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Food Lipids: Chemistry, Nutrition, and Biotechnology

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lipases include ion exchange resins (DEAE-Sephadex A50 or Amberlite IRA94)<br />

(137) <strong>and</strong> others (134), adsorbants such as silica gel (143), microporous polypropylene<br />

(133), <strong>and</strong> nylon (148). In other cases, lipases have been immobilized by<br />

entrapping them in gels of photo-cross-linkable resins (ENT <strong>and</strong> ENTP) (135). Immobilization<br />

using methods described in the references cited above does not involve<br />

chemical modification of the enzyme. More recently, Braun et al. (141) achieved<br />

immobilization of C. rugosa lipase on nylon by covalent attachment to the support<br />

after conversion of carbohydrate groups on the enzyme to dialdehydes.<br />

VI. INDUSTRIAL APPLICATIONS<br />

A. General Uses<br />

The current industrial enzyme market is about $600 million, with lipases representing<br />

about 4% of the worldwide market. The three major industrial enzyme companies<br />

worldwide are Novo Nordisk (>50%), Genencor (35%), <strong>and</strong> Solvay. Lipases are<br />

currently used, or have the potential for use, in a wide range of applications: in the<br />

dairy industry for cheese flavor enhancement, acceleration of cheese ripening, <strong>and</strong><br />

lipolysis of butterfat <strong>and</strong> cream; in the oleochemical industry for hydrolysis, glycerolysis,<br />

<strong>and</strong> alcoholysis of fats <strong>and</strong> oils; <strong>and</strong> for the synthesis of structured triglycerides,<br />

surfactants, ingredients of personal care products, pharmaceuticals, agrochemicals,<br />

<strong>and</strong> polymers (149,150).<br />

The Colgate–Emery process, currently used in the steam fat-splitting of triacylglycerols,<br />

requires 240–260�C <strong>and</strong> 700 psi, has energy costs, <strong>and</strong> results in an<br />

impure product requiring redistillation to remove impurities <strong>and</strong> degradation products.<br />

Also, this process is not suitable for highly unsaturated triacylglycerols (150).<br />

Lipase-catalyzed reactions offer several benefits over chemical reactions, including<br />

stereospecificity, milder reaction conditions (room temperature, atmospheric pressure),<br />

cleaner products, <strong>and</strong> reduced waste materials (44,151,152).<br />

The largest current use of industrial enzymes is in laundry detergents, where<br />

they combine environmental friendliness <strong>and</strong> biodegradability with a low energy<br />

requirement <strong>and</strong> efficiency at low concentrations. The current U.S. market share of<br />

enzymatic laundry detergents is approaching 80%, <strong>and</strong> the U.S. detergent enzyme<br />

market is about $140 million. Essentially four types of enzyme are used in detergents:<br />

proteases, amylases, lipases, <strong>and</strong> cellulases. These enzymes perform multiple functions<br />

(e.g., stain removal, antiredeposition, whiteness/brightness retention, <strong>and</strong> fabric<br />

softening). Proteases were the first <strong>and</strong> are the most widely used enzymes in detergent<br />

formulations. Lipases are relatively new introductions to detergents, where they attack<br />

oily <strong>and</strong> greasy soils <strong>and</strong> contribute to making the detergents particularly effective<br />

at lower wash temperatures. However, a current limitation is that most lipases<br />

are unstable in alkaline conditions in the presence of anionic surfactants used in<br />

laundry detergents (19). However, some lipases may be relatively resistant to certain<br />

surfactants (153).<br />

B. New Lipases/Modification of Known Lipases<br />

Early studies with fungal lipases focused on the isolation <strong>and</strong> characterization of<br />

extracellular lipases from various species. Some of the thoroughly studied fungal<br />

lipases include those from C. (cylindracea) rugosa, R. miehei, P. camembertii, H.<br />

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

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