title: Studies of isothermal crystallisation kinetics of sunflower hard stearin-based confectionery fats.
abstract: The crystallisation and polymorphic properties of three sunflower hard stearins (SHSs) and cocoa butter equivalents (CBEs) formulated by blending SHSs and palm mid fraction (PMF) were studied and compared with those from cocoa butter (CB), to explore their possibilities as confectionery fats. The isothermal crystallisation kinetics of these fats were examined by pNMR and DSC at three different temperatures. All samples studied displayed a two-step crystallisation profile that could be fitted to an exponential-Gompertz equation. Stop-and-return DSC studies showed that SHSs and CBEs exhibited different crystallisation mechanisms according to their triacylglycerol composition, with a quick formation of metastable crystals, followed by a polymorphic transition to the more stable β or β' forms. X-ray diffraction (XRD) was used to investigate the polymorphic forms of tempered SHSs and CBEs in the long term. In all cases the resulting fats displayed short spacing patterns associated with β polymorphism. These formulations based on SHSs and PMF met all the requirements to be considered as CBEs; therefore they could be used as an alternative to traditional confectionery fats.
authors.affiliation: Instituto de la Grasa (CSIC), Av. Padre García Tejero, 4, 41012 Sevilla, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Bootello
authors.forename: Richard W
authors.initials: RW
authors.lastname: Hartel
authors.forename: Madeline
authors.initials: M
authors.lastname: Levin
authors.forename: Jose M
authors.initials: JM
authors.lastname: Martínez-Blanes
authors.forename: Concepción
authors.initials: C
authors.lastname: Real
authors.forename: Rafael
authors.initials: R
authors.lastname: Garcés
authors.forename: Enrique
authors.initials: E
authors.lastname: Martínez-Force
authors.forename: Joaquín J
authors.initials: JJ
authors.lastname: Salas
mesh_terms: D003460:Crystallization; D005223:Fats / Q000737:chemistry*; D006368:Helianthus / Q000737:chemistry*; D007700:Kinetics; D013696:Temperature; D014280:Triglycerides / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D005223:Fats; D014280:Triglycerides; C022618:tristearin