title: Targeting excessive free radicals with peels and juices of citrus fruits: grapefruit, lemon, lime and orange.
abstract: A comparative study between the antioxidant properties of peel (flavedo and albedo) and juice of some commercially grown citrus fruit (Rutaceae), grapefruit (Citrus paradisi), lemon (Citrus limon), lime (Citrusxaurantiifolia) and sweet orange (Citrus sinensis) was performed. Different in vitro assays were applied to the volatile and polar fractions of peels and to crude and polar fraction of juices: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power and inhibition of lipid peroxidation using beta-carotene-linoleate model system in liposomes and thiobarbituric acid reactive substances (TBARS) assay in brain homogenates. Reducing sugars and phenolics were the main antioxidant compounds found in all the extracts. Peels polar fractions revealed the highest contents in phenolics, flavonoids, ascorbic acid, carotenoids and reducing sugars, which certainly contribute to the highest antioxidant potential found in these fractions. Peels volatile fractions were clearly separated using discriminant analysis, which is in agreement with their lowest antioxidant potential.
authors.affiliation: CIMO/Escola Superior Agrária, Instituto Politécnico de Bragança, Campus de Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal.
authors.forename: Rafaela
authors.initials: R
authors.lastname: Guimarães
authors.forename: Lillian
authors.initials: L
authors.lastname: Barros
authors.forename: João C M
authors.initials: JC
authors.lastname: Barreira
authors.forename: M João
authors.initials: MJ
authors.lastname: Sousa
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Carvalho
authors.forename: Isabel C F R
authors.initials: IC
authors.lastname: Ferreira
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology; D001628:Beverages / Q000032:analysis*; D002241:Carbohydrates / Q000737:chemistry / Q000494:pharmacology; D002338:Carotenoids / Q000737:chemistry / Q000494:pharmacology; D002957:Citrus / Q000737:chemistry*; D032082:Citrus aurantiifolia / Q000737:chemistry; D032083:Citrus paradisi / Q000737:chemistry; D032084:Citrus sinensis / Q000737:chemistry; D003124:Colorimetry; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D012015:Reference Standards; D019207:beta Carotene / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D016166:Free Radical Scavengers; D005609:Free Radicals; D010636:Phenols; D019207:beta Carotene; D002338:Carotenoids; D001205:Ascorbic Acid