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Pasteurizing fruit? It could help fight salmonella

The idea of pasteurizing fruit sounds odd, but Agriculture Department researchers say a form of the technology might help fight outbreaks of salmonella that scientists are increasingly tracing back to fresh fruits and vegetables.

Bassam Annous, a microbiologist at the Agriculture Department’s food safety technologies research unit in Wyndmoor, Pennsylvania, said his experiments have shown dramatic reductions in levels of salmonella infections on cantaloupes that have been pasteurized. He said the process wouldn’t work with leafy vegetables or apples because it causes lettuce to wilt and apples to turn brown, but he said there’s no reason it couldn’t be used for citrus fruits, avocados and perhaps tomatoes.

The process involves immersing the fruits in water heated to 169 degrees Fahrenheit for three minutes then sealing each fruit in a plastic bag to prevent re-contamination before rapidly cooling the produce in ice water.

Annous said colonies of salmonella often aren’t affected by chlorine rinses and other sanitation measures processors use because the bacteria cling to the rind and form a protective biofilm around them. Pathogens left on the rind of fruits and vegetables are transferred to the flesh of the produce during cutting or processing.