Cold plasma puts the chill on norovirus

WASHINGTON — A nasty stomach virus that can linger on fruits and veggies may have met its match in cold plasma.

In experiments, the ionized gas, created by filtering room-temperature air through an electric field, virtually eliminated norovirus from lettuce, researchers reported February 7 at the American Society for Microbiology Biothreats meeting.

 Norovirus is the leading cause of foodborne illness in the United States, infecting more than 20 million people every year. Sterilizing food with heat is one way to kill the virus, but that approach doesn’t work for fresh produce. Cold plasma could be a way to sterilize fruits and vegetables without damaging them, said Hamada Aboubakr, a food microbiologist at the University of Minnesota in St. Paul.

Aboubakr and colleagues used a cold plasma device to blast contaminated romaine lettuce leaves and stainless steel surfaces. After five minutes, the plasma wiped out about 99 percent of norovirus particles.

The researchers are testing the device on other foodborne viruses such as hepatitis A, which sickened more than 140 people last year after they ate contaminated strawberries. Unpublished experiments have shown that cold plasma also can destroy drug-resistant bacteria on chicken breasts and leafy greens. Aboubakr hopes to adapt the technology for use in restaurants, on cruise ships and in the produce aisles of grocery stores.