A University of Maine researcher has received a $4.9-million grant from the U.S. Department of Agriculture and the National Institute of Food and Agriculture to develop ways of using non-thermal technologies to control microbial contamination of low-moisture foods.

Dr. Vivian Wu, a professor of food science, will be lead researcher on a five-year project to explore new technologies to better control microbial contamination of low-moisture foods, such as cereals, nuts and spices, without using heat. “Heat is a very effective way to control microbial contamination, but there are food products that heat just doesn’t work that well,” she said, mentioning such foods as produce and grains. “We want to develop nonthermal processing techniques to eliminate, to maintain the safety of produce and low-moisture food.” USDA has been emphasizing produce safety for years, Wu said, and low-moisture foods are becoming an increasing concern when it comes to food safety and bacterial contamination. To sanitize low-moisture foods, she will be examining the use of cold plasma (ionized atmospheric air), gaseous antimicrobial treatment, and multicolored decontaminating lights. Wu will receive $900,000 of the $4.9 million for her first year of the five-year interdisciplinary project, which will be a joint research collaboration between the University of Maine and USDA’s Agricultural Research Service Eastern Regional Research Center, Virginia Tech, University of Delaware and Ohio State University. Her research approach on the project will be waterless. Through using less water, Wu believes that industrial processors can save money, which would also save consumers money at the retail level. Plus, using less water would be particularly important in drought-stricken agricultural states such as California. “We are hoping that we will be able to develop an integrated system that can eventually be utilized by the industry, can be commercialized, can be truly applied on an industrial scale to control microorganisms,” Wu said. “All of this is waterless … we want to target energy-saving issues.”