When you take that fresh watermelon home, don’t put it immediately in the fridge. Unlike most produce, watermelons do not deteriorate after being harvested. You can benefit from storing them at room temperature, until an hour or two before serving.
The red color of watermelons comes from lycopene, the valuable antioxidant relative of carotene. Scientists at the USDA lab in Lane, Oklahoma discovered that watermelons held for two weeks at room temperature continue to produce lycopene and deepen in color, ending up with 10 to 40% more pigment than freshly harvested melons. On the other hand, watermelons stored in cold temperatures lose lycopene, and develop areas where cells are damaged and leaky. This may be a result of the fruit’s origins, namely hot and dry regions of Africa, and therefore don’t do well in cold conditions.