Preparation of micro particles of functional pigments by gas-saturated solution process using supercritical carbon dioxide and polyethylene glycol

Particle design is presently a major development of supercritical fluids applications, mainly in the paint, cosmetic, pharmaceutical, and specialty chemical industries. The particles from the gas-saturated solutions (PGSS) process were used to micronize the functional compounds, fucoxanthin and astaxanthin. Fucoxanthin was extracted from brown seaweed using supercritical carbon dioxide (SC-CO₂) at 20 MPa and 45 °C. The particle formation of functional pigments with biodegradable polymer, polyethelene glycol (PEG) was performed by PGSS using SC-CO₂ in a thermostatted stirred vessel. Different temperatures (40 and 50 °C) and pressures (10–30MPa) were applied to optimize the conditions for the formation of functional pigment particles. Two nozzles of different diameter (250 and 300 μm) were used for PGSS and the reaction time was 1 hr. The average diameter of the particles obtained by PGSS at different conditions was about 0.78–1.42 μm.