Efficacy of Gaseous Chlorine Dioxide Generated by Sodium Chlorite - Carbon Dioxide Reaction on Safety and Quality of Blueberries, Cherry Tomatoes, and Grapes

Authors: JIANG, TAO - Fujian Agricultural & Forestry University; GUO, FENGTING - Fujian Agricultural & Forestry University; FANG, TING - Fujian Agricultural & Forestry University; Hwang, Cheng An; Huang, Lihan

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2022
Publication Date: 8/2/2022
Citation: Jiang, T., Guo, F., Fang, T., Hwang, C., Huang, L. 2022. Efficacy of Gaseous Chlorine Dioxide Generated by Sodium Chlorite - Carbon Dioxide Reaction on Safety and Quality of Blueberries, Cherry Tomatoes, and Grapes. Food Control. 143. https://doi.org/10.1016/j.foodcont.2022.109288.
DOI: https://doi.org/10.1016/j.foodcont.2022.109288

Interpretive Summary: Fresh fruits and vegetables can be contaminated by human pathogens, potentially causing foodborne outbreaks. This study was conducted to inactivate Salmonella spp. and Listeria monocytogenes on blueberry, cherry tomato, and grape samples using chlorine dioxide gas by a reaction between sodium chlorite and carbon dioxide (dry ice) in a small portable treatment chamber. The results showed that 2.8 to 6.4 log CFU/g of the inoculated pathogens could be inactivated, depending on the fruit types and the amount of sodium chlorite used. The treatment did not seem to adversely affect the quality of fruits but prevented weight loss and tissue softening. The results of this study may be used by the fresh produce industry to enhance food safety.

Technical Abstract: This research evaluated the inactivation of Salmonella spp. and Listeria monocytogenes inoculated onto calyces of blueberries, stem scars of cherry tomatoes and surfaces of grapes using gaseous chlorine dioxide (ClO2) produced by reaction between sodium chlorite (NaClO2) and carbon dioxide (CO2). The inoculated samples were treated with ClO2 gas in a treatment chamber for 3 h. The results suggested that ClO2 exposures of 366 to 477 ppm-h achieved 2.8 to 3.8, 2.4 to 4.3, and 3.8 to 6.4 log CFU/g in inactivation of both pathogens on blueberries, cherry tomatoes, and grapes, respectively. The inactivation of pathogens on grapes was significantly greater (p < 0.05) than those on blueberries and cherry tomatoes, likely due to the difference in the inoculation sites. During an 8-day post-treatment storage at 25°C, the color attributes (L*, a*, and b*) of the fruit samples were not or little affected by either storage time or ClO2 treatment. The weight loss of treated and untreated samples during the storage was more affected by and increased with storage time but was higher in the untreated samples. The fruit hardness was significantly affected by and decreased with storage time. The hardness was higher in ClO2-treated blueberry and grape samples, but not in cherry tomato samples. The residual ClO2 on treated fruits, ranging from 0.08 to 0.35 mg/kg, was not affected by the storage time, but it was the highest in blueberry and the lowest in cherry tomato samples. These results clearly demonstrated that this method of gaseous ClO2 generation can be used to reduce pathogens on the fruit samples during postharvest intervention and storage, while improving product safety and quality.