[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of the free-radical theory or that ORAC provided information relevant to biological antioxidant potential, it was withdrawn in 2012.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.
The assay measures the oxidative degradation of the fluorescent molecule (either beta-phycoerythrin or fluorescein) after being mixed with free radical generators such as azo-initiator compounds.
Subsequently, the degree of antioxidant-mediated protection is quantified using the antioxidant trolox (a vitamin E analogue) as a standard.
[8][9] This guidance for the United States and European Union establishes it is illegal to imply potential health benefits on package labels of products with high ORAC.
[11] As interpreted by the Linus Pauling Institute, EFSA and the USDA, dietary polyphenols have little or no direct antioxidant food value following digestion.
[3][9][10][12] Not like controlled test tube conditions, the fate of polyphenols in vivo shows they are poorly conserved (less than 5%), with most of what is absorbed existing as chemically modified metabolites destined for rapid excretion.
"[13] Values are expressed as the sum of the lipid soluble (e.g. carotenoid) and water-soluble (e.g. phenolic) antioxidant fractions (i.e., “total ORAC”) reported as in micromoles trolox equivalents (TE) per 100 gram sample, and are compared to assessments of total polyphenol content in the samples.