The ORAC method (oxygen radical absorbance capacity) determines the antioxidant capacity of a food or food supplement, assigning it a value, called "ORAC value", in order to classify it. This method, which is used by the USDA (United States Department of Agriculture), selects foods with high antioxidant capacity, measures the capacity of a molecule to combat the free radicals that affect the biochemical balance of the components of our cells, key to the health of our bodies and to combating the contributors to cellular ageing.