Food Lipids: Chemistry, Nutrition, and Biotechnology

Figure 9 Ester interchange reaction between two triacylglycerols, trilinolein and tricaproin,
in the enzymatic production of structured lipids.
Solvent type. The type of organic solvent employed can dramatically affect the
reaction kinetics and catalytic efficiency of an enzyme. Therefore, the choice of
solvent to be used in biocatalysis is critical. Two factors affecting this choice are the
extent to which the solvent affects the activity or stability of the enzyme, and the
effect of the solvent on the equilibrium position of the desired reaction (71). The
equilibrium position in an organic phase is usually different from that in water because
of differential solution of the reactants. For example, hydrolytic equilibrium
is usually shifted in favor of the synthetic product because the product is less polar
than the starting materials (71). The nature of the solvent can also cause inhibition
or inactivation of enzymes by directly interacting with the enzyme. Here the solvent
Figure 10 Ester interchange reaction in the production of structured lipids containing
eicosapentaenoic acid (EPA) with tricaprin and EPA ethyl ester as substrates. An immobilized
Candida antarctica lipase, SP 435, was the biocatalyst. Note EPA esterified to the sn-2
position.
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