• Food Science and Preservation
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• v.15 no.5
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• pp.754-759
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• 2008

The effect of citric acid-aqueous chlorine dioxide ($ClO_2$) treatment of radish seeds artificially contaminated with Salmonella typhimurium was studied. Radish seeds were inoculated by immersion, in more than 106 log CFU/g seed, of a suspension of S. typhimurium, dried, and stored sealed at $4^{\circ}C$ Radish seeds soaked in 200 ppm aqueous ClO2 solution for 10 min showed a bacterial reduction of 1.08 log CFU/g seed, and the lowering of microbial burden noted in seeds soaked in 2% (w/v) citric acid solution for 10 min was 2.89 log CFU/g seed. Next, radish seeds were exposed to 0.5% (v/v) glycerol solution for 10 min either before or after treatment with 200 ppm aqueous ClO2 or 2% (w/v) citric acid for 10 min. Glycerol exposure after citric acid treatment reduced bacteria by 3.46 log CFU/g seed, and glycerol treatment after aqueous $ClO_2$ treatment reduced the microbial burden by 2.14 log CFU/g seed. Both glycerol treatments yielded better elimination of S. typhimurium than did a single treatment with either citric acid or aqueous $ClO_2$. Radish seeds inoculated with S. typhimurium were treated throughout the entire growth period. Although radish seed treatment was effective, treatment by citric acid and aqueous $ClO_2$ after sprouting was not effective to eliminate S. typhimurium.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.396-403
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• 2015

To improve the shelf-life of cherry tomato, samples were treated with aqueous chlorine dioxide ($ClO_2$) at 30 ppm for 0~30 minutes and the weight loss rate as well as the changes in physico-chemical and sensory properties of treated samples were investigated. Weight change in the control and in the samples with aqueous $ClO_2$ treatment were decreased slightly, and there were no difference during the storage period. There were no differences in soluble solid content among the treatments and during the storage period. There were no differences in the firmness of samples among the treatments but the firmness of the aqueous $ClO_2$ treated samples were decreased slower than that of the control samples. No significant changes in lightness, redness and yellowness of the controls and the samples by aqueous $ClO_2$ treatment were observed during 4 weeks storage period. The sensory parameters including taste, flavor, color, texture and overall acceptance at the initial period did not differ among the treatments. The scores for taste, texture and overall acceptance of the control were decreased faster than those of the aqueous $ClO_2$ treated samples when 3 weeks reached.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.449-450
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• 2004

• Food Science and Preservation
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• v.16 no.6
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• pp.1013-1017
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• 2009

The effects of aqueous chlorine dioxide ($ClO_2$) or fumaric acid treatment on the reduction of microbial populations in hot pepper, ginger, and carrot, were investigated. Hot pepper, ginger, and carrot were treated with 5, 10, or 50 ppm of $ClO_2$, or 0.1, 0.3, or 0.5%(v/v) fumaric acid solution for 5 min. Aqueous $ClO_2$ or fumaric acid treatment significantly decreased the populations of both total aerobic bacteria, and yeasts and molds. In particular, 50 ppm $ClO_2$ treatment of hot pepper reduced total aerobic bacteria and yeast and mold levels, by 1.52 and 1.81 log CFU/g, respectively, whereas 0.5% (v/v) fumaric acid treatment eliminated all aerobic bacteria and all yeasts and molds. In addition, 50 ppm $ClO_2$ treatment of ginger reduced the populations of total aerobic bacteria, and yeasts and molds, by 0.53 and 0.92 log CFU/g, respectively, and 0.5% (v/v) fumaric acid treatment also decreased total aerobic bacteria, and yeast and mold levels, by 1.44 and 1.28 log CFU/g, respectively. With carrots, 50 ppm $ClO_2$ treatment decreased total aerobic bacteria, and yeasts and molds, by 1.76 and 2.22 log CFU/g, whereas 0.5% (v/v) fumaric acid treatment reduced the levels of these microorganisms by 1.94 and 1.73 log CFU/g, respectively. These results indicate that aqueous $ClO_2$ or fumaric acid treatment is useful for reducing microbial populations in hot peppers, ginger, and carrots.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.83-87
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• 2014

The effects of combined treatment of aqueous chlorine dioxide ($ClO_2$) and fumaric acid on the microbial growth in fresh-cut paprika were investigated. After the combined treatment, the populations of total aerobic bacteria and inoculated Listeria monocytogenes in the paprika sample were reduced by 0.82 and 1.21 log CFU/g, respectively, compared to those of the control. In addition, after 10 d of storage at $10^{\circ}C$, the populations were decreased by 1.21 and 2.10 log CFU/g, respectively. The predictive model for the populations of total aerobic bacteria and L. monocytogenes in the paprika was applied during storage. The prediction equation using Gompertz model was appropriate, based on the statistical analysis such as accuracy factor and bias factor. These results suggest that the combined treatment of aqueous $ClO_2$ and fumaric acid can be an effective technology for microbial decontamination and it can improve microbial safety by decreasing maximum growth rate and increasing lag time of bacteria in the fresh-cut paprika.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.402-407
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• 2012

The effects of a combined treatment of aqueous chlorine dioxide ($ClO_2$) and ultraviolet-C (UV-C) irradiation on microbial growth in celery and cherries were investigated. Celery and cherry samples were treated with 50 ppm $ClO_2$, UV-C at dose of 10 kJ/$m^2$, and a combination of $ClO_2$ and UV-C. The changes in the counts of Escherichia coli O157:H7 inoculated in the celery and cherries as well as those of total aerobic bacteria, yeast and molds in the celery and cherries were investigated after each treatment. After the combined treatment of aqueous $ClO_2$ and UV-C irradiation, the populations of E. coli O157:H7 in the inoculated celery and cherries were reduced by 2.8 and 3.0 log CFU/g, respectively, compared to those of the control. For the un-inoculated celery and cherries, the populations of total aerobic bacteria were reduced by 2.9 and 1.8 log CFU/g, respectively, compared to the control. In addition, the populations of yeast and molds were decreased by 1.8 and 1.2 log CFU/g, respectively. These results suggest that the combined treatment of 50 ppm $ClO_2$ and UV-C at a dose of 10 kJ/$m^2$ would be an effective technology for decontamination and improving the microbiological safety in celery and cherries during chilled storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.245-252
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• 2011

The combined effects of 10 kJ/$m^2$ ultraviolet-C (UV-C) with 50 ppm aqueous chlorine dioxide ($ClO_2$) on the qualities of red chicory and pak choi were examined. After the treatment, the samples were stored at $4{\pm}1^{\circ}C$ for 7 days. The combined treatment of $ClO_2$/UV-C reduced the initial populations of total aerobic bacteria in the red chicory and pak choi by 2.64 and 2.55 log CFU/g, respectively, compared to those of the control. Also, the populations of yeast and molds in the red chicory and pak choi by combined treatment were reduced by 2.41 and 2.00 log CFU/g, respectively. In addition, after 7 days of storage the total aerobic bacteria populations in the red chicory and pak choi were reduced to 3.71 and 3.93 log CFU/g, compared to 6.31 and 6.62 log CFU/g for the control, resulting in a significant decrease. Hunter L, a, and b values of red chicory and pak choi were not significantly different among the treatments. Non-thermal treatment caused a negligible change in sensory evaluation. These results suggest that the combined treatment of 50 ppm $ClO_2$ with 10 kJ/$m^2$ UV-C can be useful for maintaining the qualities of red chicory and pak choi.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.240-246
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• 2012

This study evaluated the efficacy of strong acidic electrolyzed water (SAcEW), low alkaline electrolyzed water (LAlEW) and aqueous chlorine dioxide (ACD) for reducing pathogenic bacteria($Escherichia$ $coli$, $Bacillus$ $cereus$, $Salmonella$ Typhimurium, $Stapylococcus$ $aureus$) on Chinese cabbage. Artificially inoculated Chinese cabbage was immersed for 1, 5 and 10 min with TW, NaClO, EW and ACD. Generally, leaves showed more effective reduction than stems. Regarding the inhibitory effect, ACD treatment showed the highest effects rather than other treatments. When Chinese cabbage was immersed for 3 min in sterilized water, it was reduced to a minimum of 1.33 log CFU/g at LAlEW and a maximum of 4.70 log CFU/g at ACD. Compared to NaClO, ACD and LAlEW which showed a reduction of 3.2 log CFU/g ($Sal.$ Typhimurium) and 2.7 log CFU/g($B.$ $cereus$), respectively. Furthermore, the others had similar inhibitory effects compared to NaClO.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.404-409
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• 2019

This study was performed to determine the optimum conditions for the production of gaseous chlorine dioxide ($ClO_2$) from aqueous $ClO_2$ (HCl+$NaClO_2$). When 1 N HCl was reacted with various concentrations of $NaClO_2$ (50,000-500,000 mg/mL), the highest concentration (695 mg/L) of gaseous $ClO_2$ was obtained from the aqueous $ClO_2$ containing $100,000{\mu}g/mL$ $NaClO_2$. Next, the effects of relative humidity (RH; 43, 85, and 100%) and temperature (4, 12, and $25^{\circ}C$) on the production of gaseous $ClO_2$ were investigated. It was observed that the concentration of gaseous $ClO_2$ was increased as RH was decreased, or the temperature was increased. Finally, it was confirmed that the amount of gaseous $ClO_2$ was highly correlated ($R^2=0.9546-0.9992$) with the volume of aqueous $ClO_2$. The results of this study provide useful information for designing a sanitization program using gaseous $ClO_2$ under various environmental conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1622-1627
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• 2007

This study was undertaken to evaluate the effects of chlorine dioxide on reducing E. coli O157:H7 and L. monocytogenes on broccoli served in foodservice institutions. Broccoli samples inoculated with $10^6$ CFU/mL of E. coli O157:H7 and L. monocytogenes were treated with chlorine dioxide. Treatments with 5, 10, and 20 ppm for 1, 5, and 10 min were not sufficient in controlling E. coli O157:H7 on broccoli. L. monocytogenes were effectively reduced by $2.19{\sim}2.48log\;CFU/g\;and\;3.31{\sim}3.87log\;CFU/g$ with 10 and 20 ppm chlorine dioxide for 1, 5, and 10 min treatment, respectively, compared with the control. E. coli O157:H7 and L. monocytogenes population were significantly negatively correlated with concentration and treatment time of chlorine dioxide. These results show that the use of chlorine dioxide was effective in sanitizing L. monocytogenes on broccoli and the level of concentration was more associated with populations of E. coli O157:H7 and L. monocytogenes than treatment time of chlorine dioxide on broccoli.