Microemulsion versus emulsion as effective carrier of hydroxytyrosol

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 137; no. 1; pp. 146 - 151
• Main Authors: Chatzidaki, Maria D., Arik, Nehir, Monteil, Julien, Papadimitriou, Vassiliki, Leal-Calderon, Fernando, Xenakis, Aristotelis
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2016
• Subjects: Antioxidant activity; Carriers; Chemistry; DLS; Drug Carriers; Dynamical systems; Dynamics; Electron Spin Resonance Spectroscopy; Emulsion; Emulsions; EPR; Heat treatment; Hydroxytyrosol; Kemi; Microemulsion; Microemulsions; Phenylethyl Alcohol - administration & dosage; Phenylethyl Alcohol - analogs & derivatives; Scavenging; Surface-Active Agents - chemistry; Surfactants; Hydroxytyrosol; DLS; Emulsion; Microemulsion; EPR; Antioxidant activity
• ISSN: 0927-7765; 1873-4367; 1873-4367
• DOI: 10.1016/j.colsurfb.2015.04.053

•Two edible W/O dispersions, an emulsion and a microemulsion, were formulated.•Medium Chain Triglycerides were used as the continuous phase.•Hydroxytyrosol (HT), the main hydrophilic antioxidant of olive oil was encapsulated.•Dispersions were characterized in terms of droplet size and interfacial properties.•A comparative study for the scavenging activity of encapsulated HT was assessed. 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.