The encapsulation of low viscosity omega-3 rich fish oil in polycaprolactone by supercritical fluid extraction of emulsions

Abstract

Supercritical fluid extraction of emulsions technology (SFEE) was used to encapsulate a liquid lipophilic compound, specifically fish oil rich in ω-3 polyunsaturated fatty acids. Three different emulsion formulations containing stabilizing agents were tested using Tween 80 as a surfactant, polycaprolactone as a coating polymer and acetone as an organic solvent. Spherical and non-aggregated nanoparticles with sizes ranging from 6 to 73nm were obtained, depending on the formulation. The nanoparticle encapsulation efficiency produced by SFEE was around 40%, similar to that generated by conventional solvent evaporation. Operating at 8.0MPa and 313K, less than 25kg CO2·kg acetone−1 were required to reduce the acetone concentration in the nanoparticle suspension to 5000ppm (pharmaceutical requirements). However, to obtain nanoparticles for use in the food industry (maximum acetone concentration of 50ppm), CO2 consumption required being increased to 127kg CO2·kg acetone−1.