Investigation of the bactericidal effect of a plasma-activated water (PAW) aerosol as a surface disinfectant

There is a constant demand for innovative technologies that can safely reduce spoilage and pathogenic microorganisms in food without compromising the taste, safety or quality of the product. Aerosols of plasma-activated water (PAW) generated from distilled water may serve as innovative and alternative surface disinfectants in food and veterinary production systems. This study examined the effectiveness of a PAW aerosol-producing device in reducing Escherichia coli dried onto metal discs. These metal discs were placed in a 1 m 3 chamber and sprayed with the PAW aerosol for 15 s or 1 min and from a 50 or 70 cm distance. Metal discs placed in a Petri dish protected from direct spray served as a reference control for the treated metal discs. A total of 31 metal discs were tested in 10 trials, and only 2 demonstrated a significant reduction (>4 log 10 ) of E. coli . Contrary to previous studies, where immersion of food into PAW indicated a potential for disinfection in the food processing industry, the results indicate the limitations of PAW sprayed as an aerosol for disinfection of surfaces. Further studies would be needed to establish the capacity of PAW to disinfect depending on the application and target. • Bactericidal effect of a PAW aerosol device was tested using E. coli on surfaces. • The PAW aerosol device did not consistently reduce E. coli on surfaces. • Further research on the PAW aerosol technology is needed for biocide application.