• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.31 no.2
• /
• pp.138-146
• /
• 2021

Objectives: This study aims to compare and evaluate the reduction efficiency of disinfectants used in the domestic meat processing industry to reduce bioaerosol exposure of meat industry workers and to use this as basic data for establishing work environment management measures. Methods: Thirteen disinfectants sold in South Korea were selected for evaluation and the bacterial reduction effect of the disinfectants was investigated. Bacterial suspension and surface disinfection tests were conducted to compare and analyze the antibacterial strength of the disinfectants. Pork carcasses, cutting boards, benches, and conveyor belts were selected for surface sterilization tests. Results: As a result of the bacterial suspension experiment test, all disinfectants had a bacterial reduction efficiency of more than 86%. Among them, the bacterial reduction efficiency of chlorine disinfectants was 99.93% on average. In the results of the pork carcass surface sterilization test, the rate of reduction of disinfectants made of quaternary ammonium compounds (QACs) was the highest. Tests of plastic cutting boards showed that chlorine disinfectants had the best sterilization effect. Experiments on stainless steel benches showed the best bacterial reduction efficiency for chlorine dioxide and QACs disinfectants. In the conveyor belt made of urethane, QACs disinfectants showed excellent sterilization effects. Conclusions: The study evaluated the disinfection power of disinfectants against bacteria occurring in domestic meat processing plants. All disinfectants were found to be effective in bacterial suspension experiments, and chlorine disinfectants were particularly effective. In surface sterilization experiments, sterilizing agents with QACs as the main ingredient were excellent.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.33 no.2
• /
• pp.100-104
• /
• 2013

Zoysiagrass (Zoysia japonica Steud.) is an important forage and turfgrass that spreads by stolons and rhizomes. Zoysiagrass stolon can be used directly for Agrobacterium-mediated genetic transformation by exploiting the potential of direct shoot formation. However, surface sterilization of field-grown stolons is difficult and remains to be explored. We developed an effective surface sterilization and culture method using the stolon explant for infection with Agrobacterium tumefaciens. Among various treatments, sequential disinfection in 30% bleach for 15 min followed by 0.1% mercuric chloride for 25 min resulted in the highest number of clean stolons. The efficacy of mercuric chloride was increased under vacuum conditions by incubating at 800 mbar for 5 min. The inclusion of 2.5 mg/l amphotericin B further prevents fungal growth in in vitro cultures. This protocol would speed up the development of transgenic plants by utilizing field-grown stolon nodes.

• Food Science and Preservation
• /
• v.10 no.1
• /
• pp.99-105
• /
• 2003

This study was carried out to investigate the efficacy of surface sterilization and the physicochemical properties of electrolyzed water manufactured from various electrolytic diaphragm and electrolyte. Physical properties of electrolyzed water manufactured from the diaphragm system were the most effective at the following conditions; the distance between diaphragms was 1.0 mm and the supplying rate of 20% NaCl was 6 mL/min. The ORP, HClO content and pH at above conditions were 1,170 mV, 100 ppm and 2.5, respectively. And two stage electrolyzed system was more effective than one stage electrolyzed water manufactured from non-diaphragm system, with 4 mL/min supplying rate of 20% NaCl, was similar to the most effective diaphragm system. But ORP, HClO content and pH were abut 800 mV, 200 ppm and 9 level, respectively. Sealed electrolyzed water could be preserved more than one month at room temperature with ORP of 750 mV in non-diaphragm system and 1,150 mV in diaphragm system, and HClO content of 100 ppm. Twelve kinds of microorganism tested were sterilized within 30 seconds from initial total counts of 10$\^$5/∼10$\^$6/cfu/ml by electrolyzed water. Though the ORP and HCIO contents of electrolyzed water manufactured from various electrolyte were higher in order of NaCl>KCl>CaCl$_2$, there were no difference between the electyolytes in the efficacy of sterilization. Salmonella typhi and Vibrio Proteolyticus were also sterilized by electrolyzed water manufactured from elctrolytes of NaCl CaC1$_2$and KCl

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.901-905
• /
• 2014

The efficacy of ozone micro-bubble water (OMBW) in reducing microbial populations on alfalfa seeds was investigated in this study. We observed the surface of alfalfa seeds using microscopy and found that many cracks and crevices existing on the surface could harbor pathogens. Alfalfa seeds were treated with tap water (TW), micro-bubble water (MBW), ozone water (OW), ozone micro-bubble water (OMBW), and chlorine water (CL) for 5 min, and total microbial population, E. coli and Salmonella spp. colonies were determined. Also, the sterilized seeds were germinated and cultivated for 5 d after sowing to investigate the percentage of germination and the growth of alfalfa sprouts. The treatments with OMBW and CL were most effective in reducing total microbial populations and E. coli was eliminated by OW, OMBW, and CL treatments. CL treatment reduced the percentage of germination and fresh weight of alfalfa sprouts, but OMBW did not cause any negative effects on the germination and growth of alfalfa sprouts. These results indicate that OMBW can be used as an effective sanitizer for eliminating seed-borne pathogens without detrimental effects on seed viability.

• Korean Journal of Food Science and Technology
• /
• v.36 no.3
• /
• pp.416-422
• /
• 2004

Efficacy of surface sterilization and physicochemical properties of electrolyzed water manufactured depending on electrolyte, materials, and type of electrolytic diaphragm used were investigated. Physical properties of electrolyzed water manufactured from diaphragm system showed the highest effectiveness under at distance between diaphragms of 1.0 mm and 20% NaCl supplying rate of 6 mL/min. ORP, HClO (should defined) content, and pH at above conditions were 1,170 mV, 100 ppm, and 2.5, respectively. Two-stage electrolyzed system was more effective than one-stage one. Electrolyzed water manufactured from non-diaphragm system at 4 mL/min supplying rate of 20% NaCl was similar to the most effective diaphragm system, whereas ORP, HClO content, and pH were 800 mV, 200 ppm, and 9, respectively. Sealed electrolyzed water could be preserved more than one month at room temperature with ORPs of 750 and 1,150 mV in non-diaphragm and diaphragm systems, respectively, and at HClO content of 100 ppm. Physicochemical properties of electrolyzed water manufactured from electrolytic diaphragm of $IrO_{2}$ and Pt+Ir were more effective than that of Pt. ORP and HClO contents of electrolyzed water manufactured from various electrolytes were high in order of NaCl>KCl>$CaCl_{2}$, whereas no differences were observed among electrolytes in sterilization efficacy. Twelve kinds of microorganisms tested (initial total count, $10^{5}-10^{6}CFU/mL$) were sterilized within 1-2 min by electrolyzed water.

• Korean Journal of Food Science and Technology
• /
• v.47 no.1
• /
• pp.81-86
• /
• 2015

Intense pulsed light (IPL), a nonthermal technology, has attracted increasing interest as a food processing technology. However, its efficacy in inactivating microorganisms has not been evaluated thoroughly. In this study, we investigated the influence of IPL treatment on the inactivation of Escherichia coli O157:H7 depending on light intensity, treatment time, and pulse number. Increased light intensity from 500 V to 1,000 V, raised the inactivation rate at room temperature. At 1000 V, the cell numbers were reduced by 7.1 log cycles within 120 s. In addition, increased pulse number or decreased distance between the light source and sample surface also led to an increase in the inactivation rate. IPL exposure caused a significant increase in the absorption at 260 nm of the suspending agent used in our experiments. This indicates that IPL-treated cells were damaged, consequently releasing intracellular materials. The growth of IPL-irradiated cells were delayed by about 5 h. The degree of damage to the cells after IPL treatment was confimed by transmission electron microscopy.

• Journal of Food Hygiene and Safety
• /
• v.26 no.3
• /
• pp.203-208
• /
• 2011

This study was to evaluate the efficacy of sanitizer concentrations and treatment time against two major toad-borne pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus on a stainless steel surface. As a result, stainless steel, treated with 100 ppm of chlorine showed reduction of E. coli(1.56, 1.49, 1.95 log cfu/25 $cm^2$) and S. aureus(0.49, 0.88, 1.27 log cfu/25 $cm^2$) after 0, 5 and 10 min, but none was not detected in treatment with 200 ppm. The population of E. coli(0.73, 0.90, 1.55 log cfu/25 $cm^2$) and S. aureus(0.37, 1.00, 1.45 log cfu/25 $cm^2$) reduced in 35.5% ethanol treated group, but none was not detected in treatment with 70%. The population was reduced E coli(0.28, 0.64, 1.07 cfu/25 $cm^2$) and S. aureus(0.53, 0.87, 0.99 log cfu/25 $cm^2$) by treatment with 45.5 ppm of hydrogen peroxide, but none was not detected in treatment with 91 ppm. Quarternary ammonium compound with 100 ppm was reduced E. coli(0.82, 1.62, 1.71 log cfu/25 $cm^2$) and S. aureus(0.46, 0.93, 1.38 log cfu/25 $cm^2$), but none was not detected in treatment with 200 ppm. Predictive models of sterilization for all 4 disinfectants were suitable to use with $r^2$ value of higher than 0.94. These models may be of use to food services and manufacture of safe products by controlling E. coli and S. aureus without the need for further detection of the organisms.