Formation mechanisms of molecular compound in saturated‐unsaturated mixed‐acid triacylglycerols mixture systems and its edible applications

Abstract

The triacylglycerols (TAGs) containing saturated (Sat)‐unsaturated (U) fatty acid moieties (Sat‐U mixed acid TAGs) are widely present in most natural fats and employed in many industrial applications. The mixing behavior of different Sat‐U mixed acid TAGs acts important roles in the physicochemical properties TAG‐based materials. Among the three main mixing states of miscible, eutectic and molecular compound (MC) forming mixtures, fundamental research has been conducted on the MC crystals formed by different Sat‐U mixed acid TAGs to understand the structures, phase behavior and crystallization properties. This article reviews studies to date on the complex thermodynamic, kinetic and structural factors that affect the formation of MC crystals in binary and ternary mixtures of Sat‐U mixed acid TAGs (SatUSat, SatSatU, USatU and UUSat) through specific molecular interactions among the component TAGs. Furthermore, the application of the MC‐forming mixtures containing cacao butter to new types of cocoa butter alternative is reviewed.

Internal Factors Affecting the Crystallization of the Lipid System: Triacylglycerol Structure, Composition, and Minor Components

“…Because lipid systems often contain multiple types of TAG, the crystallization and physical properties are influenced by the combined effects of these TAG molecules [11]. The molecular interaction in TAG combinations can cause three types of phase behavior: miscible, eutectic, and molecular compound [57]. Macridachis-González, Bayés-García and Calvet [11] have reviewed the solid-state miscibility of binary and ternary systems.…”

“…Generally, MC in TAG systems results from a 1:1 ratio of saturated-unsaturated mixed-acid TAG components, organized in a well-defined manner within the crystal lattice. This stoichiometric compound displays distinctive structural and thermodynamic properties attributed to the specific molecular interactions among individual TAG molecules [57]. The formation of MC crystals is promoted by three key factors: conformational stabilization of the glycerol group, π-π interactions between the unsaturated fatty acid chains, and the stable arrangement of saturated and unsaturated chains [57].…”

“…This stoichiometric compound displays distinctive structural and thermodynamic properties attributed to the specific molecular interactions among individual TAG molecules [57]. The formation of MC crystals is promoted by three key factors: conformational stabilization of the glycerol group, π-π interactions between the unsaturated fatty acid chains, and the stable arrangement of saturated and unsaturated chains [57]. MC also exhibited unique properties in interaction with a third component, particularly with high-melting-point components.…”