Evaluation of Chlorine Dioxide Gas Residues on Selected Food Produce

TLDR

Fresh produce consumption has risen, raising concerns about foodborne pathogen contamination and the need for effective sanitizers; chlorine dioxide gas is a broad‑spectrum oxidant with promising pathogen‑reduction efficacy, yet its residue safety on produce remains unexamined. The study aimed to evaluate residues of chlorine dioxide, chlorite, chlorate, and chloride on selected fresh produce surfaces after ClO₂ gas treatment. After ClO₂ gas treatment, produce surfaces were rinsed and the rinsate was analyzed for residues using N,N‑diethyl‑p‑phenylenediamine and ion chromatography, covering seven foods (tomatoes, oranges, apples, strawberries, lettuce, alfalfa sprouts, cantaloupe). Residues were very low on most foods, with only lettuce and alfalfa sprouts showing significantly higher levels; overall, chlorine dioxide gas leaves minimal to no detectable residues, posing no significant consumer risk and indicating its practical use as an effective pathogen‑inactivation technology.

Abstract

In recent years, the consumption of fresh fruits and vegetables has greatly increased, and so has its association with contamination of several foodborne pathogens (Listeria, Salmonella, and Escherichia coli). Hence, there is a need to investigate effective sanitizer systems for produce decontamination. Chlorine dioxide (ClO(2)), a strong oxidizing gas with broad spectrum and sanitizing properties, has previously been studied for use on selected fruits and vegetables. ClO(2) gas treatments show great potential for surface pathogen reduction; however its use from a residue safety standpoint has yet to be assessed. Thus, the objective of this study was to evaluate residues of ClO(2), chlorite, chlorate, and chloride on selected fresh produce surfaces after treatment with ClO(2) gas. A rinse procedure was used and water samples were analyzed by N, N-diethyl-p-phenylenediamine and ion chromatography method (300.0). Seven different foods--tomatoes, oranges, apples, strawberries, lettuce, alfalfa sprouts, and cantaloupe--were analyzed after ClO(2) treatment for surface residues. Very low residues were detectable for all the food products except lettuce and alfalfa sprouts, where the measured concentrations were significantly higher. Chlorine dioxide technology leaves minimal to no detectable chemical residues in several food products, thus result in no significant risks to consumers. Practical Application: Potential for chlorine dioxide gas treatments as an effective pathogen inactivation technology to produce with minimal risk for consumers.