title: Synchrotron radiation macrobeam and microbeam X-ray diffraction studies of interfacial crystallization of fats in water-in-oil emulsions.
abstract: Using macrobeam and microbeam techniques, we performed synchrotron radiation X-ray diffraction (SR-XRD) analyses of fat crystallization in water-in-oil (W/O) emulsion, in combination with DSC and polarized optical microscopic observation. Particular focus was on the crystallization of the fats around water droplets in the W/O emulsion systems using food emulsifiers of polyglycerol polyricinoleate (PGPR) alone (PGPR emulsion), and PGPR and monobehenoylglycerol (MB) (PGPR+MB emulsion). We obtained the following results: (1) macrobeam SR-XRD confirmed that adding MB promoted fat crystallization during cooling, (2) microbeam SR-XRD indicated that the lamellar planes of fat crystals near the water and oil interfaces are arranged almost parallel to the interface planes in both PGPR emulsion and PGPR+MB emulsion, and (3) adding MB resulted in the formation of tiny fat crystals because it promoted crystallization, which occurred both in the bulk oil phase and at the W/O interfaces. The present study is the first to apply microbeam SR-XRD to observe the microscopic features of fat crystallization in W/O emulsion, following fat crystallization in the oil droplets in the oil-in-water (O/W) emulsion (Arima, S.; Ueno, S.; Ogawa, A.; Sato, K. Langmuir 2009, 25, 9777-9784).
authors.affiliation: Nutrition and Health, Danisco/DuPont, Brabrand, Denmark.
authors.forename: Paul
authors.initials: P
authors.lastname: Wassell
authors.forename: Airi
authors.initials: A
authors.lastname: Okamura
authors.forename: Niall W G
authors.initials: NW
authors.lastname: Young
authors.forename: Graham
authors.initials: G
authors.lastname: Bonwick
authors.forename: Christopher
authors.initials: C
authors.lastname: Smith
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Sato
authors.forename: Satoru
authors.initials: S
authors.lastname: Ueno
mesh_terms: D003460:Crystallization; D004655:Emulsions; D005227:Fatty Acids / Q000737:chemistry*; D009821:Oils / Q000737:chemistry*; D055620:Optical Phenomena; D053838:Scattering, Small Angle; D017356:Synchrotrons; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000295:instrumentation*
chemical_list: D004655:Emulsions; D005227:Fatty Acids; D009821:Oils; D014867:Water