WASHINGTON--Researchers from the U.S. Department of Agriculture (USDA) South Central Agricultural Research Laboratory in Lane, Okla., reported watermelon has more active carotenoids when stored at room temperature than when significantly chilled.
In its study (J Ag Food Chem, Epub July, 2006), the team tested several popular varieties of watermelon, which is rich in lycopene, stored for two weeks at 70°F, 55°F and 41°F. They found watermelons stored at 70?F, typical room temperature, had substantially more nutrients. In fact, compared to freshly picked fruit, the room temperature watermelons gained up to 40-percent more lycopene and 50-percent to 139-percent more beta-carotene. They concluded watermelons continue to produce nutrients after they are picked, and chilling slows this process.
"All the watermelons used in our study were selected by commercial growers as full ripe when harvested," they reported. "The usual shelf life for watermelons is 14 to 21 days at 55°F after harvest." They added at refrigerated temperatures (41°F), watermelon starts to decay and develop lesions after a week.