• Journal of fish pathology
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• v.37 no.1
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• pp.139-145
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• 2024

In this study, nylon mash and silicone tube mainly used as shrimp farm equipment were contaminated with Enterocytozoon hepatopenaei (EHP) which is the cause of Hepatopancreatic microsporidiosis (HPM), and were treated with calcium hypochlorite or UV-C disinfection methods for EHP eradication. As a result, similar with the control group (not disinfected), EHP was detected on the nested PCR until the 10 days in the UV-C single treated group. On the other hand, EHP was not detected from 7 days in calcium hypochlorite single treated group (total concentration 200 ppm as available chlorine), and combination of calcium hypochlorite and UV-C treated group revealed no detection of EHP from 3 days. It is appropriate that treated with UV-C and calcium hypochlorite for 3 days or single treated with calcium hypochlorite for 7 days to eradicate EHP on contaminated instrument used in shrimp farms. In contrast, disinfection effect of only using UV-C is very low.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.235-242
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• 2007

This study was conducted to investigate the effect of aerosolized chemical sanitizers on inhibiting foodborne pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Five domestic commercial sanitizers subjected to five groups of sanitizer (chlorine-based, hydrogen peroxide-based, Iodophor-based, quaternary ammonium-based, and alcohol-based sanitizers) were aerosolized by an aerosol generator into a model cabinet and treated in laboratory media containing three pathogens for 1 h at room temperature. Aerosolized hydrogen peroxide-based and quaternary ammonium-based sanitizers were effective at inhibiting levels of E. coli O157:H7 (ca. 4-9 log reductions) whereas other aerosolized sanitizers such as chlorine-based, Iodophor-based, and alcohol-based sanitizers did not significantly reduced the levels of E. coli O157:H7. For S. typhimurium, the only aerosolized hydrogen peroxide-based sanitizer was effective and resulted in ca. 5-9 log reduction. Aerosolized hydrogen peroxide-based, Iodophor-based, and quaternary ammonium-based sanitizers significantly reduced levels of L. monocytogenes and especially, aerosolized quaternary ammonium-based sanitizer was strongly effective to kill L. monocytogenes, resulted in higher than 8.8 log reduction. And there was no special trend in inhibitory efficacy of sanitizers aerosolized by 1.6 or 2.4 MHz aerosol generators. From these results, aerosolization has great potential for use in commercial applications however it's efficacy could be very different depending on type of sanitizers.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.43-50
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• 2011

This study was conducted to verify the effect of chlorine dioxide ($ClO_2$) on odor reduction at a commercial swine facility consisting of a windowless piglet barn and a grower/fattening barn. The windowless piglet barn used a duct ventilation system. Air velocity at very below the upper duct was 4.53 m/s. Air velocity at the lower space around the living space of pigs in the grower/fattening barn was 0.26 m/s. $NH_3$ concentration was around 9ppm and less than 3 ppm before and after the $ClO_2$ spraying, respectively, which was over 70% reduction. There was no $H_2S$ detection. $NH_3$ concentrations measured in the windowless grower/fattening barn and at the exhausted air were 26 ppm and 11ppm, respectively. $NH_3$ concentration at a biocurtain outside was less than 1 ppm. Hence, $ClO_2$ spraying at windowless barns was effectively decreased malodor such as $NH_3$.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.31-37
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• 2018

In the surface contamination test using the end-window Geiger-Muller type counter, the wrap is used as a method for protecting the detector exposed to the outside in order to measure the beta-rays. We analyze the effect of this method on the measurement rate and the correction factor, and wanted to make it clear to radiation workers that excessive use of the wrap can affect the measured value of the beta-rays. The experimental method was to compare and analyze the change of the beta-rays measurement counting rate and the calibration factor according to the wrap thickness using the beta-rays with different energy of 3 KBq, 1.5 KBq and 0.3 KBq. The subjects of this study were the end-window Geiger-Muller type counter which were held at the calibration center certified by Korea Laboratory Accreditation Scheme (KOLAS) in March 2012, Cl-36 (Chlorine) and Sr-90 (Strontium) were used as the source of beta radiation. The measurement counting rate decreased with increasing wrap thickness, and the calibration factor increased with increasing wrap thickness. Since the changes of the measurement counting rate and the calibration factors can reduce the accuracy of the instrument readings, but also have a significant impact on detector contamination and damage, so there is a need to find out what thickness of wrap is most effective. If we using a wraps with thickness that show a low rate of change of the measurement counting rate and the calibration factor, it will protect the detector and minimize the effect on the measured value of the beta-rays.

• Food Science and Preservation
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• v.21 no.4
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• pp.468-472
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• 2014

The effect of pre-storage treatments was investigated to control the occurrence of fruit skin stain in 'Niitaka' pears. The incidence of fruit skin stains was significantly reduced when the fruits were stored in paper bags with a yellow inner color, compared to when they were stored in paper bags with blue and red inner colors. Additionally, the pear fruits that were harvested seven days earlier than their optimum maturity date developed less fruit skin stains in cold storage and retained their quality. Storage in polyethylene (PE) bags did not control the occurrence of fruit skin stains as effectively as did bag-free storage or storage in calcium-coated bags. The dipping of the pear fruits in a chlorine dioxide and calcium solution was highly effective in reducing the fruit skin stains compared to when they were not dipped or when they were dipped only in distilled water. In particular, a 1,500 times diluted solution of sodium dichloroisocyannurate (NaDCC) reduced the incidence of fruit skin stains and the size of the lesions. No stain was observed on the skin of the fruit with a water content lower than 67.7% (w/v) during its storage. In conclusion, packaging pear fruits in bags with an inner calcium coat and dipping them in a chlorine dioxide, calcium, or NaDCC solution can effectively reduce their skin stains during their storage.

• Journal of Animal Environmental Science
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• v.18 no.sup
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• pp.1-6
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• 2012

This study was conducted to verify the effect of chlorine dioxide ($ClO_2$) on odor reduction at a commercial swine facility consisting of a compost ficility. Compost facility in $NH_3$ concentration was around 550 ppm and less than 78 ppm before and after the $ClO_2$ spraying, respectively, which was over 86% reduction. There was no H2S detection. $NH_3$ concentration was around 420 ppm and less than 35 ppm before and after the $ClO_2$ spraying, respectively, which was over 83% reduction. $H_2S$ concentration was around 210 ppb and less than 32 ppb before and after the $ClO_2$ spraying, respectively, which was over 85% reduction. Hence, $ClO_2$ spraying at windowless barns was compost facility decreased malodor such as $NH_3$.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.236-236
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• 2017

Effluent treated by an NaDCC injection method in Ballast water management system (BWMS) contains reactive chlorine species and disinfection by-products (DBPs). In this study, we conducted whole effluent toxicity (WET) testing and ecological risk assessment (ERA) to investigate its ecotoxicological effects on marine environment. WET testing was carried out for four marine pelagic and freshwater organisms, i.e., diatom Skeletonema costatum, Navicula pellicuosa, chlorophyta Dunaliella tertiolecta, Pseudokirchneriella subcapitata, rotifer Brachionus plicatilis, Brachionus calyciflorus and fish Cyprinodon variegatus, Pimephales promelas. The biological toxicity test revealed that algae was the only biota that showed apparent toxicity to the effluent; it showed no observed effect concentration (NOEC), lowest observable effect concentration (LOEC) and effect concentration of 50% (EC50) values of 25-50%, 50-100% and >100%, respectively, at three water condition, but did not show any significant toxicities on other biota. Meanwhile, chemical analysis revealed that the BWMS effluent contained total residual oxidants (TROs) below $0.03{\mu}g/L$ and a total of 25 DBPs such as bromate, volatile halogenated organic compounds (VOCs), halogenated acetonitriles (HANs), halogenated acetic acids (HAAs), chloropicrin and Isocyanuric acid. Based on ERA, the 25 DBPs were not considered to have persistency, bioaccumulation and toxicity (PBT) properties. The ratio of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) of the other DBPs did not exceed 1 for General harbor environment. However, four substances (Isocyanuric acid, Tribromomethane, Chloropicrin and Monochloroacetic acid) were exceed 1 for Nearship environment. But observed toxicity in the test water on algal growth inhibition would be mitigated by normal dilution factor of 5 applied for nearship exposure. Thus, our results of WET testing and ERA showed that the BWMS effluent treated by NaDCC injection method would have no adverse impacts on marine environment.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.60-65
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• 2014

This study was conducted to investigate the antimicrobial effect of chlorine dioxide ($ClO_2$) on the vase life of cut rose 'Beast' (Rosa hybrida L.). Postharvest treatments to extend the vase life of cut roses were divided into two: holding solution treatment and pulsing solution treatment. In holding solution treatment, the cut roses were treated with preservative solutions containing tap water (TW, control), distilled water (DW), $ClO_2$ 2, 4, 6, and $8{\mu}L{\cdot}L^{-1}$, and compared with a commercialized antimicrobial compound of 8-HQS $200{\mu}L{\cdot}L^{-1}$. In pulsing solution treatment, cut roses were dipped into the $ClO_2$ solutions of 50, 100, 150, 200, and $250{\mu}L{\cdot}L^{-1}$ for 60 seconds and were placed in DW. The air temperature was $18.4^{\circ}C$, RH 51.5%, and light (photosynthetically active radiation, PAR) $3.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ with 12 hour day length. The longest vase life of cut roses was observed in the holding solution with $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ as 13.8 days and pulsing with $200-250{\mu}L{\cdot}L^{-1}$ as 13.5-13.7 days, where vase life were extended four days longer than TW. Whereas, the inclusion of 8-HQS $200{\mu}L{\cdot}L^{-1}$ in vase solution resulted in phytotoxicity. The relative fresh weight and water uptake have similar tendencies. Bacteria inhibition by $ClO_2$ and 8-HQS were very effective. But bacteria at TW and DW treatments on cut flower with stem were detected in $3.7{\times}10^5CFU{\cdot}L^{-1}$ and $6.3{\times}10^5CFU{\cdot}L^{-1}$, respectively (without stem in DW $1.4{\times}10^4CFU{\cdot}L^{-1}$). The $ClO_2$ contents in holding solution of all treatments were scavenged in two-four days after treatment. This study indicated that $ClO_2$ $4{\mu}L{\cdot}L^{-1}$ holding solution treatment and $200-250{\mu}L{\cdot}L^{-1}$ pulsing solution treatment can be applied to extend the postharvest life of cut roses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.138-145
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• 2010

The combined effect of 50 ppm aqueous chlorine dioxide ($ClO_2$) or 0.5% fumaric acid with $5 kJ/m^2$ ultraviolet-C (UV-C) on the postharvest quality of "Flamengo" strawberries was examined. After non-thermal treatment, the samples were stored at $4\pm1^{\circ}C$ for 12 days. The combined treatment of fumaric acid/UV-C reduced the initial populations of total aerobic bacteria and yeast and molds in the strawberries by 2.09 and 2.02 log CFU/g, respectively, compared to those of the control. In addition, after 12 days of storage the yeast and molds population in the combined treatment was 1.72 log CFU/g, compared to 5.10 log CFU/g for the control, resulting in a significant decrease of 3.38 log CFU/g. Postharvest treatments used in this study caused negligible changes in the color of the strawberries. Sensory evaluation results indicated that the combined postharvest treatment provided better sensory scores than did the control. In particular, the overall acceptability scores were higher for the combined treatment groups after 5 days of storage. These results suggest that combined treatment of either 50 ppm $ClO_2$ or 0.5% fumaric acid with $5 kJ/m^2$ UV-C can be useful for maintaining the quality of strawberries.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.365-369
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• 2007

This study was conducted to seek optimum concentration and treatment time of fermented rice water (Rizen) to disinfect food-borne bacteria in kitchen towel. $2.65\;log_{10}cfu/g$ of E. coli was reduced when double or triple diluted fermented rice water was treated during 2 hours. In case of concentrated fermented rice water, crude and double diluted solutions showed complete sterilization after 2 and 5 hours, respectively. On the other hand, triple, quadruple, quintuple diluted solutions needed 24 hours for complete sterilization. The effect of fermented rice water as a disinfectant was compared with water, detergent and chlorine treatment against E. coli and S. Typhimurium contaminated in kitchen towel. The initial number of E. coli in untreated kitchen towel were $5.0\;log_{10}cfu/g$ and were decreased to 4.32, 3.70 and 3.02 by treatments of water, detergent and chlorine, respectively. The double and triple diluted fermented rice water and double diluted concentrated fermented rice water also reduced the E. coli in kitchen towel to 2.43, 2.30 and $1.88\;log_{10}cfu/g$, respectively. The initial number of S. Typhimurium in untreated kitchen towel were $4.80\;log_{10}cfu/g$ and were decreased to 4.12, 3.58 and 2.81 by treatments of water, detergent and chlorine, respectively. The double and triple diluted fermented rice water and double diluted concentrated fermented rice water also reduced the E. coli in kitchen towel to 2.14, 2.03 and $1.59\;log_{10}cfu/g$, respectively. Consequently, the fermented rice water is thought to be a good disinfectant to reduce food-borne bacteria like E. coli and Salmonella contaminated in kitchen towel.