A Sweet Idea: Converting Watermelon Juice into Ethanol

Sweet, refreshing, succulent watermelons: they are perhaps the best known icon of summer. Sure, the fruit's rosy flesh is a delicious treat. But watermelons can be more than that. Researchers the US Department of Agriculture's Agricultural Research Service (ARS) found that that the simple sugars in watermelon juice can be made into ethanol.

Normally, ethanol is sourced from crops such as corn, sugarcane and sugar beet. But Wayne Fish and his ARS colleagues believe that their work on watermelon will play an important role in the push to diversify the country's biofuel crop portfolio. In 2007 alone, more than 80 million pounds of watermelon, that's 20 percent of the US's total harvest, were left in fields because they were not suitable for the market. The researchers hope to give these watermelons a new lease on life.

Fish and colleagues showed that ethanol can be fermented from the glucose, fructose and sucrose in watermelon juice. On the average, 20-pound watermelon will yield about seven-tenths of a pound of ethanol. The ARS scientists are still fine-tuning their approach, focusing on ways to extract all the possible sugars. The approach also complements on going studies to commercially extract lycopene and citrulline, nutraceutical compounds thought to promote health benefits, from watermelon juice.

Read the full article at http://www.ars.usda.gov/is/pr/2009/090520.htm