Sub- or Supercritical CO ₂ -Assisted Melting Point Depression of Free Fatty Acids and Triglycerides for Microencapsulation Processes in Sustainable Veterinary Applications

The process based on the particles from gas-saturated solutions (PGSS) using supercritical fluids offers a green alternative to conventional lipid-based encapsulation methods, which typically require higher thermal energy. This study presents experimental data including onset (first melting), completion (last melting), and freezing temperatures for the binary system formed by fatty acids and carbon dioxide at pressures range from 5 to 35 MPa. The results revealed notable melting point depressions across all tested compounds, with the greatest depression observed for myristic acid (Δ<i>T</i> = 16.36 K) at approximately 15 MPa. The completion (last melting) depression data were modeled by the means of the Peng-Robinson equation of state involving van der Waals mixing rule showing good agreement and providing understanding about the thermodynamic behavior of binary systems of fatty acids and triglycerides under pressurized carbon dioxide.