title: Localized lipid autoxidation initiated by two-photon irradiation within single oil droplets in oil-in-water emulsions.
abstract: The initiation of lipid autoxidation within single oil droplets in Tween-20-stabilized oil-in-water emulsion was achieved by highly focused two-photon (2P) irradiation at excitation wavelength (λex) 700 nm. The radical formation was enhanced by inclusion of the photo-cleavable radical initiator di-tert-butyl peroxide (DTBP) into the droplets, and demonstrated with confocal microscopy using radical-sensitive probe BODIPY(665/676). The radical chain reactions progressed up to 60 μm; however, there were no indications of oxidation in neighboring droplets demonstrating that radicals and oxidized probe molecules were not able to migrate between oil droplets. In addition, the spatial propagation of lipid autoxidation increased with the degree of oil unsaturation.
authors.affiliation: Max Rubner-Institut, E.-C.-Baumann-Straße 20, D-95326 Kulmbach, Germany; Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors.forename: Piret
authors.initials: P
authors.lastname: Raudsepp
authors.affiliation: Max Rubner-Institut, E.-C.-Baumann-Straße 20, D-95326 Kulmbach, Germany; Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors.forename: Dagmar A
authors.initials: DA
authors.lastname: Brüggemann
authors.affiliation: Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors.forename: Jes C
authors.initials: JC
authors.lastname: Knudsen
authors.affiliation: Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark. Electronic address: mola@food.ku.dk.
authors.forename: Mogens L
authors.initials: ML
authors.lastname: Andersen
mesh_terms: D004655:Emulsions; D008055:Lipids / Q000737:chemistry*; D009821:Oils / Q000737:chemistry*; D010084:Oxidation-Reduction; D014867:Water / Q000737:chemistry*
chemical_list: D004655:Emulsions; D008055:Lipids; D009821:Oils; D014867:Water
keywords: BODIPY(665/676); CLSM; Lipid oxidation; Oil droplet; Radicals; Two-photon irradiation