Watermelons: A renewable energy source?

U.S. scientists say they've discovered watermelon juice can be a valuable source of biofuel

, with the juice from rejected watermelons fermented into ethanol.

U.S. Department of Agriculture research chemist Wayne Fish and a team of scientists at the USDA's South Central Agricultural Research Laboratory in Lane, Okla., evaluated the biofuel potential of juice from 'cull' watermelons -- those not sold due to cosmetic imperfections. Such melons are currently plowed back into the field.

"About 20 percent of each annual watermelon crop is left in the field because of surface blemishes or because they are misshapen," said Fish. "We've shown that the juice of these melons is a source of readily fermentable sugars, representing a heretofore untapped feedstock for ethanol biofuel production".

The study is reported in the journal Biotechnology for Biofuels.