The application of high-concentration short-time chlorine dioxide treatment for selected specialty crops including Roma tomatoes (Lycopersicon esculentum), cantaloupes (Cucumis melo ssp. melo var. cantaloupensis) and strawberries (Fragaria×ananassa)

Abstract

The effects of high-concentration short-time chlorine dioxide (ClO2) gas treatment on food-borne pathogens inoculated onto the surface of tomatoes, cantaloupes, and strawberries were studied. Produce were spot-inoculated with a mixture of Salmonella enterica (serotypes Montevideo, Javiana and Baildon), Escherichia coli O157:H7 (serotypes 204 P, EDL 933 and C792) or Listeria monocytogenes (serotypes Scott A, F 5069 and LCDC 81-861), and treated with ClO2 gas at 10 mg/l for 180 s. After ClO2 gas treatment, surviving populations were determined and shelf-life studies were conducted (microbial spoilage population, change in color and overall appearance). Significant microbial reduction (p < 0.05) was observed for all treated samples. Nearly a 5LogCFU/cm(2)Salmonella reduction was found on tomatoes, cantaloupe and strawberries, while a ~3LogCFU/cm(2) reduction was observed for E. coli and Listeria on all produce surfaces. E. coli and Listeria appeared to be more resistant to ClO2 gas as compared to Salmonella spp. Treatments significantly (p < 0.05) reduced initial microflora population, while produce color surface was not significantly influenced, as compared to the control (p > 0.05). Results obtained suggest the potential use of high-concentration short-time ClO2 gas treatment as an effective online pathogen inactivation technology for specialty crops in large-scale produce packing operations.