Inactivation of Deposited Bioaerosols on Food Contact Surfaces with UV-C Light Emitting Diode Devices

Abstract

The airborne transmission of infectious diseases and bioaerosol-induced cross-contamination pose significant challenges in the food, dairy, and pharma industries. This study evaluated the effectiveness of 279 nm UV-C LED irradiation for decontaminating bioaerosols, specifically containing microorganisms like E. coli (C3040- Kanamycin resistant), Salmonella Enteritis (ATCC 4931), and Pseudomonas fragi (ATCC 4973), on food contact surfaces. Borosilicate glass, silicon rubber, and stainless steel (316L) surfaces were selected for experimentation for their usage in the food industry. A 50µL cell suspension was aerosolized at 25 psi pressure using a 4-jet BLAM Nebulizer within a customized glass chamber and then deposited onto the surface of the coupons. The serial dilution approach was used for the microbial enumeration, followed by double plating. With a low RMSE and high R2 values, the biphasic kinetic model demonstrated the excellent goodness of fit parameters. At a UV-C dose of 6 mJ cm− 2, glass surfaces showed the maximum microbial inactivation ( i.e. 2.80, 3.81, and 3.56 log CFU/mL for E. coli, Salmonella, and P. fragi, respectively). Stainless steel and silicon rubber showed significant microbial inactivation but were consistently lower than glass. Our research indicates that UV-C LEDs can disinfect bioaerosols on food contact surfaces effectively.