Nanoscale food protection

Consumption of food contaminated with pathogenic microorganisms or their toxins leads to a host of diseases resulting in serious economic and public health consequences. Some 48 million people in the US annually succumb to foodborne diseases with the hospitalization of 128,000 and death to 3000 people. Pathogenic microorganisms can contaminate fruits and vegetables during the passage through their extensive production chain from field production, intermediate handling, distribution, to food industry, and home utilization. Current disinfection techniques include: chlorine/hypochlorite, chlorine dioxide, peracetic acid, hydrogen peroxide, quaternary ammonium salts, ozone, and UV irradiation. A new technology exhibits inactivation of microorganisms on fresh produce, and food production surfaces to be controlled by water nanostructures generated by electrospraying water vapor. The intervention method utilizes engineered water nanostructures (EWNS) formed in an electrospray with unique properties as a diameter of 25 nm, involving reactive oxygen species, a strong surface charge of 10e/structure, and can be airborne for hours indoors. The electrospray module consisted of an electrostatic precipitator commonly used to aerosolize particles and functionally designed to deliver EWNS to surfaces. The new technology’s efficacy for inactivating representative foodborne bacteria like Escherichia coli, Salmonella enterica, and Listeria innocua on stainless steel surfaces and on organic tomatoes was evaluated. A 1.4 log reduction for E. coli on organic tomato surfaces was found using the EWNS technology for an aerosol concentration of 50,000 cfu/cm at 90 min of exposure compared with control using the EWNS (same temperature and relative humidity). For L. innocua, the dose–response relationship was demonstrated. On surfaces, bacterial concentrations were reduced depending on the microorganism and surface type. The inventors of this technology look for this novel, chemical-free, and environmentally friendly intervention method to offer potential for development and application in the food industry, as a ‘‘green’’ alternative to existing disinfection methods. Environ. Sci. Technol., 2015, 49 (6), pp. 3737–3745.