Distribution and chemical fate of [36Cl]chlorine dioxide gas on avocados, eggs, onions, and sweet potatoes

Authors: Smith, David; Scapanski, Abigail

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2020
Publication Date: 4/20/2020
Citation: Smith, D.J., Scapanski, A.R. 2020. Distribution and chemical fate of [36Cl]chlorine dioxide gas on avocados, eggs, onions, and sweet potatoes. Journal of Agricultural and Food Chemistry. 68:5000-5008. https://doi.org/10.1021/acs.jafc.0c01466.
DOI: https://doi.org/10.1021/acs.jafc.0c01466

Interpretive Summary: Chlorine dioxide gas is very effective at eliminating microbiological contaminants from a variety of fruits, vegetables, melons, seeds, and even eggs. The gas has been proposed for several applications on human foods that would improve food safety through elimination of pathogens, or food preservation through the elimination of rot organisms. The gaseous chlorine dioxide, however, has not been approved by regulatory authorities for use on human foods other than tomatoes or cantaloupe. Data generated by this study show that chlorine dioxide gas is almost exclusively deposited on the surfaces of eggs, avocados, onion, and sweet potato. Further, most of the chlorine dioxide in the food products tested was converted to chloride ion, a nutrient required for life. The study suggests that chemical residues are not a major obstacle for the development of chlorine dioxide gas as safe treatment for a variety of food products.

Technical Abstract: Fate and distribution studies were conducted with [36Cl]-chlorine dioxide in avocados, eggs, onions, and sweet potatoes. Experiments utilized sealed, darkened chambers, 5 mg of 36ClO2 (g) and two-hour exposure periods. Total radioactive residues were quantified in gas purges, tank rinses, reaction chambers, and on fractions specific to each food. Deposition of radioactive residue was mostly a surface phenomenon; transfer of radioactivity into albumen occurred in egg, but radioactivity did not penetrate the onion tunic and only small amounts of activity were present in avocado flesh. Potato skin contained essentially all the potato radiochlorine. Regardless of food product, nearly all radioactive residue was present in edible tissues as chloride ion; chlorite ion was present only in egg rinse water. Small amounts (10% or less) of radioactivity were present as chlorate ion, which would be a useful marker compound for chlorine dioxide sanitation.