Description
Olestra is the common name for the mixture of sucrose esters
formed from the addition of six, seven, or eight fatty acids to the
available eight free hydroxyl moieties of sucrose. Saturated and
unsaturated fatty acids of chain length C12 to C20 and higher can
be used to manufacture olestra. The final product is defined by
specifications which include the fatty acid composition. Sucrose
ocataester is the principal component of olestra.
Olestra is proposed for use as a calorie-free replacement for up to
100 percent of the conventional fats and oils used in the preparation
of savory snacks such as flavored and unflavored chips and
crisps, flavored and unflavored extruded snacks, and crackers.
These uses include substitution for fat for frying as well as sources
of fat in dough conditioners, oil sprays, and flavors. Olestra has
been approved for use in savory snacks as a texturizer and as a
formulation aid (21 CFR 170.3(o)) at levels not in excess of that
reasonably required to produce its intended effect.
Olestra is prepared by the addition of medium- and long-chain
fatty acid methyl esters to sucrose in the presence of catalysts. The
post-synthesis purification steps are the same as those generally
depend upon physical separations and do not involve chemical
bond rearrangement or the use of solvents or catalysts. The methyl
esters used to prepare olestra can be obtained by procedures common
in the food industry such as the reaction of refined triglyceride
oils with methanol in the presence of sodium methoxide or from
esterification of their fatty acids. The resulting esters are washed
with water to remove residual methanol, dried under vacuum, and
distilled. The fats and oils can be derived from a variety of edible
sources such as, but not limited to, soybean, palm, coconut, fully
hydrogenated rapeseed, and cottonseed. Sucrose and the methyl
esters are mixed with an alkali metal soap of a long-chain fatty
acid. A small amount of transesterification catalyst such as an
alkali metal (sodium or potassium) carbonate, bicarbonate,
hydride, or alkoxide is added and the mixture heated under vacuum
to withdraw the volatile methanol by-product. Following the reaction,
excess methyl esters and free methanol are removed by evaporation
under vacuum. Standard steam deodorization removes free
fatty acids and odors. Different lots of olestra may be mixed to
achieve desired properties or to meet product specifications.
Uses
Sucrose polyester is a fat replacer manufactured using vegetable oil and sucrose to produce a product that is not absorbed or metabolized, passing undigested through the digestive tract. Fatsoluble vitamins a, d, e, and k can be carried out of the body with . It is noncaloric because it is not hydrolyzed by digestive lipases. Approved for use in savory snack foods; advisory labeling is required. It is used in fat-free chips and crackers.
