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Food Lipids: Chemistry, Nutrition, and Biotechnology

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Figure 3 Synthetic scheme for olestra by interesterification (ester interchange) <strong>and</strong><br />

processing.<br />

washed, bleached, distilled (to remove unreacted substrates <strong>and</strong> sucrose ester with<br />

low degree of esterification), deodorized, <strong>and</strong> analyzed for extent of esterification<br />

(22). Antioxidant(s) may or may not be added to prevent oxidation during storage<br />

(Figs. 2 <strong>and</strong> 3). Olestra can be analyzed by any of the following techniques or<br />

combinations thereof:<br />

1. Thin-layer chromatography (TLC), Iatroscan, <strong>and</strong> TLC-recording densitometry<br />

for degree of esterification (18).<br />

2. Gas–liquid chromatography to determine the fatty acid composition of<br />

the product after transmethylation of olestra (10,18,24) or to determine<br />

olestra content after derivatization (silyl or acetate derivatives).<br />

3. Column chromatography to separate products of small-scale synthesis<br />

(10,14).<br />

4. High-performance liquid chromatography (HPLC) to analyze the content<br />

of olestra in, say, salad dressing, cooking oil, margarine, <strong>and</strong> spreads<br />

whose ingredients include triacylglycerols <strong>and</strong> fat-soluble vitamins, or<br />

analysis by size exclusion chromatography (SEC) for oxidized, polymerized,<br />

or heated olestra (25–27).<br />

5. Fourier transform infrared spectroscopy (FTIR) for functional group <strong>and</strong><br />

hydroxyl value determinations (14,18).<br />

6. Nuclear magnetic resonance (NMR) spectroscopy for structural elucidation<br />

(14,18).<br />

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

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