A slice of cold watermelon can be refreshing on a hot summer day, but a recent study indicates that to get a real nutritional boost, the melon should probably be stored at room temperature until it is cut open for eating. According to a study just published in the Journal of Agriculture and Food Chemistry, storing whole watermelon at room temperature may increase the nutritional value of the melon by as much as 40 percent, compared to melon stored at 55 degrees or in the refrigerator.
Red-fleshed watermelon is recommended by doctors as a healthy food choice similar to tomatoes because it has a substantial amount of carotenoids, especially lycopene – a red carotenoid pigment that has strong antioxidant properties. Lycopene has been shown to protect against cardiovascular disease and some cancers, including prostate cancer; it also protects against UV light damage, and improves bone mineral density and sperm motility.
Because the lycopene content and quality of watermelons is known to vary, scientists at a US Department of Agriculture laboratory in Oklahoma conducted a study to determine the effects of temperature on quality and lycopene content of watermelons. First, they gathered three types of watermelon from local producers on the same day and held them overnight at the same temperature, just under 70 degrees Fahrenheit, and humidity level. The next day 20 of each type were cut open and tested to get a base comparison for each type. Then 20 of each type were stored for 14 days at 41 degrees Fahrenheit (refrigerator temperature), 55 degrees and 70 degrees (room temperature). At the end of the storage period, each melon was cut open and checked for flesh color, composition and carotenoid content.
The melons held at room temperature had a decrease in rind thickness but otherwise showed an increase in red color and carotenoid content, compared to the melons opened right after harvest. The lycopene content increased at least 11 percent and as much as 40% in two types of melon. The melons stored at 55 degrees showed little change compared to the freshly harvested fruit, and those stored at 41 degrees showed a decrease in color and carotenoid content. These results thus indicate that melons stored at room temperature actually gain nutritional value after harvest.
In a post-study interview, a co-author of the study nevertheless cautioned that once a melon has been cut open, it should be eaten right away or stored at a cold temperature to avoid spoilage. She also said that fruit sold in supermarkets is often already fully ripened; therefore, melons probably reach their optimal nutritional value within three to four days of purchase when stored at room temperature.
This information is provided by the Medical Society of the State of New York. For more health-related information and referrals to physicians in your community, contact your local county medical society.
Red-fleshed watermelon is recommended by doctors as a healthy food choice similar to tomatoes because it has a substantial amount of carotenoids, especially lycopene – a red carotenoid pigment that has strong antioxidant properties. Lycopene has been shown to protect against cardiovascular disease and some cancers, including prostate cancer; it also protects against UV light damage, and improves bone mineral density and sperm motility.
Because the lycopene content and quality of watermelons is known to vary, scientists at a US Department of Agriculture laboratory in Oklahoma conducted a study to determine the effects of temperature on quality and lycopene content of watermelons. First, they gathered three types of watermelon from local producers on the same day and held them overnight at the same temperature, just under 70 degrees Fahrenheit, and humidity level. The next day 20 of each type were cut open and tested to get a base comparison for each type. Then 20 of each type were stored for 14 days at 41 degrees Fahrenheit (refrigerator temperature), 55 degrees and 70 degrees (room temperature). At the end of the storage period, each melon was cut open and checked for flesh color, composition and carotenoid content.
The melons held at room temperature had a decrease in rind thickness but otherwise showed an increase in red color and carotenoid content, compared to the melons opened right after harvest. The lycopene content increased at least 11 percent and as much as 40% in two types of melon. The melons stored at 55 degrees showed little change compared to the freshly harvested fruit, and those stored at 41 degrees showed a decrease in color and carotenoid content. These results thus indicate that melons stored at room temperature actually gain nutritional value after harvest.
In a post-study interview, a co-author of the study nevertheless cautioned that once a melon has been cut open, it should be eaten right away or stored at a cold temperature to avoid spoilage. She also said that fruit sold in supermarkets is often already fully ripened; therefore, melons probably reach their optimal nutritional value within three to four days of purchase when stored at room temperature.
This information is provided by the Medical Society of the State of New York. For more health-related information and referrals to physicians in your community, contact your local county medical society.
