SCIENTISTS TURN CORN INTO PLASTIC PACKAGING

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If you want to use the word ``corny'' to describe the packaging research being done by food scientists at the University of Illinois at Urbana-Champaign, go right ahead. They won't mind at all.

After all, corn is at the center of a recent project that mixed the corn byproduct zein with fatty acids and flax oil to create water-resistant, plasticlike food containers that researchers say have a future in the biodegradable products market.

In a paper published earlier this year, scientists Graciela Wild Padua, Huey-Min Lai and Lun Shin Wei report they were able to turn zein into plasticized resins that can be molded into plates, sandwich containers, sealing material and trays.

Zein, which is extracted from corn-gluten meal used to make ethanol and also from dry milling waste, currently is used only in small amounts as coatings for candies, rice, dried fruits and pharmaceutical tablets. Most zein is used to supplement animal feed.

There is plenty of zein to go around in Illinois, since each of the 1.4 billion bushels of corn the state cranked out last year produced 2 pounds of zein. Illinois trails only Iowa in national corn production.

When untreated zein was used for packaging in the experiment, it was brittle and absorbed too much water to be viable as a commercial product. Mixing zein with fatty acids and flax oil may have solved that problem.

Melting zein with fatty acids, such as palmitic or stearic acid, produced moldable resins that were stronger and more waterproof. This plasticized zein will degrade naturally when disposed of, acting as a slow-release nitrogen source for soil, researchers said.

Padua said the project was fueled by the need for biodegradable products as well as a desire to give the corn market an economic boost.

``Zein was part of the waste stream that was just being destroyed and not used commercially,'' Padua said of the three-year project.

``This product could increase the economic viability of ethanol, which is an important economic interest for the state of Illinois.''

The researchers now are creating zein-based wrapping films with varied flexibility. Their work is funded by the Illinois Council on Food and Agricultural Research and the Illinois Corn Marketing Board.

Philip Shane, the board's marketing development director, said he is optimistic zein resin prices will equal those of petroleum-based resins in two or three years.

Cornstarch already is used to create loose-fill packaging material, and other companies have commercialized cornstarch-based plastic-style resins and resin blends.

``We hope to develop biodegradable packaging and increase the value of a co-product like zein,'' Shane said.

The task of turning the zein resin into a competitive product has fallen to Munir Cheryan, another Urbana-Champaign researcher.

Cheryan's first job will be identifying practical ways to reduce the resin's per-pound cost, which currently exceeds $5.

One such method might be to find a way to reuse the alcohol used to extract zein from corn rather than throwing it away. Cheryan added that the zein resin might benefit costwise if it is not required to meet food-product grades.

Researchers also are working on an agreement between the University of Illinois and a consortium of Illinois-based corn processors to market the zein resin.

Cheryan said the zein resin has attracted some interest from Europe, particularly Germany, where legislation requires manufacturers to collect and recycle their own packaging.

``People have told us they want to buy the product but they don't want to be involved with the process and the alcohol and all that,'' Cheryan said. ``We wouldn't be involved with this unless we saw a market in it.''