This isn't a new item but something that I hadn't heard anything on in some time. A while back I ran across an article talking about using waste watermelons as a feedstock for ethanol production.
"Historically, our industry will abandon 20-25 percent of the crop that they grow every year," said Bob Morrissey, executive director of the National Watermelon Association. "After they go through the field three to five times and pick the ripe watermelons that are ready, they'll have a bunch of melons left, but they'll be spread all over in every direction. It's not economically feasible to send any labor in there to walk 10 yards in this direction and get a watermelon, walk 15 yards in that direction for another two or three - then drag the truck up the dirt road and get a few more," said Morrissey.
Besides those left in the field, watermelons that aren't visually perfect are rejected. That adds up to a lot of melons that never make it to the Fourth of July picnic.
Several months ago, Morrissey was discussing new marketing possibilities with a watermelon researcher, when an idea hit them like a ton of bricks. Why not create a new revenue stream for those 800 million pounds of watermelons abandoned every year? Why not turn the melons into fuel?
And the reason they think they would do good as a feedstock for making ethanol is because watermelons contain 10-14% sugar that can be fermented into ethanol.
That article is from September 2006 and I really hadn't heard anything else about it until I ran across some information at the USDA website.
The USDA Agriculture Research Service began a research project in August 2007 to determine the suitability of using watermelon juice, rind and pulp waste streams for making ethanol.
The objectives of this project are (1) to experimentally optimize the conditions for fermentation of watermelon juice to fuel ethanol, and (2) to optimize the process and conditions for conversion of the complex carbohydrates of watermelon pulp and rind to their constituent sugars for subsequent fermentation.
If this proves successful it could open the door to using other waste fruits for ethanol production as well. This could provide ethanol producers with a low cost feedstock and also provide fruit producers with added revenue for something that at the moment has no value.