Vol. 2, No. 2, Spring 1997
Dr. Angela Fraser
Safe food handling is always important but especially during summer months when outside temperatures can reach over 100 degrees Fahrenheit. At these temperatures, keeping food that should be at 40 degrees Fahrenheit or colder can be very difficult. One food many people forget to keep cold is melons.
Harmful bacteria, particularly Salmonella and Shigella, have been shown to grow on watermelons, cantaloupe and honeydew melons. Some of the largest foodborne outbreaks have been attributed to melons. Three outbreaks of salmonellosis in the 1950s were due to contaminated watermelons. In 1989 to 1990, a large outbreak of salmonellosis in 30 states, affecting approximately 25,000 individuals, was attributed to Salmonella chester. The source of the illness -- imported cantaloupes. Another outbreak in June 1991 affected 15 states and two Canadian provinces and was associated with contaminated cantaloupe from salad bars.
The suspected reason for these outbreaks was that harmful bacteria on the unwashed rind came in contact with the fruit during cutting. When the cut pieces were then held unrefrigerated, the harmful bacteria were able to grow to levels that cause illness. The longer the cut pieces were unrefrigerated, the more the bacteria grew.
Many people mishandle melons because they believe that melons, being fruit, are too acidic for bacteria to grow on them. In fact, because the pH of most melons is higher than 5.0, harmful bacteria can survive and grow on them. Therefore, melons must be handled carefully. Thoroughly wash the surface of all melons with a scrub brush and plenty of water before cutting. Also, use a clean knife and a clean surface when cutting melons. You can minimize the growth of harmful bacteria by keeping cut melon in the refrigerator until ready to serve. Harmful bacteria grow very slowly at refrigeration temperatures. When transporting melons to a picnic, consider cutting up the melon at home, putting the pieces into a closed container and storing the container in a chest full of ice until immediately before serving.
Dr. Angela Fraser, Food Safety Specialist, Family and Consumer Sciences, North Carolina Cooperative Extension Service, North Carolina State University.