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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Animal Metabolism-Agricultural Chemicals Research » Research » Publications at this Location » Publication #311653

Research Project: METABOLIC FATE OF CHEMICAL AND BIOLOGICAL CONTAMINANTS

Location: Animal Metabolism-Agricultural Chemicals Research

Title: Chloroxyanion residue quantification in cantaloupes treated with chlorine dioxide gas

Author
item Kaur, Simran - Purdue University
item Smith, David
item Morgan, Mark - University Of Tennessee

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2015
Publication Date: 9/1/2015
Publication URL: http://handle.nal.usda.gov/10113/61742
Citation: Kaur, S., Smith, D.J., Morgan, M.T. 2015. Chloroxyanion residue quantification in cantaloupes treated with chlorine dioxide gas. Journal of Food Protection. 78(9):1708-1718.

Interpretive Summary: Human disease may be caused by harmful bacteria present on fruits, vegetables, and melons. Traditionally, water rinses have been fairly effective at removing disease organisms from vegetables or melons having smooth surfaces, but water rinses are fairly ineffective at removing bacteria from rough tissue surfaces or surfaces that may be damaged or scarred. Chlorine dioxide dissolved in waster is an excellent antibacterial agent that is currently used for many food applications; chlorine dioxide gas is also very effective at eliminating pathogens and rot organisms on fruits and vegetables. The use of chlorine dioxide gas, however, has not been approved by regulatory authorities for use on human foods, mostly because chemical residues have not been fully characterized. Data generated by this study strongly suggests that chlorine dioxide may be used to treat cantalope without the formation of undesirable chemical residues.

Technical Abstract: Previous studies show that treatment of cantaloupes with chlorine dioxide (ClO2) gas at 5 mg/L for 10 minutes, results in a significant reduction (p<0.05) in initial microflora, an increase in shelf life without any alteration in color, and a 4.6 and 4.3 log reduction of E. coli O157:H7 and L. monocytogenes respectively. This treatment could result in the presence of chloroxyanion residues such as chloride (Cl-), chlorite (ClO2-), chlorate (ClO3-) and perchlorate (ClO4-), which, apart from chloride, are a toxicity concern. Radiolabeled chlorine dioxide (36ClO2) gas was used in order to describe the identity and distribution of chloroxyanion residues in cantaloupe subsequent to fumigation of cantaloupe (n=6). Each treated cantaloupe was separated into rind, flesh and mixed (rind+flesh) sections, which were blended and centrifuged to give the corresponding sera fractions. Radioactivity detected, ratio of radioactivity to mass of chlorite in initial ClO2 gas generation reaction and distribution of chloroxyanions in serum samples were used to calculate residue concentrations in flesh, rind and mixed samples. Anions detected in the cantaloupe were Cl- (~90%) and ClO3- (~10%), located primarily in the rind (19.3±8.0 µg Cl- /g rind slurry and 4.8±2.3 µg ClO3-/g rind slurry, n=6). Cantaloupe flesh (~200 g) directly exposed to 36ClO2 treatments only showed presence of Cl- residues (8.1 ±1.0 µg Cl-/ g flesh, n=3). Results indicate chloroxyanion residues Cl- and ClO3- are only present in the rind of whole cantaloupes treated with ClO2 gas. During cutting, residues may be transferred to the fruit flesh, however, Cl- is not considered toxic and ClO3- exposure would be too low to be of concern. In the case of fruit flesh, directly exposed to ClO2 only nontoxic Cl- was detected.