Dr. Ruan in lab.

MN Impact: New process reduces contamination in powdered foods

May 29, 2020


Increasing occurrences of foodborne pathogens in dry powdered foods have become a major concern to food industries and consumers. In particular, strains of Salmonella spp. are responsible for over one million illnesses, 19,000 hospitalizations and 380 deaths in the U.S. annually. 

What has been done

U of M researchers have developed a novel method for pasteurization of food using intense pulsed light and low temperature microwave technology, along with a photocatalyst and a microwave absorbent that decontaminates granular or powdered food and food ingredients. 


Researchers have shown this process reduces the microbial count in wheat kernels by over 3-5 logs in less than 15-30 seconds while maintaining under 40-60°C temperature during processing with minimal food quality changes. The process directly applies to powdered foods, grains, and nuts (i.e. wheat flour, non-fat dry milk, spices, wheat kernels, sunflower seeds, almonds, hazelnuts, etc.) and researchers have tested its effectiveness by inactivating a variety of microbial contaminants (such as C. sakazakii, E. faecium, B. cereus) commonly found in food.

Implementation of this platform, which could be added easily into existing conveyor belt systems, will cost-effectively improve the safety of powdered foods, and thus enhance the competitiveness of the U.S. food industry and increase the consumption of U.S. agricultural products. In addition, the new technology will reduce the risk of foodborne outbreaks associated with the consumption of powdered foods, which will have a significant impact on the health and living standard of consumers.