PROCESS PARAMETERS INFLUENCING ETHANOLYSIS OF COD-LIVER OIL IN SUPERCRITICAL CARBON-DIOXIDE

Production of ethyl esters from ethanol and cod liver oil by an immobi lized :lipase (E.C. 3.1.1.3), Candida antarctica, in supercritical car bon dioxide is described. The effects of process parameters, such as d ensity of the reaction/extraction medium, flow rate of the carbon diox ide, and ethanol substrate, were investigated. Further, the possibilit y of separating nutritionally valuable fatty acid ethyl esters during the process was evaluated. The results revealed that a high flow rate of ethanol influenced the purity of the product rather than promoting the enzyme reaction. Increasing the carbon dioxide flow rate did not s trongly affect the extraction rate of ethyl esters, which suggests tha t internal diffusion/enzyme kinetics limit the efficiency of the proce ss investigated. Additionally, the first fractions of the extracts obt ained were enriched in short saturated fatty acid ethyl esters, wherea s the last fractions contained a higher proportion of long unsaturated fatty acid ethyl esters. (C) 1998 Elsevier Science B.V.