The ORAC stands for Oxygen Radical Absorbance Capacity and rates foods according to their antioxidant content. When the National Institute on Aging in Baltimore developed this scale, it was revealed that a number of foods are especially high in antioxidants. Tropical fruits like acai and wolfberry .To enjoy fruits and vegetables which are ranked high on this scale can improve your body's ability to fight free radicals that cause the weakness and damage associated with aging.