Enrichment of n-3 PUFA contents on triglycerides of fish oil by lipase-catalyzed trans-esterification under supercritical conditions

• Published in: Biochemical engineering journal Vol. 29; no. 1; pp. 27 - 34
• Main Authors: Lin, Tsao-Jen, Chen, Shin-Wan, Chang, An-Chan
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01.04.2006; Amsterdam Elsevier Science; New York, NY
• Subjects: Biological and medical sciences; Biotechnology; Enzyme technology; Fundamental and applied biological sciences. Psychology; Mucor miehei; n-3 Polyunsaturated fatty acid; Production kinetics; Supercritical fluid; Trans-esterification; n-3 Polyunsaturated fatty acid; Supercritical fluid; Enzyme technology; Trans-esterification; Production kinetics; Enzyme; Polyunsaturated fatty acid; Triacylglycerol lipase; Esterases; Supercritical state; Triglyceride; Fish oil; Esterification; Carboxylic ester hydrolases; Production; Hydrolases; Kinetics
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2005.02.035

The immobilized 1,3-regiospecific lipase, Mucor miehei, was employed to catalyze the trans-esterification reaction to enrich n-3 polyunsaturated fatty acid (n-3 PUFA) content of triglycerides (TG) in Menhaden oil under supercritical carbon dioxide (SCCO 2). A supercritical reacting system with a syringe pump to pressurize CO 2 to supercritical condition and a high-pressure liquid pump to transfer the substrate into the reactor is applied to carry out experiments. Through the saponification of Menhaden oil followed by urea inclusion, 80.1 wt% of n-3 PUFA can be concentrated with containing 29.4 wt% EPA and 41.8 wt% DHA. The profile of conversion shows a constant increase at beginning 5 h, but after which the conversion levels off. Pressure up to 103.4 bars has a significant positive effect on the conversion of n-3 PUFA onto TG. Further increasing pressure, the conversion rate decreases due to the transformation of the spatial structure of lipase and leads to deactivate. The enzyme exhibits a good performance and stability in the region of 323 K. Ethanol is used as a co-solvent and its maximal addition is 10 wt% of the total substrates. The optimal substrate molar ratio of TG to n-3 PUFA is about 1/4 by considering the TG inhibition. The conversion in SCCO 2 appears 40 wt% higher than in n-hexane at ambient pressure after 5 h. The ping-pong bi-bi mechanism was proposed for the kinetic model of the reaction. The final rate equation can be simplified and expressed by a modified Michaelis–Menten equation. Based on the evaluated kinetic constants, there was 7.3% deviation of the total n-3 PUFA content between the experimental and the predicted data.