29F-11 |
Antimicrobial effectiveness of chlorine dioxide against foodborne pathogens on cardboard surfaces |
E. CEYLAN, Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS 66506 and J. L. Marsden. Chlorine dioxide has been used as an antimicrobial agent in sanitizers and disinfectants. The objective of this study was to examine the antimicrobial effectiveness of chlorine dioxide at 500 ppm against foodborne pathogens on cardboard surfaces. Five strains of Escherichia coli O157:H7 and Salmonella spp. were grown in Brain Hearth Infusion broth at 37°C for 24 hr. Equal amounts of E. coli O157:H7 strains and Salmonella spp. were mixed to prepare the cocktail cultures. The sterilized cardboard samples (7x7 cm2) were inoculated with the cocktail of E. coli O157:H7 or Salmonella spp., and kept at 8°C for 30 min for bacterial attachment. An inoculation chamber was first sprayed at a rate of 0.12 l/m3 with a 500 ppm chlorine dioxide solution for 15 min. The cardboard samples were placed in the center of the container and sprayed with the 500 ppm chlorine dioxide solution for 30 min to establish a mist of 500 ppm chlorine dioxide. The cardboard samples were kept in the container for another 30 min. A 5x5 cm2 piece was excised from the cardboard samples for microbiological analysis. The number of E. coli O157:H7 and Salmonella spp. was determined using MacConkey Sorbitol Agar and XLD Agar, respectively. The agar plates were incubated at 37°C for 24 hr. The initial inoculum level was 5.7 log cfu/cm2 for both pathogens. The number of E. coli O157:H7 strains and Salmonella spp. was reduced below detection level after 500 ppm chlorine dioxide treatment. The results indicated that the use of 500 ppm chlorine dioxide might induce a 5 log cfu/cm2 or higher reduction of bacterial contamination on cardboard surfaces.
Session 29F, Food Microbiology: Control of foodborne microorganisms by antimicrobials
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