title: Understanding solid-state properties of triglycerides used in pharmaceutical and food microencapsulation.
abstract: Hydrophobic materials, in particular hydrogenated vegetable oils, HVO, are extensively used as coating materials in food and pharmaceutical systems. Correct application of these coatings requires an evaluation of their behaviour as a function of various parameters such as melting temperature, solubility, concentration and/or pH. The purpose of this study was to assess the physico-chemical properties of an HVO in terms of composition, crystallisation, phase transition and polymorphism using a variety of analytical techniques, such as electrospray mass spectrometry (ESI-MS), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). High-resolution ESI-MS allowed establishment of the HVO main composition of long-chain triglycerides (average molecular weight 1183 Da). DSC results showed that thermal history determines the formation of at least two polymorphs of HVO, namely two different crystal forms, assigned as form α, melting point (m.p.) 48 °C, and form β', m.p. 60 °C. A third polymorph, the more thermodynamically stable β-form, having a melting point at 62 °C, is obtained by solution-mediated re-crystallisation. Phase transformation paths were investigated by isothermal DSC experiments, which evidenced that the α-form is kinetically stable at temperatures lower than 25 °C. These data are of particular interest in practical applications such as spray freezing or pan coating where significant heat transfer phenomena are involved.
authors.affiliation: Department of Pharmacy .
authors.forename: Lisa
authors.initials: L
authors.lastname: Elviri
authors.forename: Mattia
authors.initials: M
authors.lastname: Mangia
authors.forename: Roberta
authors.initials: R
authors.lastname: Menabeni
authors.forename: Andrea
authors.initials: A
authors.lastname: Della Bella
authors.forename: Claudia
authors.initials: C
authors.lastname: Camellini
authors.forename: Diego
authors.initials: D
authors.lastname: Beltrami
authors.forename: Lauro
authors.initials: L
authors.lastname: Arduini
authors.forename: Ruggero
authors.initials: R
authors.lastname: Bettini
mesh_terms: D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D004339:Drug Compounding; D005524:Food Technology; D044367:Phase Transition; D021241:Spectrometry, Mass, Electrospray Ionization; D014280:Triglycerides / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014280:Triglycerides
keywords: Analytical characterization; long chain triglycerides; phase transformation; polymorphism