Recently, Dr. John Lapuma, author of the American book "The Kitchen Doctor's Big Reference," proposed the following viewpoint: watermelon is best kept at room temperature because the lycopene and beta-carotene content in the watermelon at this time are 40% and 139% higher than in chilled watermelon. These nutritional elements are components of antioxidants that have anti-cancer properties.
On the surface, putting watermelon in the refrigerator is to keep it fresh, but this will actually cause the watermelon to "age" prematurely. Refrigerators contain anaerobic bacteria, and over time, the number of these bacteria will increase, attaching to the cut watermelon flesh. This not only destroys the vitamins, minerals, and other nutrients in the watermelon, but the cold flesh may also cause gastrointestinal disorders, diarrhea, and other symptoms in people with good gastrointestinal function. Furthermore, watermelon is a fruit with high water content, and prolonged refrigeration will cause a large amount of water to evaporate, taking away its nutrients.
Therefore, it is recommended that people buy only as much as they plan to eat. The fresher summer fruits and vegetables are, the better their nutritional value and the fewer side effects they have on the human body. A newly purchased watermelon should not be kept in the refrigerator for more than one day, and once cut, it should not be stored for more than an hour. The ideal temperature is 15°C.