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Food Lipids: Chemistry, Nutrition, and Biotechnology

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Table 8 Specificity of Triacylglycerol Lipases from Different Sources<br />

Source of lipase<br />

Fatty acid<br />

specificity a<br />

Positional<br />

specificity<br />

Micoorganisms<br />

Aspergillus niger S, M, L sn-1,3 >> sn-2<br />

C<strong>and</strong>ida antarctica S>M,L sn-3<br />

C<strong>and</strong>ida rugosa (syn. C. cylindracea) S, L > M sn-1,2,3<br />

Chromobacterium viscosum S, M, L sn-1,2,3<br />

Rhizomucor miehei S>M,L sn-1,3 >> sn-2<br />

Penicillium roquefortii<br />

Pseudomonas aeruginosa<br />

S,M>>L sn-1,3<br />

b<br />

S, M, L sn-1<br />

Pseudomonas fluorescens S, L > M sn-1,2,3<br />

Rhizopus delemar S, M, L sn-1,2,3<br />

Rhizopus oryzae M, L > S sn-1,3 >> sn-2<br />

Plants<br />

Rapeseed (Brassica napus) c<br />

Papaya (Carica papaya) latex d<br />

Animal tissues<br />

Porcine pancreatic<br />

Rabbit gastric b<br />

a<br />

S, short chain; M, medium chain; L, long chain.<br />

b<br />

Data from Ref. 100.<br />

c<br />

Data from Ref. 101.<br />

d<br />

Data from Ref. 102.<br />

Source Adapted from Ref. 99.<br />

S>M,L sn-1,3 > sn-2<br />

sn-3<br />

S>M,L<br />

S, M, L<br />

sn-1,3<br />

sn-3<br />

action of hydrolysis, i.e., esterification (Fig. 14), or in interesterification <strong>and</strong> transesterification<br />

reactions (Fig. 15). The above properties of triacylglycerol lipases permit<br />

their use as biocatalyst for the preparation of specific lipid products of definite<br />

composition <strong>and</strong> structure that often cannot be obtained by reactions carried out using<br />

chemical catalysts (95). This section outlines some current commercial applications<br />

<strong>and</strong> potentially interesting uses of lipase-catalyzed reactions for the production specialty<br />

products from oils <strong>and</strong> fats.<br />

1. Structured Triacylglycerols<br />

a. Cocoa Butter Substitutes. Some typical applications of lipase-catalyzed interesterification<br />

reactions include the preparation, from inexpensive starting materials,<br />

of products resembling cocoa butter in their triacylglycerol structure <strong>and</strong> physical<br />

properties. Commercial processes for the preparation of cocoa butter substitutes involve<br />

interesterification of palm oil midfraction with stearic acid or ethyl stearate<br />

using sn-1,3-specific lipases, as shown in Fig. 16 (97,104–108).<br />

b. Human Milk Fat Replacers. The triacylglycerols of human milk contain the<br />

palmitic acid esterified predominantly at the sn-2 position. Structured triacylglycerols<br />

resembling triacylglycerols of human milk are produced by transesterification of<br />

tripalmitin, derived from palm oil, with oleic acid or polyunsaturated fatty acids,<br />

obtained from plant oils, using sn-1,3-specific lipases as biocatalyst as outlined in<br />

Fig. 17 (108,109). Such triacylglycerols are used in infant food formulations.<br />

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

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