical absorbance capacity (ORAC) is a method of measuring antioxidant capacities in biological samples in vitro.^[1][2]

A wide variety of foods have been 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and legumes rated highly in extensive tables once published by the United States Department of Agriculture (USDA), but withdrawn in 2012 since no correlation between test results and biological activity could be determined,^[3] stating that no physiological proof in vivo existed in support of the free-radical theory.

Although not all have been unilaterally dismissive,^[4] the majority position supports the USDA decision.^[5] Alternative measurements include the Folin-Ciocalteu reagent, and the Trolox equivalent antioxidant capacity assay.