Supercritical Carbon Dioxide Extraction and Characterization of Argentinean Chia Seed Oil

Abstract

Extraction of chia seed oil was performed with supercritical carbon dioxide (SC-CO2). 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-CO2 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 CO2 at 60 °C–250 bar to 28.8 g oil/kg CO2 at 60 °C–450 bar. The final extract obtained by SC-CO2 under different conditions and Soxhlet extraction contained mainly α-linolenic (64.9–65.6%) and linoleic (19.8–20.3%) acids. SC-CO2 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.