Inactivation methods for human coronavirus 229E on various food-contact surfaces and foods.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of the COVID-19 outbreaks, is transmitted by respiratory droplets and has become a life-threatening viral pandemic worldwide. The aim of this study was to evaluate the effects of different chemical (chlorine dioxide [ClO2] and peroxyacetic acid [PAA]) and physical (ultraviolet [UV]-C irradiation) inactivation methods on various food-contact surfaces (stainless steel [SS] and polypropylene [PP]) and foods (lettuce, chicken breast, and salmon) contaminated with human coronavirus 229E (HCoV-229E). Treatments with the maximum concentration of ClO2 (500 ppm) and PAA (200 ppm) for 5 min achieved >99.9% inactivation on SS and PP. At 200 ppm ClO2 for 1 min on lettuce, chicken breast, and salmon, the HCoV-229E titers were 1.19, 3.54, and 3.97 log10 TCID50/mL, respectively. Exposure (5 min) to 80 ppm PAA achieved 1.68 log10 reduction on lettuce, and 2.03 and 1.43 log10 reductions on chicken breast and salmon, respectively, treated with 1500 ppm PAA. In the carrier tests, HCoV-229E titers on food-contact surfaces were significantly decreased (p < 0.05) with increased doses of UV-C (0-60 mJ/cm2) and not detected at the maximum UV-C dose (Detection limit: 1.0 log10 TCID50/coupon). The UV-C dose of 900 mJ/cm2 proved more effective on chicken breast (>2 log10 reduction) than on lettuce and salmon (>1 log10 reduction). However, there were no quality changes (p > 0.05) in food samples after inactivation treatments except the maximum PAA concentration (5 min) and the UV-C dose (1800 mJ/cm2).