title: Microemulsion versus emulsion as effective carrier of hydroxytyrosol.
abstract: Two edible Water-in-Oil (W/O) dispersions, an emulsion that remains kinetically stable and a microemulsion which is spontaneously formed, transparent and thermodynamically stable, were developed for potential use as functional foods, due to their ability to be considered as matrices to encapsulate biologically active hydrophilic molecules. Both systems contained Medium Chain Triglycerides (MCT) as the continuous phase and were used as carriers of Hydroxytyrosol (HT), a hydrophilic antioxidant of olive oil. A low energy input fabrication process of the emulsion was implemented. The obtained emulsion contained 1.3% (w/w) of surfactants and 5% (w/w) aqueous phase. The spontaneously formed microemulsion contained 4.9% (w/w) of surfactants and 2% (w/w) aqueous phase. A comparative study in terms of structural characterization of the systems in the absence and presence of HT was carried out. Particle size distribution obtained by Dynamic Light Scattering (DLS) technique and interfacial properties of the surfactants' layer, examined by Electron Paramagnetic Resonance (EPR) spectroscopy indicated the involvement of HT in the surfactant membrane. Finally, the proposed systems were studied for the scavenging activity of the encapsulated antioxidant toward galvinoxyl stable free radical showing a high scavenging activity of HT in both systems.
authors.affiliation: Institute of Biology Medicinal Chemistry & Biotechnology, National Hellenic Research Foundation, Athens, Greece; MTM Research Center, School of Science and Technology, Örebro University, Sweden.
authors.forename: Maria D
authors.initials: MD
authors.lastname: Chatzidaki
authors.affiliation: Institute of Biology Medicinal Chemistry & Biotechnology, National Hellenic Research Foundation, Athens, Greece.
authors.forename: Nehir
authors.initials: N
authors.lastname: Arik
authors.affiliation: Laboratoire Chimie et Biologie des Membranes et des Nanoobjets, Univ. Bordeaux, CBMN, Bordeaux, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Monteil
authors.affiliation: Institute of Biology Medicinal Chemistry & Biotechnology, National Hellenic Research Foundation, Athens, Greece.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Papadimitriou
authors.affiliation: Laboratoire Chimie et Biologie des Membranes et des Nanoobjets, Univ. Bordeaux, CBMN, Bordeaux, France.
authors.forename: Fernando
authors.initials: F
authors.lastname: Leal-Calderon
authors.affiliation: Institute of Biology Medicinal Chemistry & Biotechnology, National Hellenic Research Foundation, Athens, Greece; MTM Research Center, School of Science and Technology, Örebro University, Sweden. Electronic address: arisx@eie.gr.
authors.forename: Aristotelis
authors.initials: A
authors.lastname: Xenakis
mesh_terms: D004337:Drug Carriers; D004578:Electron Spin Resonance Spectroscopy; D004655:Emulsions; D010626:Phenylethyl Alcohol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D013501:Surface-Active Agents; C005975:3,4-dihydroxyphenylethanol; D010626:Phenylethyl Alcohol
keywords: Antioxidant activity; DLS; EPR; Emulsion; Hydroxytyrosol; Microemulsion