Food Lipids: Chemistry, Nutrition, and Biotechnology

Figure 2 Synthetic scheme for olestra by transesterification and processing.
(105–130�C). Reaction times of 2–6 hours and pressure of 0–5 mm Hg
are required to achieve greater than 95% yield of SPE (14). This is a simple
ester–ester interchange reaction (Fig. 3). The methyl acetate formed is
trapped with a liquid nitrogen (�196�C).
Synthesis based on Na metal (potentially explosive and flammable compound)
as catalyst and sucrose octaacetate and FAME as substrates may not be suitable for
industrial adaptation. Therefore, use of milder catalysts such as sodium methoxide,
potassium soap, and potassium carbonate are encouraged. Shieh et al. (23) recently
reported the optimized synthesis of SPE using potassium hydroxide (KOH) in methanol
plus FAME to form soap (potassium soap) followed by the addition of potassium
carbonate. The reaction time at 144�C was 11.5 hours.
The triacylglycerol for the synthesis can come from vegetable oils and fats,
alone or in combination. The type of product desired dictates the type of fatty acids
needed for synthesis to achieve desired functionality. In most cases, the fatty acid
profiles of finished products will resemble those of the triacylglycerol source (22).
It should be noted that the reactions above are random processes and therefore the
specific position and type of fatty acid on the sucrose molecule will vary from
product to product.
2. Analyses of Olestra (SPE)
No matter what synthetic approach is used, at the end of the reaction, the vessel is
cooled down to approximately 50�C or less and the product neutralized with acid,
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