Solid–Liquid Equilibrium of Binary Mixtures Containing Fatty Acids and Triacylglycerols

• Published in: Journal of chemical and engineering data Vol. 56; no. 8; pp. 3277 - 3284
• Main Authors: Costa, Mariana C, Boros, Laslo A. D, Souza, Jackiney A, Rolemberg, Marlus P, Krähenbühl, Maria A, Meirelles, Antonio J. A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.08.2011
• Subjects: Applied sciences; Biological and medical sciences; Chemical industry and chemicals; Chemistry; Composition, physical and chemical properties; Exact sciences and technology; Fat industries; Food industries; Fundamental and applied biological sciences. Psychology; General and physical chemistry; Liquid-solid equilibria; Oils and fats; Phase equilibria; Tripalmitin; Phase diagram; Triolein; Monounsaturated fatty acid; Polyunsaturated fatty acid; Lipids; Liquid solid equilibrium; Palmitic acid; Fatty acids; Glyceride; Linoleic acid; Binary mixture; Triacylglycerol; Saturated fatty acid; Oleic acid; Eutectic; Phase equilibrium
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/je200033b

Solid–liquid phase diagrams of the following systems were measured using differential scanning calorimetry (DSC): tristearin (2,3-di(octadecanoyloxy)propyl octadecanoate) + tripalmitin (2,3-di(hexadecanoyloxy)propyl hexadecanoate), tristearin (2,3-di(octadecanoyloxy)propyl octadecanoate) + palmitic acid (n-hexadecanoic acid), tristearin (2,3-di(octadecanoyloxy)propyl octadecanoate) + linoleic acid (cis-9,cis-12-octadecadienoic acid), tripalmitin (2,3-di(hexadecanoyloxy)propyl hexadecanoate) + triolein (2,3-bis[[(Z)-octadec-9-enoyl]oxy]propyl (Z)-octadec-9-enoate), and tripalmitin (2,3-di(hexadecanoyloxy)propyl hexadecanoate) + commercial oleic acid (commercial (Z)-octadec-9-enoic acid). The eutectic point was observed for two systems, tristearin with tripalmitin or with palmitic acid. Polarized optical microscopy was employed to investigate the solid phase of the systems and confirmed the occurrence of a solid solution at the extreme of the phase diagram rich in the component with a higher melting temperature. Margules-2-suffix, Margules-3-suffix, nonrandom two-liquid (NRTL), and universal quasichemical functional group activity coefficient (UNIFAC) models were employed to describe the liquidus line of the studied systems, except for the system formed by tripalmitin (2,3-di(hexadecanoyloxy)propyl hexadecanoate) + commercial oleic acid (commercial (Z)-octadec-9-enoic acid) which is a pseudobinary system that was well-described by the UNIFAC model. The best results for the other systems were obtained when employing the Margules-3-suffix and NRTL models.