Extraction of coriander seed oil by CO2 and propane at super- and subcritical conditions

Oil extraction from coriander seed was studied with carbon dioxide and propane as solvents, under sub- and supercritical conditions. The ratio of solvent to seed (g/g) required to achieve a complete oil extraction was between 20 and 40 using CO2 at pressures of 200 and 300 bar and temperature of 35°C. A complete oil recovery could be attained with propane or propane-rich solvents at 25°C and 50, 80 and 100 bar. The ratio of solvent to seed needed to approach maximum extraction was varied between 1.3 and 2.5. The solvating power of propane and propane-containing solvents was proved to be much higher than that of CO2. The fractions trapped in the initial period of extraction with CO2 were rich in essential oils. It was stated that the content and composition of essential oils in the extracts can be influenced by modifying the solvent composition and changing the extraction conditions, which had negligible effect on the fatty acid composition of the recovered oils. The changes in the tocopherol content of the extracts as a function of supercritical fluid extraction (SFE) conditions are also investigated in the present work.