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Fall 1998

Research Magazine > ARCHIVE > Summer 97 > Article

Better Fat Substitutes
by Jane M. Sanders

Brace yourself, because the next three terms don't usually go together:

  • low-calorie
  • nutritional
  • fat

That may seem an unlikely combination, but food scientist Casimir Akoh would like to make the trio commonplace. In his UGA lab, he's achieving something nature hasn't yet been able to accomplish: a low-calorie, nutritional fat that could reduce your cholesterol level, boost your immune system - and still taste good.

"Nature just does not provide the right combination of low-calorie fatty acids in a single glycerol molecule - or at least not in an amount to be considered nutritionally or medically beneficial," said Akoh, an associate professor of food science and technology who holds an adjunct appointment in foods and nutrition.

So Akoh is fashioning a variety of low-calorie fat substitutes, called structured lipids, by exchanging properties of one fatty acid - whether saturated or unsaturated - for those of another.

His current projects include a low-calorie fat substitute he created from medium- and long-chain fatty acids from fish oil. The resulting liquid could be used in salad dressing, intravenous solutions and formula for premature infants, Akoh said.

"Our studies in mice have shown that it reduces cholesterol by 49 percent and boosts the immune system by increasing T-cells 19 percent," he said. "This could be of benefit to AIDS patients who have low T-cell counts."

In developing a fat substitute, Akoh begins by selecting a combination of short-, medium- and long-chain fatty acids. These acids are the primary ingredients in fats, and they are categorized according to the number of carbon atoms strung together in a chain.

For example, Akoh always begins with a long-chain fatty acid, such as those in vegetable oil, because of its essential nutritional value. But then he combines it with a lower-calorie, short- or medium-chain fatty acid that metabolizes faster and provides quick energy.

"The combination of fatty acids is important because the different types deliver their benefits via two different physiological pathways - the long chains through the lymph system and the short and medium chains through the circulatory system," he said.

The end product retains the physical properties of high-calorie, good-tasting, fat-containing foods, but without the health risks. In fact, it actually can reduce cholesterol and boost the immune system. "My goal is to create a structured lipid that is nutritionally and medically beneficial," Akoh said.

Akoh uses enzymes, rather than chemicals, to create structured lipids because "enzymes allow you to put unique fatty acids in specific positions in a triglyceride molecule to form a new structured lipid," he said. "Also, using enzymes, which we all have in our bodies, is more natural. Consumers don't like chemically synthesized products."

Results from his fat substitute research using fish oil, a project funded in part by the International Life Sciences Institute, are scheduled for publication later this year. His next steps now are to determine the benefits of this structured lipid in rats, pigs and ultimately in humans, he said.

Meanwhile, Akoh continues to concoct other low-calorie fat substitutes and study the nutritional benefits of those already on the market, such as the ones in popular snack foods. He also studies zero-calorie fat substitutes, such as Olestra, which he first researched as a graduate student.

"I love the challenge of food biotechnology," said Akoh, who designed UGA's graduate education program on the subject. "I want to do all I can with my brain and, at the same time, improve the quality of life for people. You know, fat is the culprit for a lot of diseases."

For more information, access http://www.uga.edu/~fst/, or e-mail Casimir Akoh at cmscakoh@uga.cc.uga.edu.


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