Production of structured triacylglycerols in an immobilised lipase packed-bed reactor: batch mode operation
✍ Scribed by PA González Moreno; A Robles Medina; F Camacho Rubio; B Camacho Páez; L Esteban Cerdán; E Molina Grima
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2004
- Tongue
- English
- Weight
- 167 KB
- Volume
- 80
- Category
- Article
- ISSN
- 0268-2575
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✦ Synopsis
Abstract
Structured triacylglycerols with caprylic acid at the sn‐1 and sn‐3 positions of the glycerol backbone and eicosapentaenoic acid (EPA) at the position sn‐2 were synthesised by acidolysis of a commercially available EPA‐rich oil (EPAX4510, Pronova Biocare) and caprylic acid catalysed by the 1,3‐specific immobilised lipase Lipozyme IM. The reaction was carried out in an immobilised lipase packed‐bed reactor by recirculating the reaction mixture through the bed. The exchange equilibrium constants between caprylic acid and the native fatty acids of EPAX4510 were determined. The n‐3 polyunsaturated fatty acids (PUFAs), EPA and docosohexaenoic acid (DHA), were the most easily displaced by the caprylic acid. The exchange equilibrium constants were 3.68 and 3.06 for EPA and DHA, respectively. The influence of the flow rate of the reaction mixture through the packed‐bed and the substrate concentration in the reaction rate were studied. For flow rates between 74 and 196 cm^3^ h^−1^ (bed of 6.6 mm internal diameter and 0.46 porosity) and triacylglycerol concentrations between 0.036 and 0.108 M, the data fitted well to an empirical kinetic model which allowed representative values of the apparent kinetic constant to be obtained. Hence, the average reaction rates and kinetic constants of exchange of caprylic acid and native fatty acids of EPAX4510 could be calculated. In the conditions indicated, the parameter (lipase mass × time/triacylglycerol mass, m~L~t/V[TG]~0~) constituted the intensive variable of the process for use in predicting the composition of structured triacylglycerols at different reaction times. At equilibrium, the structured triacylglycerol produced had the following composition: caprylic acid 59.5%, EPA 9.6%, DHA 2.2% and oleic acid 11.8%. Copyright © 2004 Society of Chemical Industry