Spray-congealing, a technique based on the fast solidification of sprayed molten lipids, is considered a novel strategy to encapsulate natural products. Among others, it is a safe, low cost, fast and reproducible technique, with rising interest for several applications (e.g. food applications). One of the key parameters for the application of this technique is the lipid solidification temperature, which can be modulated by optimizing the lipid composition. In this work, three lipid components (beeswax, carnauba wax, and medium-chain triglycerides (Miglyol 812)) were selected, and the mixture composition modelled using a simplex-centroid experimental design. Three different lipid compositions were chosen to validate the proposed model, then tested in the preparation of curcumin-loaded microparticles (1.5%, w/w). The produced microparticles were analysed in terms of colour, morphology, particle size, encapsulation efficiency and load, physicochemical, crystalline, and thermal properties. Results evidenced that microparticle's properties, including encapsulation efficiency, vary according to the used lipid mixture, supporting their tailoring role. This fact brings advantages in the design of microencapsulation systems based on spray congealing processes, broadening their applicability. Moreover, lipid composition optimisation was proved to be an important tool to precede the development of spray-congealing applications.
