Influence of the monoterpene α-pinene on the melting profile of triacylglycerols: a thermodynamic approach.

Triacylglycerols (TAGs) can form different structures in their solid phase affecting physical/sensorial properties of lipid-based products. Biocompounds, such as monoterpenes, can act as lipids' crystallization modifiers, modulating these properties, while the solid-liquid equilibrium (SLE) theory can broaden the understanding of the physicochemical mechanisms involved. This work evaluated SLE phase diagrams for binary mixtures composed of TAGs (trilaurin, tripalmitin, trimyristin) and α-pinene, main monoterpene found in several essential oils, unveiling how it influences fats' melting/crystallization characteristics. For this, DSC, microscopy, and thermodynamic modelling were applied. Results suggested formation of solid solutions (cocrystals), even at low α-pinene concentration, showing that it can modify TAGs' crystalline structures, their polymorphism, while increasing mixtures initial melting, decreasing biphasic states, improving stability. These findings are corroborated by strong molecular interactions observed for TAGs and α-pinene through thermodynamic modelling. α-Pinene proves to be a promising natural additive for lipid-based products, allowing properties' modulation.