Comparison of two kinds of pumpkin seed oils obtained by supercritical CO2 extraction

The oils from two kinds of pumpkin seeds, black and white ones, were extracted by supercritical CO₂ (SC‐CO₂). The technological variables for SC‐CO₂ extraction were optimized and the resulting oils were analyzed by GC‐MS. As a result, the optimal conditions for SC‐CO₂ extraction were as follows: 25～30 MPa, 45 °C, SC‐CO₂ flow rate of 30～40 kg/h. The main compounds in the resulting oils were 9,12‐octadecadienoic acid, 9‐octadecenoic acid, stearic acid, palmitic acid for both types of pumpkin seeds, however, the black seed oil contains more unsaturated fatty acids (UFA) than the white seed oil. On the other hand, some compounds including heptadecanoic acid (0.27%), tetracosanic acid (0.1%), 9‐dodecaenoic acid (0.45%) and pentadecenoic acid (0.05%) were found in white seed oil but not in black seed oil; while eicosanic acid (0.05%), 11,14‐eicosadienoic acid (0.2%), 11‐octadecenoic acid (0.06%), 7‐hexadecenoic acid (0.02%) and 1,12‐tridecadiene (0.02%) were only found in black seed oil.