Nanotechnology to the Rescue: Using Engineered Water Nanostructures (EWNS) to inactivate Foodborne Microorganisms

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The burden of foodborne diseases worldwide is huge, with serious economic and public health consequences. The U.S. Department of Agriculture’s (USDA’s) Economic Research Service reported in 2014 that foodborne illnesses are costing the economy more than $15.6 billion and about 53,245 Americans visit the hospital annually due to foodborne illnesses. The food industry is in search of effective intervention methods that can be applied form “farm to fork” to ensure the safety of the food chain and be consumer and environment friendly at the same time.

Researchers at the Center for Nanotechnology and Nanotoxicology of the Harvard T. Chan School of Public Health are currently exploring the effectiveness of a nanotechnology based, chemical free, intervention method for the inactivation of foodborne and spoilage microorganisms on fresh produce and on food production surfaces. This method utilizes Engineered Water Nanostructures (EWNS) generated by electrospraying of water. EWNS possess unique properties; they are 25 nm in diameter, remain airborne in indoor conditions for hours, contain Reactive Oxygen Species (ROS), have very strong surface charge (on average 10e/structure) and have the ability to interact and inactivate pathogens by destroying their membrane.

In a study funded by the USDA and just published this week in the premier Environmental Science and Technology journal, the efficacy of these tiny water nanodroplets, in inactivating representative foodborne pathogens such as Escherichia coli, Salmonella enterica and Listeria innocua, on stainless steel surfaces and on tomatoes, was assessed showing significant log reductions in inactivation of select food pathogens. These promising results could open up the gateway for further exploration into the dynamics of this method in the battle against foodborne disease. More importantly this novel, chemical-free, cost effective and environmentally friendly intervention method holds great potential for development and application in the food industry, as a ‘green’ alternative to existing inactivation methods.

Dr. Philip Demokritou, Associate professor at Department of Environmental Health and lead author of the study mentioned, “Nanotechnology can bring on the table new useful intervention approaches that can be used in the battle against food borne diseases. Using water in its engineered nanoscale form can be a ‘game changer’, cost effective approach that can be easily deployed at various intervention points across the ‘farm to fork’ line”.

Drs. Georgios Pyrgiotakis and Pallavi Vedantam, post-doctoral research fellows in the Department of Environmental Health who are currently further exploring the prospects of this novel high throughput system believe that this technology could not only significantly decrease the microbial load on the fresh produce but also extend shelf life of produce and reduce the number of cases of foodborne illnesses on consumption. The Center for Disease Control (CDC) has estimated 48 million such cases each year in the United States alone, which include 3,000 deaths. Hence, this method could potentially landscape the preventable public health challenge of foodborne infections and craft best ways forward. Prof. Mitchell and his team at SEAS also collaborated in this study.

EST publication can be accessed here. For more information on nano related research at Harvard T.H. Chan School of Public Health please visit our website at