SAN DIEGO, April 2 - Those amber waves of grain could turn up in your local fast-food restaurant before long in the guise of "clamshells" - the foldout containers that hold burgers and other sandwiches. Researchers with the U.S. Department of Agriculture have used wheat to make sandwich containers that are more environmentally friendly than the old polystyrene clamshells and keep food warmer than the cardboard containers now in vogue.
The findings, which could be a boon for wheat farmers as well as consumers, were presented today in San Diego at the 221st national meeting of the American Chemical Society, the world's largest scientific society.
Several years ago, many fast-food chains switched to cardboard food containers in response to environmental concerns that polystyrene clamshells did not easily degrade in landfills and contained CFCs (chlorofluorocarbons), which damage the Earth's delicate ozone layer. But there are trade-offs, according to chemist Geoffrey Nobes who reported on the study. Cardboard is "more expensive, heavier and more complicated to make," he says. "And it doesn't keep it [food] as warm."
Nobes is with the USDA's Agricultural Research Service, Western Regional Research Center, in Albany, Calif. He and other researchers there are testing biodegradable clamshells made from wheat - specifically, fiber from the wheat stalk (straw) and starch from the wheat kernels. "The resulting products [containers] are starch-based foam composites with mechanical and thermal properties rivaling those of polystyrene," the researchers report.
"Our starch-based containers are biodegradable," Nobes pointed out. "In fact, if people have a compost [pile] in the backyard, they could throw these containers in the compost."
Biodegradable food containers made with starch aren't a new idea. They are "already being used in the U.S. by a manufacturer of potato starch-based clamshells," Nobes said. "B
Contact: Charmayne Marsh
American Chemical Society