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Food Lipids: Chemistry, Nutrition, and Biotechnology

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Table 6 Advantages of Enzymatic Approach to Structured Lipid Design<br />

Position-specific SL (i.e., desirable fatty acids can be incorporated at specific positions of<br />

triacylglycerol).<br />

Enzymes exhibit regioselectivity (discriminate based on bond to be cleaved),<br />

enantioselectivity (optical activity), chemoselectivity (based on functional group), <strong>and</strong><br />

fatty acid chain length specificity.<br />

Can design SL on case-by-case basis to target specific food or therapeutic use—custom<br />

synthesis.<br />

Products with defined structure can be produced.<br />

Novel products not possible by conventional plant breeding <strong>and</strong> genetic engineering can be<br />

obtained (e.g., by inserting specific fatty acid at the sn-2 position of glycerol molecule).<br />

Mild reaction conditions.<br />

Few or no unwanted side reactions or products.<br />

Can control the overall process.<br />

Ease of product recovery.<br />

Add value to fats <strong>and</strong> oils.<br />

Improve functionality <strong>and</strong> properties of fats.<br />

4. Analysis of Structured <strong>Lipids</strong><br />

Figure 11 presents a purification <strong>and</strong> analysis scheme for enzymatically produced<br />

SLs. Method of analysis depends on whether the SL is synthesized by acidolysis or<br />

by interesterification reaction. The crude SL product can be analyzed with silica gel<br />

G or argentation AgNO3 (based on unsaturation), thin-layer chromatography (TLC),<br />

gas-liquid chromatography (GLC) of the fatty acid methyl or ethyl esters for fatty<br />

acid profile, <strong>and</strong> by reversed phase high-performance liquid chromatography (RP-<br />

HPLC) of molecular species based on equivalent carbon number (ECN) or total<br />

carbon number (TCN). A typical HPLC chromatogram of SL products is shown in<br />

Figure 12.<br />

Other methods of typical lipid analysis described in this book can be applied<br />

to studies of structured lipids. The choice of fractionation or purification technique<br />

depends on substrate or reactant types, products formed, overall cost, <strong>and</strong> whether a<br />

small-scale or large-scale synthesis was employed. The need for improved methodologies<br />

for the analysis of SCFA <strong>and</strong> MCFA components of SLs is emphasized here<br />

because of their volatility during extraction <strong>and</strong> GLC analysis.<br />

Table 7 Potential <strong>Food</strong> Uses of Structured <strong>Lipids</strong><br />

Margarine, butter, spreads, shortening, dressings, dips, <strong>and</strong> sauces<br />

Improve melting properties of fats<br />

Cocoa butter substitute<br />

Confectioneries<br />

Soft c<strong>and</strong>ies<br />

As reduced- or low-calorie fats (e.g., Caprenin, Benefat)<br />

Baking chips, baked goods<br />

Snack foods<br />

Dairy products<br />

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

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