title: Interactions between flavonoids and proteins: effect on the total antioxidant capacity.
abstract: Flavonoids are potent antioxidants. It is also known that flavonoids bind to proteins. The effect of the interaction between tea flavonoids and proteins on the antioxidant capacity was examined. Their separate and combined antioxidant capacities were measured with the Trolox equivalent antioxidant capacity (TEAC) assay. It was observed that the antioxidant capacity of several components of green and black tea with alpha-, beta-, and kappa-casein or albumin is not additive; that is, a part of the total antioxidant capacity is masked by the interaction. This masking depends on both the protein and the flavonoid used. Components in green and black tea, which show the highest masking in combination with beta-casein, are epigallocatechin gallate and gallic acid. The results demonstrate that the matrix influences the efficacy of an antioxidant.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Medicine, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. Mariken.Arts@farmaco.unimaas.nl
authors.forename: Mariken J T J
authors.initials: MJ
authors.lastname: Arts
authors.forename: Guido R M M
authors.initials: GR
authors.lastname: Haenen
authors.forename: Lonneke C
authors.initials: LC
authors.lastname: Wilms
authors.forename: Sasja A J N
authors.initials: SA
authors.lastname: Beetstra
authors.forename: Chantal G M
authors.initials: CG
authors.lastname: Heijnen
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Voss
authors.forename: Aalt
authors.initials: A
authors.lastname: Bast
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D001628:Beverages; D002364:Caseins / Q000737:chemistry; D002417:Cattle; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology; D008892:Milk; D011392:Proline / Q000032:analysis; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013662:Tea
chemical_list: D000975:Antioxidants; D002364:Caseins; D005419:Flavonoids; D011506:Proteins; D013662:Tea; D012710:Serum Albumin, Bovine; D011392:Proline