Researchers have found a new way to kill harmful microbes inside packaged food and beverages at room temperature. The process, which creates ionized gas called plasma inside a sealed package by introducing an electrical current, was shown to inactivate bacteria in less than a minute.
The Purdue University research team, led by food science professor Kevin Keener, found that subjecting the sealed atmospheric gases to an electric field temporarily created molecules of ozone, nitrogen oxides, hydrogen peroxide and others. These compounds kill foodborne bacteria like E. coli and Salmonella and then revert back to atmospheric gases, the scientists say. Their findings were published in the Journal of Applied Microbiology.
"Even in the most resistant bacteria-growing media, 45 seconds of treatment gave us complete elimination of the E. coli,” Keener said in a statement. “Under a microscope, we saw holes forming in the cell walls of the bacteria.”
Creating the electrical field uses about the same energy as a standard lightbulb, and costs would be comparable to existing food and beverage sanitation methods.
They say that their technique might be applied to liquids like fruit juices “to achieve something similar to pasteurization without the heat and quality changes that occur with that process,” Keener said.
Top Image: Purdue University food scientist Kevin Keener is developing methods using cold plasma to kill bacteria in packaged foods. Photo courtesy Purdue/Tom Campbell.