Chlorine dioxide gas mediated inactivation of the biofilm cells of.

This study evaluated the chlorine dioxide (ClO2) gas mediated inactivation of the biofilm cells of foodborne pathogens on food contact surfaces. Biofilm cells of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes were developed on stainless steel (SS) and high density polyethylene (HDPE) coupon surfaces, and 5-day-old biofilms were treated with ClO2 gas at 60 and 90% relative humidity (RH) for up to 20 min. With an increase in gas concentration and treatment time, significant differences (p < 0.05) were observed between reduction levels under different RH conditions. Treatment with 50 ppmv of ClO2 gas (60% RH) for 20 min resulted in log reductions from 2.08 to 4.62 and 2.08 to 4.41 of the biofilm cells of three pathogens on SS and HDPE surfaces, respectively. The levels of biofilm cells of E. coli O157:H7, S. Typhimurium, and L. monocytogenes on SS and HDPE surfaces were reduced to below the detection limit (0.48 log CFU/cm2) within 15, 20, and 20 min, respectively, when exposure to 50 ppmv of ClO2 gas at 90% RH.