Food Lipids: Chemistry, Nutrition, and Biotechnology

onds as fast as ester bonds. Examples include diether monoesters of glycerol,
triglyceryl ethers, and trialkoxyglyceryl ether (TGE).
5. Apply chemistry unrelated to triacylglycerol structure. A good example is
the use of polymeric materials having physical and functional properties
similar to those of conventional fats and oils such as phenylmethylsiloxane
(PS) or silicone oil and paraffins.
6. Evaluate naturally occurring substances as potential low-calorie fat substitutes.
Jojoba oil is an excellent example.
7. Use enzymes to synthesize reduced-calorie fat substitutes. Examples include
sugar mono- and diesters, glycerophospholipids, mono- and diacylglycerols,
and structured lipids.
8. Introduce oxypropylene group between glycerol and fatty acids to form
propoxylated molecules. An example is esterified propoxylated glycerol
(EPG).
B. Olestra or Sucrose Polyester: Brief History of Development
Sucrose fatty acid polyester (SPE) development dates back to the year 1880, when
a derivative of sucrose was prepared by acetylation to produce sucrose octaacetate
(i.e., sucrose containing eight acetate groups). Following this, other carbohydrate
acetates were successfully prepared. In 1921 Hess and Messner (21) synthesized
sucrose octapalmitate (sucrose esterified with eight molecules of palmitic acid, a long
chain fatty acid) and sucrose octastearate. In 1952 the concept of sucrose polyester
production was initiated when the president of the Sugar Research Foundation, Henry
B. Hass, asked Foster D. Snell to look into the possibility of ‘‘hanging a fat tail on
sucrose’’ for use in detergents. The idea was that since sucrose is highly hydrophilic,
a lipophilic tail on sucrose would result in a molecule that is amphiphilic (both water
and oil loving), hence able to serve as an excellent surfactant. It was anticipated that
production would be easy and the product biodegradable under aerobic and anaerobic
conditions. It turned out that the chemical synthesis was not that easy without the
use of solvents like dimethylformamide (DMF), dimethylsulfoxide (DMS), and dimethylpyrolidone
(DMP) to solubilize sucrose and free fatty acids. This process,
called the Hass-Snell process, was applicable only to the synthesis of sucrose monoand
diesters, otherwise called sucrose fatty acid esters (SFEs). These are digestible
and good nonionic surfactants, as we shall see later in this chapter. By today’s
standard, the solvents used are not food grade; therefore, products made in them are
unacceptable for human consumption.
The other concept was to find means of reducing fat-derived calories without
resorting to dilution with, say, water, air, carbohydrates, and proteins. The aim was
to somehow come up with a fatlike molecule that would significantly reduce fat
calories by preventing their hydrolysis and absorption. This led to the discovery of
a nondigestible and nonabsorbable fatlike molecule called sucrose fatty acid polyester,
now known as olestra (generic name) or Olean (brand name), by Mattson and
Volpenhein (7) while working on the absorption of fats by infants.
Sucrose is a nonreducing disaccharide and the common table sugar. ‘‘Olestra’’
or ‘‘sucrose polyester’’ refers to sucrose esterified with six to eight fatty acids. SPEs
become undigestible when the number of fatty acids esterified is greater than 4. The
structure of sucrose polyester is given in Figure 1. Procter & Gamble, which was
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