Lipase‐catalyzed alcoholysis with supercritical carbon dioxide extraction 1: Influence of flow rate

Abstract

A combined process of lipase (E.C. 3.1.1.3) catalysis and extraction of product with supercritical carbon dioxide was studied. The effect of different flow rates of the extraction fluid on the selective removal of the ethyl esters (EE) synthesized in a lipase-catalyzed alcoholysis of cod liver oil with ethanol was investigated. The faster the flow rate, the faster the extraction rate and the higher the recovery of EE. For example, after a 270-min extraction, the total recovery of EE was 1520 mg for a flow rate of 0.3 liter carbon dioxide at atmospheric pressure and room temperature/min (NL/min) as compared to 250 mg when 0.015 NL/min was used. The concentration of EE in the carbon dioxide was found to decrease with increasing flow rate, which indicates that the rate of diffusion of EE limits their extraction at fast flow rates. A high flow rate was found to result in a more selective extraction of EE, i.e., less amounts of other lipid components present in the reaction mixture were coextracted with the EE. Further, by increasing the flow rate, the equilibrium of the reaction was shifted slightly toward ester synthesis. An increase in the flow rate from 0.015 to 0.075 NL/min resulted in an approximately 10% increase in total conversion (from 73 to 82%), whereas only a negligible increase was obtained when the flow rate was increased further to 0.15 NL/min. FIG. 3. Effect of flow rate on the concentration of EE in carbon dioxide. Symbols and abbreviation as in Figure 2.

Lipase‐catalyzed alcoholysis with supercritical carbon dioxide extraction 2: Phase behavior

“…]11 c,;. )hCll.IS]o~], lhese resLltis show [hzl| iil the actual iipasecatalyzed alcohoiysis experiments (19,20) which were canted out at 9 to 24 MPa and 40~ the reaction system comprises lhrec i~hases, i.e.. vapor-liquid-solid: the solid phase is here lhc immobiIization support containing the e.!zylne. Furlhermore, this vapor-liqt_lid-.,~{flid system probably prevails during the entire reaclion.…”

“…lipids, and SC-CO 2 present at the beginning of :m actual enzyme reaction experiment. The experimental apparatus and the reaction conditions used for tile lipase-catalyzed aIcoholysis of cod liver oil have been described (20),…”

“…(Reykjavik, Iceland). Lipid residues were obtained after lipase-catalyzed ethanolysis of cod Iiver oi[ in SC-CO 2 (20). Dimodan LS.…”

“…for example, been reported that a stable microemulsion is formed when fish oiI/MG/water or glycerol are mi• in the proportions of 77:20:3 (2 I1, In an extractive reaction process, the formation of a micmemulsion during the alcoholysis reaction would result not only in quite different conditions for the enzyme reaction but also hi the entrainment of the reactants with the outgoing CO 2 flow and. consequently, much less selective extraction of products, Tile objective of this work was to investigate the phase behavior of the reaction system by simulating the conditions used in our earlier work on extractive reaction (19,20),…”

Acylglycerol synthesis including EPA and DHA from rainbow trout (Oncorhynchus mykiss) belly flap oil and caprylic acid catalyzed by Thermomyces lanuginosus lipase under supercritical carbon dioxide

“…SCCO2 is a markedly attractive process solvent for enzymatic catalysis as it offers even more advantages over organic solvents, e.g., it is nonflammable, nontoxic, and inexpensive. It is considered a Generally Recognized as Safe (GRAS) compound and has revealed a variable density, great solvent power [16]. Combining the advantages of supercritical fluid (SCF) and CO2, several studies have employed SCCO2 as a medium for enzymatic catalyzed reactions on oxidation, hydrolysis, transesterification, esterification and enantioselective synthesis [17].…”