By Chelsea Low, CAHNRS and WSU Extension intern
 
PULLMAN – Thanks to WSU food scientist Dong-Hyun Kang and his colleagues, organic produce consumers soon may be able to enjoy their fruits and veggies with less risk of food-borne illness.
 
Results of their study are forthcoming in the International Journal of Food Microbiology.
 
For the past nine months, researchers in the School of Food Science have tested methods to reduce E. coli 0157:H7, salmonella and Listeria monocytogenes on organic fresh lettuce. They achieved their goal by submerging the produce in an ultrasound tank containing minimized amounts of malic, lactic and citric acids.
 
The combined treatment of ultrasound and organic acids has potential for other types of produce as well, Kang said. However, the research showed that some fruits and vegetables, such as tomatoes and strawberries, have skins that are too sensitive to withstand the treatment.
 
Despite some limits on its range of use, Kang believes this approach is a feasible way for processors in the food industry to sanitize most types of fresh produce.
 
“Even local growers could adopt this technology today if they wanted to. It is that simple and straightforward,” he said. “We developed a simple method because, if a procedure like this was difficult at all, no one would use it.”
 
Not only is this method easy to use, it also has the potential to save the organic food industry a lot of money. According to Kang and his fellow researchers, organic acid treatments alone are effective but expensive. Adding ultrasound allowed the team to reduce the quantity of organic acids needed in the solution from 2 percent to .5 percent.
 
The next step will be to conduct the combined treatment on a larger scale to determine the process conditions needed for organic food industrial applications.