The optimum extraction conditions of peanut oil by supercritical carbon dioxide (SC-CO2) were studied by semi-continuous method, and the extracted peanut oil was sent to the National Grain and Oil Quality Supervision and Detection Center for detection. The results showed that the optimum technological conditions for SC-CO2 extraction of peanut oil were as follows: extraction temperature 50 C, extraction pressure 30 MPa and dynamic extraction 120 min. Under these conditions, the oil yield can reach 49%. The results showed that the content of insoluble impurities was less than 0.003.2%, the acid value was less than 12.5 (KOH) mg/g, and the peroxide value was less than 1.6 mmol/kg. No residual solvent was detected. Supercritical extraction of peanut oil has bright color, light yellow and transparent, high oil yield, and important parameters can meet the national first-class oil standards, which proves that supercritical extraction technology is a highly efficient method for extracting high-quality peanut oil.
Key words: supercritical CO2 extraction, peanut oil extraction, semi-continuous extraction, oil quality inspection