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Fractionation of pigments occurs over time during supercritical extraction of oil from natural matrices containing carotenoids. Paprika powder and paprika oleoresin were extracted using CO 2 at temperatures of up to 80°C and pressures up to 50 MPa. The pigment concentration in the supercritical phase was monitored with an on-line near infrared visible (NIR-VIS) detector. Concentrations of 90 to 200 g/kg total carotenoids were achieved in oleoresin extracted from starting material containing only 1.2 g/kg total carotenoids. The ratio of ß-carotene + free xanthophylls to total carotenoids in the recovered oleoresin diminished from nearly 50% (w/w) at the beginning down to 10% at the end of the extraction. Increased pressure improved kinetics of carotenoid extraction.

Extraction of chia seed oil was performed with supercritical carbon dioxide (SC-CO 2 ). To investigate the effects of pressure and temperature on the oil solubility and yield, two isobaric (250 and 450 bar) and two isothermal (40 and 60°C) extraction conditions were selected. The global extraction yield of chia oil increased with pressure enhancement, but temperature had a little influence on it. The maximum oil recovery using SC-CO 2 at a mass flow rate of 8 kg/h was 97%, which was obtained at 60°C, 450 bar for a 138-min extraction. The results showed that solubility changed from 4.8 g oil/kg CO 2 at 60°C-250 bar to 28.8 g oil/kg CO 2 at 60°C-450 bar. The final extract obtained by SC-CO 2 under different conditions and Soxhlet extraction contained mainly a-linolenic (64.9-65.6%) and linoleic (19.8-20.3%) acids. SC-CO 2 extraction is an interesting alternative methodology because it is possible to achieve a chia oil yield close to that obtained by conventional extraction with a similar fatty acid composition using an environmentally friendly process.

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