Lipase-catalyzed hydrolysis of canola oil in supercritical carbon dioxide

The effect of pressure, temperature, and CO2 flow rate on the extent of conversion and the product composition in the enzyme-catalyzed hydrolysis of canola oil in supercritical carbon dioxide (SCCO2) was investigated using lipase from Mucor miehei immobilized on macroporous anionic resin (Lipozyme IM). Reactions were carried out in a continuous flow reactor at 10, 24, and 38 MPa and 35 and 55 °C. Supercritical fluid chromatography was used to analyze the reaction products. A conversion of 63-67% (triglyceride disappearance) was obtained at 24-38 MPa. Mono- and diglyceride production was minimum at 10 MPa and 35 °C. Monoglyceride production was favored at 24 MPa. The amount of product obtained was higher at 24-38 MPa due to enhanced solubility in SCCO2. Complete hydrolysis of oil should be possible by increasing the enzyme load and/or decreasing the quantity of the oil substrate. There was a drop in triglyceride conversion over a 24-h reaction time at 38 MPa and 55 °C, which may be an indication of loss of enzyme activity. Pressure, temperature, and CO2 flow rate are important parameters to be optimized in the enzyme-catalyzed hydrolysis of canola oil in SCCO2 to maximize its conversion to high-value products.