09.12.2012 Views

Food Lipids: Chemistry, Nutrition, and Biotechnology

Food Lipids: Chemistry, Nutrition, and Biotechnology

Food Lipids: Chemistry, Nutrition, and Biotechnology

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Scheme 3 Principle of kinetic resolution via lipase-catalyzed hydrolysis.<br />

In a commercial process fish oil is partially hydrolyzed by C<strong>and</strong>ida rugosa<br />

lipase to yield an acylglycerol fraction enriched in 20:5 �3, <strong>and</strong> especially in 22:6<br />

�3; the acylglycerol fraction is subsequently isolated by evaporation <strong>and</strong> converted<br />

to triacylglycerols via hydrolysis <strong>and</strong> reesterification, both catalyzed by R. miehei<br />

lipase (265). Using Rhizopus delemar lipase, selective esterification of tuna oil fatty<br />

acids with lauryl alcohol, extraction of the unreacted fatty acids <strong>and</strong> their repeated<br />

esterification with lauryl alcohol has resulted in an unesterified fatty acid fraction<br />

containing 91% 22:6 �3 (266). Selective interesterification of tuna oil triacylglycerols<br />

with ethanol using Rhizomucor miehei lipase as biocatalyst yields an acylglycerol<br />

fraction containing 49% 22:6 �3, whereas selective esterification of tuna oil fatty<br />

acids with ethanol yields an unesterified fatty acid fraction containing 74% 22:6 �3<br />

(267).<br />

Fatty acids generated by lipase-catalyzed hydrolysis of a commercial singlecell<br />

oil from Mortierella alpina have been subjected to selective esterification with<br />

lauryl alcohol, catalyzed by lipase from C<strong>and</strong>ida rugosa. This leads to an increase<br />

in the arachidonic acid content from 25% in the starting fatty acid mixture to over<br />

50% in the fatty acids that remained unesterified (268).<br />

Also �-linolenic acid, a constituent of certain seed oils, such as borage oil <strong>and</strong><br />

evening primrose oil, can be prepared as a concentrate together with linoleic acid<br />

by lipase-catalyzed selective hydrolysis (Fig. 31) under mild conditions <strong>and</strong> typical<br />

data obtained with lipase from C<strong>and</strong>ida rugosa are shown in Fig. 32 (269).<br />

Figure 30 Preparation of concentrates of docosahexaenoic acid (DHA) via lipase-catalyzed<br />

selective hydrolysis of marine oils.<br />

Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!