Watermelons are not just a favorite summer treat, – according to new research by the US Department of Agriculture, they may soon fuel our cars. Research reveals that watermelon juice has a relatively high concentration of directly fermentable sugars, which may be a valuable source for biofuel due to the ease with which they can be fermented into ethanol. But don’t worry about your favorite corn field being plowed under to make way for a new cash crop – researchers say there are enough wasted watermelons out there to use as biofuel feedstock.
The recent development was revealed by the USDA South Central Agricultural Research Laboratory in Lane, OK, which has been looking to watermelons to determine if their juice was a viable feedstock for biofuels. Not only did they determine it was, but they also determined that enough feedstock could be created from leftover watermelons already being grown. “About 20% of each annual watermelon crop is left in the field because of surface blemishes or because they are misshapen; currently these are lost to growers as a source of revenue.” So farmers could begin to sell their blemished watermelons for biofuels and create a new revenue stream rather then plow them back into the field.
Watermelons are also high in certain nutraceuticals – lycopene and L-citrulline, which are important nutrients for humans. If production of these nutraceuticals from watermelons increased, it would yield a waste stream of watermelon juice at the rate of over 500 L/t of watermelons. Since watermelon juice contains 7 to 10% (w/v) directly fermentable sugars and 15 to 35 umol/ml of free amino acids, it has great potential to produce biofuel.
Lead image by ~Rungue