Levels in food Antioxidant

fruits , vegetables sources of antioxidant vitamins a, c , e

antioxidant vitamins found in vegetables, fruits, eggs, legumes , nuts. vitamins a, c, , e can destroyed long-term storage or prolonged cooking. effects of cooking , food processing complex, these processes can increase bioavailability of antioxidants, such carotenoids in vegetables. processed food contains fewer antioxidant vitamins fresh , uncooked foods, preparation exposes food heat , oxygen.

other antioxidants not obtained diet, instead made in body. example, ubiquinol (coenzyme q) poorly absorbed gut , made through mevalonate pathway. example glutathione, made amino acids. glutathione in gut broken down free cysteine, glycine , glutamic acid before being absorbed, large oral intake has little effect on concentration of glutathione in body. although large amounts of sulfur-containing amino acids such acetylcysteine can increase glutathione, no evidence exists eating high levels of these glutathione precursors beneficial healthy adults.

measurement , invalidation of orac

measurement of antioxidant content in food not straightforward process, antioxidants collectively diverse group of compounds different reactivities various reactive oxygen species. in food science, oxygen radical absorbance capacity (orac) once industry standard antioxidant strength of whole foods, juices , food additives. however, united states department of agriculture withdrew these ratings in 2012 biologically invalid, stating no physiological proof in vivo existed support free-radical theory or roles ingested phytochemicals, polyphenols. consequently, orac method, derived in vitro experiments, no longer considered relevant human diets or biology.

alternative in vitro measurements of antioxidant content in foods include folin-ciocalteu reagent, , trolox equivalent antioxidant capacity assay.