Low concentrations of chlorine dioxide gas reduce postharvest diseases and improve storage quality of sugarbeet

Authors: DANGI, SANDESH - North Dakota State University; Herges, Grant; Eide, John; Fugate, Karen; Bolton, Melvin; LIU, ZHAOHUI - North Dakota State University; Smith, David; Kandel, Shyam

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/2025
Publication Date: 8/13/2025
Citation: Dangi, S., Herges, G.R., Eide, J.D., Fugate, K.K., Bolton, M.D., Liu, Z., Smith, D.J., Kandel, S.L. 2025. Low concentrations of chlorine dioxide gas reduce postharvest diseases and improve storage quality of sugarbeet. Postharvest Biology and Technology. 230. https://doi.org/10.1016/j.postharvbio.2025.113830.
DOI: https://doi.org/10.1016/j.postharvbio.2025.113830

Interpretive Summary: The sugarbeet industry is valued at $23 billion a year for the US economy and contributes significantly to the nation’s food supply. After harvest in the autumn, sugarbeet roots are stored in factory yards, outdoor piles, or ventilated sheds until processing for sugar extraction. During storage, sugarbeet roots are susceptible to infection by a variety of fungal and bacterial pathogens which cause significant sugar loss and the formation of non-sugar compounds which interfere with the sugar refinement process. Currently, there are no effective measures available to mitigate postharvest storage diseases in sugarbeets. We used a low concentrations of chlorine dioxide (ClO2) gas to investigate its effectiveness at preventing the growth of sugarbeet storage pathogens and whether postharvest sugarbeet quality was improved. Germination of a major pathogen, Penicillium vulpinumm, was effectively prevented after exposure to the gas. In additional experiments, sugarbeet roots stored at 5 °C for up to 7 weeks with low concentrations of gas had reduced pathogen growth and reduced tissue damage compared to control roots. Nominally higher concentrations of sucrose were recovered in ClO2-treated sugarbeet roots compared to controls. Importantly, carbohydrate impurities decreased with ClO2 treatment. Our findings suggest that ClO2 might be effective at controlling storage diseases and preventing the formation of carbohydrate impurities in stored sugarbeet. Our studies, conducted in a controlled environment, lay the foundation for larger-scale experiments under commercial storage conditions.

Technical Abstract: Postharvest diseases cause significant sucrose loss in sugarbeet during storage, affecting millions of tons each year. Numerous pathogens infect sugarbeet roots during storage, significantly reducing sucrose content. No effective control measures are currently available to minimize sugar loss caused by storage diseases in sugarbeet. Low concentrations of chlorine dioxide (ClO2) were used in a closed system to test whether the gas could reduce or eliminate sugarbeet storage pathogens. Penicillium vulpinum spores exposed to 5 or 10 mg L-1 ClO2 gas for 1 h significantly reduced conidial germination, whereas exposure to 20 or 40 mg L-1 ClO2 gas eliminated nearly 100% of conidial viability within 1 h. In storage experiments, ClO2 application also reduced pathogen growth and associated tissue damage during sugarbeet storage up to 7 weeks. Storage pathogens, including Penicillium spp., Pichia membranifaciens, and Leuconostoc suionicum, were eliminated from ClO2 treated sugarbeet roots. Sucrose retention was numerically higher in ClO2-treated roots than controls but was not statistically different. Importantly, the formation of invert sugars, impurities that impede the sucrose extraction process, decreased with ClO2 treatments as low as 25 mg kg-1 of sugarbeet roots compared to controls. In addition, raffinose content was reduced by treatment with 50 and 100 mg of ClO2 kg-1 of sugarbeet root. Our findings suggest that ClO2 might be effective at mitigating storage diseases and sucrose catabolism in stored sugarbeet. This pilot study, conducted in a controlled environment, provides baseline data for planning larger-scale experiments simulating commercial storage conditions.