Title: Alternative Sweeteners

536 Deis
ninths of the fat available in salatrim was used by the body, the product would
have a food factor of 5/9—related to both fat and calories.
The ideal fat replacer, or fat substitute, should have a physical appearance,
thermal stability, and melting point close to that of the fat being replaced. The
‘‘synthetic oil’’ approach has been to devise a molecular backbone to which fatty
acids can be attached such that digestion is altered. Olestra is a mixture of hexa-,
hepta-, and octa-fatty acid esters of sucrose (35). As opposed to the glycerol
backbone of triglycerides, olestra has a sucrose backbone, to which six to eight
long fatty acid chains have been added (70% of the molecules have eight long
chains). Olestra is synthesized from sucrose and vegetable oil (cottonseed or soybean),
and it has physical properties comparable to conventional fats used in
savory snacks and crackers. The complexity of the molecule inhibits the activity
of digestive enzymes required to break it down. Therefore, olestra passes through
the body undigested, contributing no fat or calories to foods. Olestra is a thermally
stable, fryable fat substitute that can substitute for all of the oil in a product,
contributing essentially no fat and no calories (36–38). This has been commercialized
in several lines of potato and tortilla chip products.
On January 24, 1996, the FDA approved olestra for use ‘‘in place of fats
and oils in prepackaged ready-to-eat savory (i.e., salty or piquant, but not sweet)
snacks. In such foods, the additive may be used in place of fats and oils for frying
or baking, in dough conditioners, in sprays, in filling ingredients, or in flavors’’
(CPR 172.867c). The product must bear an informational statement that says,
‘‘This product contains olestra. Olestra may cause abdominal cramps and loose
stools. Olestra inhibits the absorption of some vitamins and other nutrients. Vitamins
A, D, E, and K have been added.’’ Olestra’s approval by the FDA did not
come without cost—nearly 30 years, 270 volumes of data, and more than 150
long-term and short-term studies.
The synthetic route to healthy fats is not easy. Other fat substitute projects
have either stalled out or have been placed on hold as the olestra project has
progressed. Pfizer Food Science Group developed a mixture of fatty acid esters
of sorbitol (Sorbestrin), which was reported to be a thermally stable, fryable fat
substitute with a caloric content of 1.5 kcal/g. This product is not available commercially,
and its use would require a full food additive petition in the United
States. Other potential fat substitutes based on the same idea—fatty acid esters
of novel backbones—will face the same scrutiny (and expense), so we cannot
expect any newcomers to this area in the foreseeable future. Projects (Table 6)
reported at ARCO Chemical Company (EPG, or propoxylated glycerol esterified
with fatty acids), Frito-Lay Inc. (DDM, or dialkyl dihexadecylmalonate), and
Best Foods (TATCA, trialkoxycitrate and trioleyltricarballyates) have not received
much press in recent years, but these also would require approval as food
additives. Although successes have been achieved recently in what are termed
‘‘structured fats,’’ these have not come without considerable time and cost. The