A new source of ethanol, sweet potatoes, could reduce the biofuel industry's controversial use of corn, researchers said Nov. 29. North Carolina State University scientists said they were making progress in developing a tuber with a high starch content that may produce more ethanol per weight than corn.
"These are not your grandmother's sweet potatoes," said Craig Yencho, a horticulturalist at the university heading a project to develop alternative uses for the vegetable. "The industrial sweet potato is edible, but not palatable."
Yencho said that while the table version is orange inside, the industrial sweet potato typically has a purple or white skin and white flesh with a much higher starch content that limits its sweet taste.
The researchers said a challenge is lowering production costs to take advantage of the high starch content of sweet potatoes, which traditionally are planted by hand. "But if we could plant them the same way you plant an Irish potato -- by planting cut 'seed' pieces and mechanically planting them into the ground, we could cut planting costs in half," Yencho said.
"The ethanol production from sweet potatoes then becomes much more cost-effective and feasible. Not only would these sweet potatoes be a much more viable ethanol source than corn, but because they are industrial sweet potatoes, we wouldn't be taking away from a food source." Ethanol, produced from corn in the U.S. and sugar cane in Brazil, can be used in place of petroleum for some fuels. But high demand for ethanol has led to a jump in corn and other food prices, creating other problems.
Yencho is currently in China helping the world's leading producer of sweet potatoes tap the crop's biofuel potential.
Copyright Agence France-Presse, 2007