Multi‐length‐Scale Elucidation of Kinetic and Symmetry Effects on the Behavior of Stearic and Oleic TAG. I. SOS and SSO. (31st December 2013)

• Record Type: Journal Article
• Authors: Baker, Mark; Bouzidi, Laziz; Garti, Nissim; Narine, Suresh S.
• Is Part Of: Journal of the American Oil Chemists' Society. Volume 91:Number 4(2014)
• Page Start: 559
• Page End: 570
• Publication Date: 2013-12-31
• Subjects: Oleoyl‐distearoyl triacylglycerols -- SOS -- SSO -- Polymorphism, DSC -- Thermal behavior -- Solid fat content -- Polarized light microscopy -- Microstructure -- Kinetics -- Crystallization; Oils and fats -- Periodicals; Soap -- Periodicals; Fats -- Periodicals; Food-Processing Industry -- Periodicals; Acides gras -- Périodiques; Aliments -- Industrie et commerce -- Périodiques; Huiles et graisses -- Périodiques; Savon -- Périodiques; Oliën; Chemie; Oils and fats; Soap; Periodicals; 547.77
• DOI: 10.1007/s11746-013-2404-z
• Languages: English
• ISSNs: 0003-021X

Abstract

Abstract: Positional isomerism in triacylglycerols (TAG), present in a molecular ensemble arising from genetic, environmental or processing‐induced changes, can result in significant differences in the macroscopic physico‐chemical functionality of crystallized networks of the ensemble. The differences in phase behavior induced by positional isomerism and levels of unsaturation of pure oleoyl‐distearoyl TAG (SOS, SSO) were detailed at different length scales. The effect of cooling rate on the polymorphism, thermal properties and microstructure were systematically investigated between 0.1 and 5 °C/min. The symmetrical SOS presented a complex polymorphism and microstructure, which varied predictively with cooling rate. The crystal phases and transitions observed for this TAG are similar to those of cocoa butter. In contrast, the cooling rate had limited effect on the phase behavior of the asymmetrical SSO. The differences between the crystallization of SSO and SOS induced by kinetics are related to the kinked oleic acid at the outer position in the SSO molecule and favorable end group structure for SOS. The fundamental understanding gained from such model systems can be used in many industrial formulations, particularly foods.