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Food Lipids: Chemistry, Nutrition, and Biotechnology

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Figure 28 Preparation of fatty acids <strong>and</strong> glycerol by lipase-catalyzed hydrolysis of fats.<br />

labile high-�-linolenic acid–containing perilla oil (238). More recently, enzymatic<br />

‘‘presplitting’’ of oils prior to steam splitting is being considered as an economically<br />

feasible alternative to complete enzymatic hydrolysis or steam splitting alone (247).<br />

a. Fatty Acid Concentrates. Triacylglycerol lipases from various organisms have<br />

one common feature in their selectivity toward groups of fatty acids/acyl moieties<br />

having olefinic bonds at definite positions (249) or geometric configuration (249).<br />

Thus, several lipases from microorganisms, plants <strong>and</strong> animal tissues discriminate<br />

against fatty acids/acyl moieties having a cis-4, cis-6, or a cis-8 double bond as<br />

substrates in hydrolysis, esterification, <strong>and</strong> interesterification reactions, as summarized<br />

in Table 9.<br />

Data presented in Fig. 29 show for example the substrate specificity in esterification<br />

of a wide variety of fatty acids with n-butanol using the latex from papaya<br />

plant (Carica papaya) as biocatalyst (256). In these studies a mixture of the fatty<br />

acid examined <strong>and</strong> the reference st<strong>and</strong>ard, myristic acid, at equal molar concentrations<br />

in n-hexane was reacted with n-butanol using the above biocatalyst <strong>and</strong> the<br />

course of formation of butyl esters under competitive conditions was followed. The<br />

competitive factor � was determined according to Rangheard et al. (252) from the<br />

concentrations of the two substrates (Ac1X <strong>and</strong> Ac2X) at time X by the equation:<br />

� =(VAc1X/KAc1X)/(VAc2X/KAc2X)<br />

where V is maximal velocity <strong>and</strong> K is the Michaelis constant. The competitive factor<br />

Table 9 Specificity of Triacylglycerol Lipases from Different Sources Toward Various<br />

Fatty Acids/Acyl Moieties<br />

Source of lipase Discrimination against a<br />

Microorganisms<br />

C<strong>and</strong>ida rugosa (syn. C. cylindracea)<br />

Penicillium cyclopium<br />

Penicillium sp. (lipase G)<br />

Rhizomucor miehei<br />

Rhizopus arrhizus<br />

all-cis-4,7,10,13,16,19-DHA, petroselinic<br />

(cis-6-octadecenoic) acid, GLA (all-cis-<br />

6,9,12-octadecadienoic) acid, stearidonic<br />

(all-cis-6,9,12,15-octadecatetraenoic) acid,<br />

dihomo-�-linolenic (all-cis-6,9,12eicosatrienoic)<br />

acid<br />

Plants<br />

Rape (Brassica napus) seedlings DHA, petroselinic, GLA, stearidonic, <strong>and</strong><br />

Ref.<br />

250–252<br />

253–255<br />

dihomo-�-linolenic acids<br />

Papaya (Carica papaya) latex<br />

Animal tissues<br />

256<br />

Porcine pancreas DHA, petroselinic acid, GLA, <strong>and</strong><br />

stearidonic acid<br />

250<br />

a DHA, docosahexaenoic acid; GLA, �-linolenic acid.<br />

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

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