Effects of combined treatment of aqueous chlorine dioxide and UV-C or electron beam irradiation on microbial growth and quality in chicon during storage

The effects of combined treatment of aqueous ClO₂ and UV-C or electron beam irradiation on microbial growth and quality in chicon during storage at 4oC were investigated. Samples were treated separately with 50 ppm of ClO₂, 5 kJ/m2 of UV-C, 2, 5, 7, and 10 kGy of electron beam irradiation, as well as a combination of ClO₂ and UV-C or 2 kGy of electron beam irradiation. The populations of total aerobic bacteria as well as yeast and molds in the chicon samples were determined following each treatment. The populations of total aerobic bacteria in the chicon samples decreased by 1.49~2.92 log CFU/g following combined treatment of ClO₂ and UV-C irradiation compared to the control, whereas the populations of yeast and molds decreased by 1.63~1.78 log CFU/g. On the contrary, following combined treatment of ClO₂ and electron beam irradiation, the populations of total aerobic bacteria as well as yeast and molds in the chicon samples were undetectable during storage. Color measurements indicated that Hunter L*, a*, and b* values were not significantly different among the treatments during storage. These results suggest that combined treatment of ClO₂ and electron beam irradiation can be useful for improving microbiological safety in chicon during storage.