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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #371350

Research Project: Ecology and Detection of Human Pathogens in the Produce Production Continuum

Location: Produce Safety and Microbiology Research

Title: Modeling the efficacy of gaseous chlorine dioxide against Listeria on apple surfaces

item GUAN, JIEWEN - Washington State University
item Lacombe, Alison
item TANG, JUMING - Washington State University
item Bridges, David
item RANE, BHARGAVI - Washington State University
item SABLANI, SHYAM - Washington State University
item Wu, Vivian

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2020
Publication Date: 4/2/2020
Citation: Guan, J., Lacombe, A.C., Tang, J., Bridges, D.F., Rane, B., Sablani, S., Wu, V.C. 2020. Modeling the efficacy of gaseous chlorine dioxide against Listeria on apple surfaces [abstract]. Meeting Abstract.

Interpretive Summary: N/A

Technical Abstract: Cross-contamination of pathogenic bacteria like Listeria monocytogenes on apples may occur during the industrial apple packing operations. Gaseous chlorine dioxide (ClO2) can be utilized during the storage of fresh produce to decontaminate the products. This study investigated the efficacy of gaseous ClO2 against Listeria innocua, as a surrogate for L. monocytogenes, on apple surfaces to support future prediction and development of commercial gaseous ClO2 decontamination in the apple storage conditions. A cocktail of five L. innocua strains (ATCC 33090, 33091, 43547, 51742, and BAA-680) was inoculated onto the calyx of three Fuji apples (250g each). An amber vacuum desiccator (45L) was modified as a treatment chamber. Gaseous ClO2 was generated inside the chamber, by mixing equal amounts of dry media (sodium chlorite and activating acids) in a sachet. A total of 24 apples (~6kg) including 21 uninoculated and three inoculated apples were treated for 1h. The initial dry media amount (inputs) were 10, 15, and 20g of each precursor. Temperature (19±1°C) and relative humidity (60—88%) were measured inside the chamber. After the treatment, the inoculated apples were washed with 30mL 0.1% peptone water. The rinse was enumerated on the PALCOM agar overlaid with TSA. The first-order model was used to fit the reduction data at different initial inputs. After 1h treatment, reductions of 0.84, 1.60 and 2.90 log CFU/mL were observed at ClO2 initial inputs of 10, 15, and 20g, respectively. The coefficient of determination (R2) was 0.911 for the first-order model. Log reductions were significantly (P<0.05) different between 10 and 20g initial inputs (N=3). This is the first study that models the efficacy of gaseous ClO2 inactivation against L. innocua on apples. The first-order model can be used to predict the inputs if target log reductions are known, which will provide insight into the development of industrial-scale treatments.