title: Crystallization and transformation of polymorphic forms of trioleoyl glycerol and 1,2-dioleoyl-3-rac-linoleoyl glycerol.
abstract: This study examined the influence of different thermal treatments on the crystallization and transformation of trioleoyl glycerol (OOO) and 1,2-dioleoyl-3-rac-linoleoyl glycerol (OOL). Two triacylglycerol (TAG) samples were cooled at 0.5-15 °C·min(-1) and heated at 2 and 15 °C·min(-1). The polymorphic characteristics of the two TAGs were analyzed in situ using differential scanning calorimetry, Raman spectroscopy, and synchrotron radiation X-ray diffraction. Multiple polymorphic forms were identified in OOO (α, β'2, β'1, β2, and β1) and OOL (α, β'2, and β'1). Larger quantities of more stable forms (e.g., β2 and β1 of OOO and β'1 of OOL) were obtained when the samples were slowly cooled and heated. In contrast, less stable polymorphs were obtained with increased cooling and heating rates. Polymorphic transformations occurred in either solid-state or melt-mediation and were influenced by heating rates. The results were analyzed by considering the activation energies for crystallization and transformation of stable and less stable polymorphic forms in comparison with previous studies on 1,3-dipalmitoyl-2-oleoyl-glycerol and 1, 3-dioleoyl-2-palmitoyl-glycerol.
authors.affiliation: Departament de Cristal·lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès s/n, E-08028 Barcelona, Spain. laurabayes@ub.edu
authors.forename: Laura
authors.initials: L
authors.lastname: Bayés-García
authors.forename: Teresa
authors.initials: T
authors.lastname: Calvet
authors.forename: Miquel Àngel
authors.initials: MÀ
authors.lastname: Cuevas-Diarte
authors.forename: Satoru
authors.initials: S
authors.lastname: Ueno
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Sato
mesh_terms: D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D013059:Spectrum Analysis, Raman; D044366:Transition Temperature; D014280:Triglycerides / Q000737:chemistry*; D014304:Triolein / Q000737:chemistry*
chemical_list: C544957:1',3'-dilinolenoyl-2'-linoleoylglycerol; D014280:Triglycerides; D014304:Triolein