Effect of water on canola oil hydrolysis in an online extraction-reaction system using supercritical CO2

The presence of optimal levels of water in enzymatic hydrolysis reactions in a supercritical CO2 (SCCO2) medium is critical not only as a reactant but also in order to maintain the catalytic activity of the enzyme. The effects of the water flow rate (0.002-0.050 mL/min), the amounts of canola flake (3.0 and 15.0 g) and enzyme (1.0 and 5.0 g of immobilized lipase from Mucor miehei, Lipozyme IM) loads, and the reaction cell size were studied in the continuous enzymatic hydrolysis of canola oil in SCCO2 at 24 MPa and 35 degreesC using an online extraction-reaction system. Supercritical fluid chromatography was used to analyze the product mixtures for their free fatty acid (FFA) and mono-, di-, and triglyceride contents. At the water flow rate of 0.002 mL/min, 97% triglyceride conversion was achieved, i.e., almost a complete hydrolysis. High levels of FFA in the product were obtained with 3 g of canola load, using a smaller reaction cell, and 5 g of enzyme load, indicating a greater extent of hydrolysis.