title: Antioxidants and total peroxyl radical-trapping ability of olive and seed oils.
abstract: The presence of the oxidized and reduced forms of ubiquinones Q(9) and Q(10) was determined in commercial extra virgin olive and seed oils, where the amounts of alpha- and gamma-tocopherols and beta-carotene were also quantitated. Very high concentrations of ubiquinones were found in soybean and corn oils. Furthermore, the total antioxidant capability of each oil was evaluated by measuring total radical-trapping antioxidant parameters (TRAP) in tert-butyl alcohol and using egg lecithin as the oxidizable substrate. These values decreased in the order sunflower > corn > peanut > olive; the highest TRAP, which was found in sunflower oil, was related to the very high amount of alpha-tocopherol. Olive oil, because of the low content of alpha-tocopherol, exhibited a TRAP value approximately one-third that of sunflower oil. TRAP values of corn and soybean oils, in which low amounts of alpha-tocopherol but very high contents of gamma-tocopherol and reduced ubiquinones were present, were intermediate. gamma-Tocopherol exhibited a poor ability of trapping peroxyl radicals in tert-butyl alcohol. This behavior was probably due to the effects of the solvent on the rate of hydrogen abstraction from this phenol.
authors.affiliation: Dipartimento di Biochimica G. Moruzzi, Università degli Studi di Bologna, Via Irnerio, 48, 40126 Bologna, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Cabrini
authors.forename: V
authors.initials: V
authors.lastname: Barzanti
authors.forename: M
authors.initials: M
authors.lastname: Cipollone
authors.forename: D
authors.initials: D
authors.lastname: Fiorentini
authors.forename: G
authors.initials: G
authors.lastname: Grossi
authors.forename: B
authors.initials: B
authors.lastname: Tolomelli
authors.forename: L
authors.initials: L
authors.lastname: Zambonin
authors.forename: L
authors.initials: L
authors.lastname: Landi
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D010938:Plant Oils / Q000737:chemistry*; D013045:Species Specificity; D014451:Ubiquinone / Q000032:analysis; D024502:alpha-Tocopherol / Q000032:analysis; D024504:gamma-Tocopherol / Q000032:analysis
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D000069463:Olive Oil; D010545:Peroxides; D010636:Phenols; D010938:Plant Oils; D014451:Ubiquinone; C049375:perhydroxyl radical; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol; C025204:Ubiquinone Q2; C030571:ubiquinone 9