Phase Equilibrium and Optimization Tools: Application for Enhanced Structured Lipids for Foods

Abstract

Abstract Solid–liquid phase equilibrium modeling of triacylglycerol mixtures is essential for lipids design. Considering the α polymorphism and liquid phase as ideal, the Margules 2‐suffix excess Gibbs energy model with predictive binary parameter correlations describes the non ideal β and β′ solid polymorphs. Solving by direct optimization of the Gibbs free energy enables one to predict from a bulk mixture composition the phases composition at a given temperature and thus the SFC curve, the melting profile and the Differential Scanning Calorimetry (DSC) curve that are related to end‐user lipid properties. Phase diagram, SFC and DSC curve experimental data are qualitatively and quantitatively well predicted for the binary mixture 1,3‐dipalmitoyl‐2‐oleoyl‐ sn ‐glycerol (POP) and 1,2,3‐tripalmitoyl‐ sn ‐glycerol (PPP), the ternary mixture 1,3‐dimyristoyl‐2‐palmitoyl‐ sn ‐glycerol (MPM), 1,2‐distearoyl‐3‐oleoyl‐ sn ‐glycerol (SSO) and 1,2,3‐trioleoyl‐ sn ‐glycerol (OOO), for palm oil and cocoa butter. Then, addition to palm oil of Medium‐Long‐Medium type structured lipids is evaluated, using caprylic acid as medium chain and long chain fatty acids (EPA‐eicosapentaenoic acid, DHA‐docosahexaenoic acid, γ‐linolenic‐octadecatrienoic acid and AA‐arachidonic acid), as sn ‐2 substitutes. EPA, DHA and AA increase the melting range on both the fusion and crystallization side. γ‐linolenic shifts the melting range upwards. This predictive tool is useful for the pre‐screening of lipids matching desired properties set a priori.