Modificación enzimática de aceite de pescado en CO2 supercrítico

Abstract

Fish oil is one of the main sources of omega 3 polyunsaturated fatty acids (n-3 PUFAs). These essential fatty acids are of great interest since they present well established healthy effects. In the last years, a high number of functional foods based on n-3 PUFAs have been developed. These applications require of fish oil concentrates with a high content in n-3 PUFA, high bioavailability and good stability against oxidation. Therefore, the raw material has to be modified in order to obtain fish oil derivatives with these properties. Enzymatic modification of fish oil in supercritical carbon dioxide (SC-CO2) has been proposed as an alternative to conventional methods and the use of organic solvents and other chemicals, high temperatures and intensive manipulation of the raw material, which lead to product degradation. The main advantages of enzymes are their high specificity and catalytic activity at mild conditions. On the other hand, the incorporation of SC-CO2 improves the miscibility of the reactants and enhances the mass transfer rate, thus accelerating the reaction. Moreover, SC-CO2 is considered as a green solvent. It is non-toxic and can be easily separated from the reaction products by simple release of pressure. It also displaces oxygen from the reactor, avoiding oxidation. In the present work, some fundamental studies focused on the understanding and optimization of the global process of production of n-3 PUFA concentrates by enzymatic modification of fish oil in SC-CO2 are described. Among them, the effects of SC-CO2 treatment on the residual activity of several commercial enzymes, the phase behaviour of the reaction system in order to find regions with good miscibility conditions, and th kinetic study of the enzymatic ethanolysis of fish oil in SC-CO2. To conclude, future works focused on the applications of the technology (continuous process, product fractionation and formulation) will be commented.