In Pennsylvania, Agricultural Research Service scientists demonstrated that a relatively inexpensive steam cleaner designed to remove wallpaper and clean outdoor grills can rid cantaloupes of E. coli, Salmonella, and Listeria more effectively than existing washes and chlorine treatments. Pathogen levels on the surfaces of the steam-treated melons were generally 1,000 times lower than those on untreated melons and pathogens on cut-up pieces of the cantaloupes were reduced beyond detection.
The ARS study involved submerging cantaloupes in a bath inoculated with E. coli, Salmonella and Listeria strains. After drying and refrigeration, the cantaloupes were cleaned with a commercially available power steamer. The technique produced sufficient heat to kill surface pathogens but not enough heat to damage the fruits.
Processors and distributors could apply steam when cantaloupes are put into washers or as they are moved on conveyor belts during processing. The technique also may sanitize watermelons, honeydews, cucumbers and baby carrots.