Watermelon More Nutritious at Room Temperature

02/08/06 If you want to eat watermelon for its nutritious value, you are better off storing it at room temperature than refrigerating it. Levels of beta carotene are double and levels of lypocene are 20% higher, say researchers from the USDA Agricultural Research Service, Lane, Oklahoma, USA.

This new finding has surprised many people who thought refrigeration would conserve essential nutrients. As far as watermelons are concerned, the opposite seems to be the case.

The research was carried out because studies had already indicated what effect moisture, temperature and light may have on harvesting and packaging of the fruit's lycopene content, but nothing was known about what effect temperature may have on storage.

Penelope Perins-Veazie and Julie Colling stored uncut, fully ripe melons at 68 degrees Fahrenheit overnight. The next morning they were cut up and sampled for colour, condition and carotenoid levels. They also stored various samples of different types of melons for two weeks at 70, 55 and 41 degrees Fahrenheit.

The researchers found that melons stored at room temperature experienced an increase in carotenoid levels of 11% to 40%. Those stored at low temperatures saw much lower or no increase in carotenoid levels.

Apart from proving this scientifically, the scientists said you can see some differences with the naked eye. After two weeks the melons that were stored at room temperature were darker than when they were first picked. The darker colour is due to an increase in lycopene content.

The melons stored at room temperature also had thinner rinds than those stored at colder temperatures. This means the ripening process had continued. Those stored at colder temperature had rinds of the same thickness as on the day they were harvested.

The researchers stressed that the benefits of room-temperature storage apply only to uncut watermelons. If you cut one and want to store it you should leave it in the fridge. However, if you want to store an uncut one for a few days, it may be better to leave it at room temperature.

If you have left the watermelon for a few days at room temperature, it is then OK to place it in the fridge to cool it down before you eat it. Cooling it does not reverse the process, it only slows it down or stops it.

Previous studies have also indicated that the nutritional values of bananas and peaches are also enhanced better at room temperature.