Large-scale supercritical carbon dioxide extraction and supercritical carbon dioxide countercurrent extraction of cloudberry seed oil

Dried press residue of cloudberry [Rubus chamaemorus (Rosaceae)] was extracted with carbon dioxide at pressures of 90-300 bar and at a temperature of 40 or 60 degrees C using a pilot-scale or a production-scale plant. The yield of the extract at the highest pressure was approximately 15% less than that obtained with Soxhlet extraction using diethyl ether as solvent. The extracts were either solids or viscous oils depending on the amount of neutral lipids, which increased with increasing pressure. No significant differences in the composition of the major constituent fatty acids in any of the extracts were found. The color of the extracts was clearly dependent an the amount of carotenes, which consisted mainly of beta-carotene. The content of carotenes in the extracts did not increase at pressures higher than 150 bar. The amount of tocopherols in the extracts obtained at highest pressure was found to be approximately 3 times less than that at lower pressures. Countercurrent CO2 extraction of the cloudberry oil extracted at 300 bar and 40 degrees C resulted in enrichment of tocopherols in the extracts and a decrease in the amount of carotenes. The concentrations of tocopherols and carotenes in all of the CO2 extracts, the countercurrent extracts, and the raffinates were found to be clearly higher than those in the edible part of fresh cloudberry reported by other authors.