Supercritical carbon dioxide extraction of high-value substances from soybean oil deodorizer distillate

This work attempted to recover high-value substances such as free fatty acids, tocopherols, sterols, and squalene by investigating a supercritical fluid CO2 (SF CO2) distillation-extraction processing of soybean oil deodorizer distillate. Experimental conditions varied between 50 and 90 degreesC, at 24.1 and 31.0 MPa. Reverse-phase high-performance liquid chromatography analysis was performed to analyze 14 components in the extracts after SF CO2 treatment. Experimental results indicated that when tocopherols were extracted at 31.0 MPa, 90 (top) to 70 (bottom) degreesC, and 1000-L STP CO2 usage, their recovery reached 83.6% and the average value of the concentration factor was 1.38. Furthermore, the concentration factor of tocopherols grew to 1.70 when the extracts collected in the top exceeded 400-L STP CO2. The concentration factors of fatty acids, squalene, and stereols were 1.37, 1.26, and 0.60, respectively. This investigation also found that the percentage of total fatty acids decreased, while polyunsaturated fatty acids increased, with an increase in the CO2 volume given the same extraction condition.