[The following is an exact transcript of this podcast.]
There’s a traditional bowl in Korea that locals say makes food safer. And they might be right. The bowl is made of almost 80 percent copper. Copper ions can escape into the food. That’s a good thing, according to a presentation at the Society for General Microbiology's autumn meeting. Korean scientists showed that copper ions can destroy bacteria in raw fish and shellfish.
The researchers were concerned about a specific seafood bacteria called Vibrio. It causes about 12 percent of food poisoning cases in Korea. The scientists placed a brass plate—brass is a copper alloy—at the bottom of a fish tank. Copper ions diffused into the water. The bacteria absorb the copper from the water. They die and fall from fish gills and flesh to the bottom of the tank. They’re even flushed out of fish organs. After almost two days, the copper had destroyed 99.99 percent of the Vibrio bacteria in those living fish and shellfish. The scientists recommend placing a brass plate in all tanks that contain fish destined for consumption – and, of course, that Koreans keep using traditional kitchenware.