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Food Lipids: Chemistry, Nutrition, and Biotechnology

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7. Supercritical fluid chromatography (SFC) of trimethylsilyl ether derivatives<br />

of olestra for separation <strong>and</strong> determination of degree of esterification<br />

(28).<br />

8. Spectrophotometry for analysis of olestra content in foods (29).<br />

9. Polarimetry measurements for degree of esterification (30).<br />

10. Desorption mass spectrometry (MS) for characterization of olestra (31).<br />

11. Hyphenated chromatography techniques, such as HPLC-FTIR, GC-MS,<br />

<strong>and</strong> HPLC-GC-FTIR, may also be useful.<br />

Figure 4 shows the result of HPLC separation of olestra or sucrose polyester <strong>and</strong><br />

triacylglycerol blend on a gel permeation chromatography column (32).<br />

C. Olestra-Type Fat Substitutes<br />

1. Sorbitol Polyester<br />

Sorbitol or glucitol is a sugar alcohol (polyol) made by hydrogenation or electrolytic<br />

reduction of glucose. Other polyols like xylitol, mannitol, <strong>and</strong> lactitol can equally<br />

be used for the synthesis of fat substitutes. Up to six hydroxyl groups can be esterified<br />

with fatty acids to produce a nondigestible sorbitol polyester. The structure is<br />

shown in Figure 5. Sorbitol polyester can be synthesized by interesterification of<br />

sorbitol hexaacetate with FAME in the absence of organic solvent (13) or by transesterification<br />

reaction between sorbitol <strong>and</strong> FAME as described above.<br />

Figure 4 HPLC chromatographic analysis of a mixture of olestra <strong>and</strong> triacylglycerol blend<br />

on four gel permeation chromatography columns arranged in series: a, olestra; b, a triacylglycerol;<br />

injection volume, 200 �L; flow rate, 1.0 mL/min; a light-scattering mass detector<br />

was used. (From Ref. 32.)<br />

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

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