With names like hydroxypropyl methylcellulose, edible food
coatings may not sound very appetizing. But Manjeet Chinnan’s
research is making them much more appealing.

Lasts Longer, Less Fattening, Tastes
Better

A University of Georgia food science and technology
professor,
Chinnan has shown that edible films keep fruits and vegetables
fresh longer. His research proves they can increase the shelf
life of foods like roasted peanuts by as much as 60 percent.

And for the growing number of Americans fighting the battle
of the bulge, the news is even more appetizing.

In two studies to be published later this year in the
Journal
of Food Science and the Journal of Food
Engineering,
Chinnan’s research team has shown that edible films can reduce
the amount of fat in fried foods.

In tests on fried chicken strips, Chinnan tested a variety
of coatings, all derived from plants. He found that some reduce
fat absorption by more than a third. The coated chicken was
moister,
too.

Other Uses, Too

Chances are good that you’ve already eaten some of the
coating
ingredients Chinnan tests. They’re used to thicken, coat, bind
or gel everything from sausage and salad dressing to ice cream
and beer.

“People in Asia have been using rice and soybean starches
and proteins for centuries,” Chinnan said. “They use
wrappers made from such ingredients to hold the shape of jellied
candies as well as to prevent stickiness.”

But Chinnan isn’t just working with centuries-old films. He’s
developing and characterizing new films and coatings, too, with
further functional properties.

Many of the transparent coatings Chinnan uses in his research
have little or no taste of their own. They don’t interfere with
the flavor of the foods they protect.

And because the coatings usually are made from plants, they
could lead to more environmentally friendly packaging of food
products, Chinnan said.

Meats Are a Challenge

“The biggest challenge has been working with meats,
because
the films are in a (water-based) solution, and it takes time for
them to evaporate,” he said.

“We don’t want to leave the meat at room temperature for
microbial reasons,” he said. “And meats don’t dry as
well when cold.”

So it was a boon when Chinnan’s team discovered that for
frying
meats like chicken, edible coatings work best when mixed with
the
batter instead of being applied beforehand.

For this project, Chinnan leads a team of UGA College of
Agricultural
and Environmental Sciences postdoctoral fellows, graduate
students
and visiting scientists from other nations.

Extends Shelf Life

The team is finding ways to use coatings to keep frying oils
fresher, too. When food is fried, fat and acids in the food or
its marinade — things like vinegar and lemon juice — mix with
the oil, causing it to break down. The edible coatings create
a barrier that keeps the fat and acid out of the oil and extends
the oil’s shelf life.

Chinnan’s group is also testing a peanut-protein coating they
make in their lab. “It’s not very easy to make because of
the nature of protein,” he said.

“Proteins are not easy to handle,” he said.
“They’re
fragile. But maybe by combining them with some other material,
we can increase their stability and enhance their physical
properties.”

The UGA food scientists are working on engineering films with
properties that could deliver other benefits, too. These films
may be able to:

* Transfer flavors to foods.

* Add health-promoting vitamins.

* Reduce surface contamination
of produce.

Future research will be devoted to determining which films
are most cost-effective, Chinnan said.

“We’re trying to optimize films and coatings, not only
the types of films but also the quantity to apply,” he said.
“Ultimately, my goal is to have increased food choices with
added value and safety for consumers.”