title: Antioxidant Behavior of Olive Phenolics in Oil-in-Water Emulsions.
abstract: The effect of the surrounding molecular environment (β-lactoglobulin as an emulsion stabilizer and maltodextrin as a viscosity modifier) on the antioxidant activity of three olive oil phenolic compounds (PCs) in olive oil-in-water emulsions was investigated. Oxidation potential, phenolic partitioning, and radical quenching capacity were assessed in solution and in emulsion for oleuropein, hydroxytyrosol, and tyrosol; the influence of β-lactoglobulin and maltodextrin concentration was also evaluated. Finally, the observed properties were related to the oxidative stability of the emulsions containing the PCs to explain their behavior. The order hydroxytyrosol > oleuropein > tyrosol was observed among the antioxidants for both oxidation potential and radical quenching activity. Radical quenching capacity in emulsion and anodic potential were complementary indices of antioxidant effectiveness. As the intrinsic susceptibility of an antioxidant to oxidation expressed by its anodic potential decreased, the environmental conditions (molecular interactions and changes in continuous phase viscosity) played a major role in the antioxidant effectiveness in preventing hydroperoxide decomposition.
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari , Via Amendola 165/a, I-70126 Bari, Italy.
authors.forename: Vito Michele
authors.initials: VM
authors.lastname: Paradiso
authors.affiliation: Faculty of Bioscience and Technology for Agriculture, Food and Environment, University of Teramo , Via Balzarini 1, Campus Coste S. Agostino, 64100 Teramo, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Di Mattia
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari , Via Amendola 165/a, I-70126 Bari, Italy.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Giarnetti
authors.affiliation: Faculty of Bioscience and Technology for Agriculture, Food and Environment, University of Teramo , Via Balzarini 1, Campus Coste S. Agostino, 64100 Teramo, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Chiarini
authors.affiliation: Faculty of Bioscience and Technology for Agriculture, Food and Environment, University of Teramo , Via Balzarini 1, Campus Coste S. Agostino, 64100 Teramo, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Andrich
authors.affiliation: Department of Soil, Plant and Food Sciences, University of Bari , Via Amendola 165/a, I-70126 Bari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Caponio
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D031658:Olea / Q000737:chemistry*; D000069463:Olive Oil / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000975:Antioxidants; D004655:Emulsions; D000069463:Olive Oil; D010636:Phenols; D014867:Water
keywords: antiradical activity; cyclic voltammetry; o/w emulsions; olive phenolic antioxidants; oxidative stability