lipase preparation, as well as efficiency of downstream processing for the separation
of the desired products from the reaction mixture, i.e., fatty acids from acylglycerols
in the case of hydrolysis and alkyl (ethyl, propyl or butyl) esters from acylglycerols
in the case of transesterification with alkyl esters orn-butanol. Acylglycerols and
acetylacylglycerols could be useful byproducts of such processes.
Selective hydrolysis of high-erucic rapeseed oil, catalyzed by lipases fromG.
candidumresults in the enrichment of erucic acid in diacylglycerols to an extent
of 85 % (McNeill and Sonnet, 1995). When hydrolysis, catalyzed byC. rugosali-
pase, is carried out below 20 8 C, the reaction mixture solidifies and the diacylgly-
cerols formed contain as much as 95 % erucic acid (McNeill and Sonnet, 1995).
2.2.5 Enrichment of other fatty acids
Lipase-catalyzed reactions have been employed for the enrichment of several com-
mon and unusual fatty acids via kinetic resolution. For example, oleic acid has been
incorporated into a few selected plant oils by interesterification of the triacylglycer-
ols with methyl oleate, catalyzed byR. mieheilipase (Sridhar et al., 1991). By this
process oleoyl moieties replace the saturated acyl moieties and linoleoyl moieties of
the triacylglycerols, yielding an oil with improved stability and nutritional proper-
ties.
Interesterification (glycerolysis) of animal fats such as beef tallow and lard with
glycerol, catalyzed byPseudomonas fluorescenslipase, results in monoacylglycerols
enriched with saturated acyl moieties in high (45–70 %) yields, when the reaction is
carried out at or below a ‘critical’ temperature of 40 8 C (McNeill et al., 1992). Si-
milarly, lipase-catalyzed glycerolysis of low-erucic rapeseed oil or soybean oil at
58 C, results in monoacylglycerols enriched with palmitoyl and stearoyl moieties
(McNeill et al., 1992). Short-chain fatty acids with desirable flavor have been pro-
duced by selective hydrolysis of butter fat fraction, catalyzed byPenicillium roque-
fortilipase (Lencki et al., 1998).
38 2 Fractionation of Fatty Acids and Other Lipids Using Lipases
Figure 6. Scheme of kinetic resolution for the enrichment of erucic (ERUC) acid via lipase-catalyzed
regioselective transesterification (alcoholysis) of triacylglycerols withn-butanol.