Dike Ukuku and colleagues at the ARS Food Safety and Intervention Technologies Unit demonstrated the method is more effective than existing washes and chlorine treatments.
They submersed 24 cantaloupes in a bath inoculated with E. coli, Salmonella and Listeria strains, then dried and refrigerated them at 41 °F for seven days.
The team used a power steamer to steam-clean the cantaloupes by sweeping the spray nozzle across them for three minutes.
Researchers placed the nozzle three inches from the cantaloupe, a distance that produced 154 °F steam at the point of contact. This was hot enough to kill surface pathogens but not damage the fruit.
Pathogen levels were generally 1,000 times lower on the surfaces of steam-treated melons (99.9% reduction) and were undetectable on cut-up pieces.
Surface pathogen levels were about 100 times lower than when sanitized with chlorine.
Ukuku added processors and distributors could apply steam when cantaloupes are put into washers or as they pass along on conveyor belts during processing.