• 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.

• 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.29 no.4
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• pp.499-505
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• 2016

To improve the shelf-life of mushrooms, Lentinula edodes GNA01 mushrooms were treated with gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 5~10 ppm for 5 days at $20^{\circ}C$ and the weight loss rate as well as the changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples were decreased slightly, and there were no differences during the storage period. However, the weight of the control changed faster than those of the $ClO_2$ gas treated samples during storage period. The pH in the control and in the $ClO_2$ gas treated samples were decreased during storage period, but the samples treated with 5 and 7 ppm $ClO_2$ gas were the least changed. On the other hand, the samples treated with 10 ppm $ClO_2$ gas showed no difference from the other treatments during 4 days, but the pH was lower than that of the control on the fifth day. The lightness of inside and outside in mushroom were decreased whereas redness and yellowness were increased during storage period. However, color changes in the $ClO_2$ gas treated samples were lower than those of the control. Especially, the samples treated with 5 and 7 ppm $ClO_2$ gas were the least changed. The texture of the mushroom were decreased consistently during storage period. The texture of the control changed faster than those of the $ClO_2$ gas treatments during 5 days. Especially, the samples treated 5 ppm $ClO_2$ gas were the least changed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.955-959
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• 2006

Effects of chlorine dioxide ($ClO_2$) on weight loss, polyphenol oxidase activity, and microbial change of fresh mushrooms (Agricus bisporus Sing) were investigated. Mushrooms were treated with 5, 10, and 50 ppm of $ClO_2$ solution. Mushrooms were stored at room temperature and $4^{\circ}C$. Weight loss for $ClO_2$ treated mushrooms was smaller than that of the control group. Polyphenol oxidase activity of the $ClO_2-treated$ samples stored at room temperature increased until day 2 of storage and then decreased, and the activity of the samples stored bacteria, yeast and mold counts than the control during storage. Aerobic bacterial counts for 50 ppm of $ClO_2$ treatment at $4^{\circ}C$ increased from $1.62{\times}10^2\;CFU/g\;to\;1.66{\times}10^7\;CFU/g$ at day 10 of storage, while control groups were from $1.00{\times}10^3\;CFU/g\;to\;3.72{\times}10^8\;CFU/g$. These results indicate that $ClO_2$ treatment could be useful in improving the quality and microbial safety of mushrooms.

• Food Science and Preservation
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• v.20 no.4
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• pp.459-466
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• 2013

This study was carried out in order to investigate sterilization effect and to extend storage periods of the Rubus coreanus by treating with tap water (TW), electrolyzed water (EW) and aqueous chlorine dioxide ($ClO_2$). After each treatment plot was soaked with 10, 50, 100, 200 ppm in each sterilizing solution within 30 sec, each treatment was compared during the storage time at room temperature and refrigerator temperature. As results of total plate count according to temperatures and periods, the microbial sterilizing power of each treatment plot was bigger at EW and $ClO_2$ treatment plots than the TW treatment plot; however, it sharply increased on the high concentration $ClO_2$ treatment plot. Futhermore, the cold storage treatment plot had more outstanding microbial sterilizing power than the room temperature treatment plot. As a result of observing the surface of the Rubus coreanus using scanning electron microscope (SEM), no microbe was seen in EW and $ClO_2$ treatment plot. The results of measuring enzyme activity showed a more significant decrease in EW and $ClO_2$ solutions treatment plot than TW treatment plot but gradually increased with time. The contents of total polyphenol revealed similar values on each treatment. The EW and $ClO_2$ treatment of the Rubus coreanus could be considered as good methods for inhibiting microbial growth in fresh vegetables and fruit, thereby contributing to quality maintenance.

• Food Science and Preservation
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• v.15 no.5
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• pp.769-773
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• 2008

Aqueous chlorine dioxide ($ClO_2$) treatment of Samgae chicken was evaluated in terms of microbial safety and quality during refrigerated storage. Samgae chicken samples were treated with 0, 50, or 100 ppm of $ClO_2$ solution, and stored at $4^{\circ}C$ for 10 days. $ClO_2$ treatment significantly decreased the populations of total aerobic bacteria. One-hundred ppm $ClO_2$ treatment reduced the initial populations of total aerobic bacteria by 0.73 log CFU/g. The pH and volatile basic nitrogen values of Samgae chicken increased during storage, with no significant between-treatment difference. Sensory evaluation results showed that the quality of chicken treated with $ClO_2$ prior to refrigerated storage was better than that of the control. These results suggest that $ClO_2$ treatment could be useful in improving the microbial safety and quality of Samgae chicken.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1337-1342
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• 2008

This study was conducted to investigate effects of chemical sanitizers on inhibiting foodborne pathogens, such as Listeria monocytogenes (L. monocytogenes), Salmonella Typhimurium (S. Typhimurium), and E scherichia coli O157:H7 (E. coli O157:H7), on cabbages. Cabbages were inoculated with the culture cocktail of pathogens and treated with water, 100 ppm commercial chlorine, and 50, 100, and 200 ppm chlorine dioxide ($ClO_2$) for 1, 5, and 10 min at room temperature ($22{\pm}2^{\circ}C$). Treatments with water did not significantly reduce levels of three pathogens whereas other treatments with chemical sanitizers significantly reduced levels of three pathogens. Treatment with 200 ppm $ClO_2$ for 10 min was the most effective at inhibiting pathogens and reduction levels were 1.90, 1.92, and 1.98 log CFU/g for L. monocytogens, S. Typhimurium, and E. coli O157:H7, respectively. Levels of reduction were increased with the increase of $ClO_2$ concentrations. When chemically injured cells were investigated, there were no significant differences on the levels of injured cells between before and after treatment with commercial chlorine and $ClO_2$. These results suggest that $ClO_2$ can be used as an alternative sanitizer for reducing pathogens on fresh produces.

• 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

• Journal of Environmental Science International
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• v.11 no.3
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• pp.241-246
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• 2002

One of the Musty and earthy smell compounds in raw water is generally attributed to 2-methylisoborneol (2-MIB). It is well known that activated carbon and oxidants such as $O_3$, Cl $O_2$, are effective ways to control 2-MIB. In isotherm equilibrium experiments, 2-MIB in distilled water was much more adsorbed to the activated carbon(A/C) than raw water containing dissolved organic carbon (DOC). The Freundlich constants(k) of distilled water and raw water were 3.36 and 0.049, and 1/n values were 0.80 and 0.42, respectively. The 2-MIB residual rate were Y = $e^{-0}$.55x/~ $e^{-0}$.54x/ with Ozone( $O_3$) dose by 5 minutes contact time at the 241 and 353 ng/L initial concentrations. The 2-MIB residual rate were Y = $e^{-0}$.32x/~ $e^{-0}$.35x/ with Chlorine dioxide(Cl $O_2$) dose by 15 minutes contact time at the 89 and 249 ng/L initial concentrations. 2-MIB was decreased from 1911 ng/L to 569ng/L by post-ozonation(70%removal efficiency) and removal efficiencies of 2-MIB by the following 4 kinds Granular Activated Carbon(GAC) process such as coal base, coconut base, wood base and zeolite＋carbon base were 95.8, 89.5, 88.4, and 93.7% respectively.ely.

• 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.