Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2016
Publication Date: 4/1/2017
Citation: Hwang, C., Huang, L., Wu, V.C. 2017. In-situ generation of chlorine dioxide for surface decontamination of produce. Journal of Food Protection. 80(4):567-572.
Interpretive Summary: Fruits and vegetables are frequently contaminated with bacterial pathogens and implicated in foodborne illnesses. This study developed a surface decontamination method for produce. The method consisted of soaking produce in 1.6% sodium chlorite for 30 min, drying for 20 min, and soaking in 6 mM HCl for 30 min. Results showed that the decontamination method significantly reduce two pathogens commonly associated with fresh produce. The effect was attributed to coated chlorite on produce reacting with HCl to produce chlorine dioxide on the surface and inactivating the pathogens. The decontamination method can be used by the produce industry to improve the microbiological quality and safety of fresh produce.
Technical Abstract: Fruits and vegetables, particularly fresh-cut products, are frequently contaminated with bacterial pathogens and implicated in foodborne illnesses. The objective of this study was to develop a unique in-situ sequential surface decontamination method for produce using sodium chlorite and acid. The cantaloupe rinds, cucumber peels, stem scare areas of grape tomatoes and leaves of baby spinach, surface-inoculated with Salmonella spp. or L. monocytogenes, were first submerged in 1.6-4% sodium chlorite solutions for 10 or 30 min and then dried for 20 min. The treatments were continued by soaking in 6 mM HCl for 10 or 30 min. The samples were also treated with sodium chlorite or HCl alone and their premixed solutions for comparison. The treatments with sodium chlorite or HCl alone and their premixed solutions reduced the counts of both pathogens by 1-3 log CFU/g of on the samples, while complete elimination (5.1-5.6 log CFU/g) was observed with the new in-situ sequential surface treatment. The effect was likely attributed to the formation of active chlorine dioxide within the food matrix by the in-situ reaction between sodium chlorite absorbed by the produce and the acid. The results suggest that the sequential treatment of produce using sodium chlorite and acid is a potentially effective treatment for elimination of foodborne pathogens on produce.