An interesting study hammers home the point once again eating fruits and vegetables in their most natural state -- raw and often unrefrigerated -- offers the most health benefits. That's exactly what scientists found when they compared key antioxidant levels in whole watermelons stored for two weeks in a refrigerator versus at room temperature.
Although alterations in moisture, light and temperature during the time a watermelon is harvested and shipped to market can cause lycopene levels to vary by as much as 20 percent, scientists know little about how storage methods inside a home affect antioxidant levels. So researchers compared samples from six seedless and seeded watermelons stored in coolers ranging in temperature from 41-70 degrees Fahrenheit.
Compared to when they were picked (and depending on variety), the carotenoid levels of watermelon samples stored at normal room temperatures rose by as much as 40 percent after two weeks. Additionally, watermelons stored at room temperatures had thinner rinds and their flesh was generally darker than when picked (another indication of the lycopene boost).
Conversely, watermelons stored in colder temperatures showed a drop in carotenoid enzyme activity, a sign the ripening process that builds up beneficial antioxidants stalls.
That said, small chunks of watermelon stuffed into popsicle molds and frozen for a couple of hours make for a cool, refreshing summertime treat to beat the heat.
Journal of Agriculture and Food Chemistry July 7, 2006
Yahoo News July 31, 2006