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4: Lipid Oxidation in Irradiated Foods)
Fat is an important component in determining the sensory attributes of foods. It contributes to mouthfeel, aromatic, and textural properties in the foods we consumed. Ironically, over consumption of fat is associated with a number of diseases; namely, hypertension, atherosclerosis, breast and colon cancer, and the development of obesity. It is recommended that "only 30% of energy should come from fat and 10% from saturated fat in Canadian diet". Consumers are demanding low-fat and even no-fat products with sensory qualities similar to those of the regular products. As a result, a number of fat substitutes have been developed. Some of them have been discussed in the section Starch Based Fat Substitutes. In the following section, two other fat replacers will be discussed in greater details: Olestra and Simplesse.Fat Substitutes
Olestra
Olestra is
a trade name for sucrose polyester manufactured by Proctor & Gamble.
This substance is composed of sucrose
(table sugar) with six to eight fatty acids bound to it. These fatty acids
are from vegetable oils such as soybean or corn oil. Since the Olestra
molecule is large in comparison to a triacylglyeride, it is not hydrolyzed
by the digestive enzymes and therefore is not absorbed. As a result,
it passes through the digestive system unchanged and provides zero
calories to the human body. One drawback of the consumption
of Olestra is that it causes a decreased adsorption
of fat-soluble vitamins. It has also been reported that
the consumption of olestra may lead to diarrhea.
Physical and chemical properties of olestra are very similar to fat and are determined by the chain length and saturation of the fatty acids. The color, taste, heat stability, and shelf-life of oil made with Olestra is comparable to those of conventional fats. In addition, Olsetra is heat stable and can be used for cooking, baking, and deep-fat frying.
A Food Additive Petition filed in April 1987 is currently being reviewed by the FDA for the approval of the use of Olestra as shortening. Olestra has been extensively tested to determine its safety.
Simplesse
Simplesse was first introduced by The NutraSweet Company in 1988.
It is made with egg white and/or milk or whey proteins through a process
called microparticulation.
During microparticulation, proteins in solution are deaerated and hearted
to a temperature just below the coagulation point of the proteins.
The solution will then be homogenized and sheared at elevated temperatures.
As a result, the proteins aggregate into small, round particles range in
size from 0.1 to 2.0 um.
The protein aggregates are so small that the mouth cannot perceive them individually. Instead, they roll over one another, creating a creamy taste and texture just like fat. Once ingested, Simplesse is digested and absorbed by the body as protein. However, due to its high water content, each gram of Simplesse yields only 1 to 2 kcal.
Simplesse can be used in a variety of food applications. It can be added
to dairy products such as ice cream, yogurt, cheese sour cream, dips, and
oil-based foods such as salad dressings and mayonnaise. However, the compound
cannot be used to cook foods because heat causes the protein to gel and
lose its creamy quality. The FDA approved the use of Simplesse in frozen
desserts in February of 1990. The resulting product is nutritionally improved
compared to a 16 percent butterfat ice cream, yet it has the taste and
texture of high-fat ice cream.