Better Fat Substitutes
by Jane M. Sanders
Brace yourself, because the next three terms don't usually go
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
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
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
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 firstname.lastname@example.org.
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