A Penn State professor is currently developing nonthermal ways to kill food pathogens that cause E. coli O157:H7, Salmonella and other serious outbreaks that come from contaminated food.

Ali Demirci, associate professor of agriculture and bioengineering, found new ways to rid some foods of their harmful microorganisms.

Pathogens are microorganisms that grow in food and can potentially make people sick. They are in the air, and our bodies naturally resist them, but when consumed, they are concentrated in the body, Roy Young, head of the agriculture and bioengineering department, said.

"They go into our digestive system and produce toxic compounds that make us sick," Demirci said.

Usually, to kill pathogens, food is cooked before it is served.

"Remember your mom's kitchen," Demirci said. "She would usually cook the meat to kill the microorganisms, so they are killed before we eat them."

Demirci said he is trying to find nonthermal ways to kill pathogens in food because processors cannot use heat to sell rare meat, and people do not always cook their vegetables.

"Using nonthermal [methods] kills the microorganisms and doesn't change the quality of the food, especially with fruits and vegetables," Demirci said.

Demirci said some methods that are being researched are the use of ozone gas technology, electrolyzed oxidizing (EO) water and ultraviolet (UV) light.

Ozone, UV rays and two different types of EO solutions kill the microorganisms, Demirci said.

"One EO solution is like the bleach solution your mom would make to disinfect the kitchen," he said. " The other is a soapy solution."

Both solutions are water-based and are meant to clean and disinfect the food to which they are applied, he added.

Chemical methods have been used in the past to kill pathogens, but the chemical residue then needs to be removed or the taste of the food can be distorted, Young said.

Young added that nonthermal means leave chemicals out of the equation, eliminating this problem, but just rinsing food in water is not sufficient.

"Just washing your food can get rid of some pathogens, but not nearly enough," Young said.

There is not one method that works best. All methods are efficient nonthermal processes. Certain applications for each process may be good for one type of food, but research is being done to find the best process for each individual food, Demirci said.

Consumers benefit the most from the discovery of these nonthermal processes, both Demirci and Young said.

"There will be food that is safe to eat and doesn't make us sick," Demirci said.

Restaurants, grocery stores and other places that are sources for food will also benefit, but helping the consumer is the bottom line, Young said.

"The consumer benefits the most because we all eat food," Young said. "I don't know anyone that can live without food."

The byproducts of microorganisms can be beneficial. Some can be used as medicines and, therefore, Demirci's finding would also help the medical field, Young said.

"Byproducts of microorganisms work 24/7 and don't demand minimum wage," Young said. "If we can use them for good, we will attack pathogens naturally and then the medical chain would benefit, too."