Location: Residue Chemistry and Predictive Microbiology ResearchTitle: Effect of Water Activity on Inactivation of Listeria monocytogenes Using Gaseous Chlorine Dioxide – A Kinetic Analysis
|HYEON-WOO, PARK - Kangwon National University|
|Hwang, Cheng An|
Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/27/2020
Publication Date: 12/2/2020
Citation: Hyeon-Woo, P., Chen, G., Hwang, C., Huang, L. 2020. Effect of water activity on inactivation of listeria monocytogenes using gaseous chlorine dioxide – A kinetic analysis. Food Microbiology. 95:103707. https://doi.org/10.1016/j.fm.2020.103707.
Interpretive Summary: Gaseous chlorine dioxide (ClO2) is a potent disinfectant that can be used to inactivate foodborne pathogens on food surfaces. However, its effectiveness may be affected by water activity. In this study, a system was designed to examine the kinetics of inactivation of Listeria monocytogenes on the surface of a model food as affected by both water activity and ClO2 concentration. The results of this study may be used to design suitable process conditions to inactivate foodborne pathogens on the surface of solid foods.
Technical Abstract: The aim of this study was to investigate the effect of water activity (aw) on inactivation of Listeria monocytogenes using gaseous chlorine dioxide (ClO2 (g)) under room temperature. Surface-inoculated tryptic soy agar (TSA) plates adjusted to 9 different water activity levels ranging from 0.994 to 0.429 were used as samples exposed to ClO2 (g) at 150, 250 and 350 ppm for different durations of treatment time. Results showed that the antimicrobial effect of ClO2 (g) significantly decreases as aw and ClO2 (g) concentration decrease. Nonlinear models, such as the modified Chick model and the Weibull model, were used to describe the inactivation kinetics of L. monocytogenes. The results showed that the modified Chick model, which is based on chemical reaction kinetic, was more suitable to describe the inactivation kinetics of L. monocytogenes (RMSE < 0.5 log CFU/g) than the Weibull model (RMSE < 1.0 log CFU/g). A multiple regression model was developed for the describing the effect of aw and ClO2 (g) concentration on bacterial inactivation. The results of this study may be used to design ClO2 (g) treatment processes to inactivate L. monocytogenes in low-moisture foods.