• The Korean Journal of Community Living Science
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• v.21 no.1
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• pp.13-18
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• 2010

This study was performed to investigate the antimicrobial effects of Euphorbia humifusa ethanol-extract against food-borne pathogens. The growth inhibitory effects of the extract at a concentration of 250, 500, 1,000 or 2,000 mg/L on food poisoning microorganism were determined against Salmonella typhimurium, Listeria monocytogenes, Yersinia enterocolitica, Escherichia coli O157:H7 and Staphylococcus aureus. The microorganisms growth was not affected by the extract at the concentration up to 250 mg/L, but was significantly (p<0.05) inhibited by the extract at a concentration higher than 1,000 mg/L. The extract of Euphorbia humifusa had strong antimicrobial activity against all test strains at a concentration of 2,000 mg/L. The results in the present study demonstrate antimicrobial effects of Euphorbia humifusa ethanol-extract against food-borne pathogens, suggesting that Euphorbia humifusa could be an effective natural antibacterial agent in food.

• Journal of Food Hygiene and Safety
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• v.21 no.1
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• pp.36-40
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• 2006

This study was conducted to investigate the effects of hot spring water against the survival of food-borne and pathogenic microorganisms. Staphylococcus aureus, Bacillus cereus, and Escherichia coli, which are food-borne microorganisms, Candida albicans and Trichophyton mentagrophytes, which are skin disease pathogens, and Helicobacter pylori, gastritis inducing microorganism, were tested. The content of fluoride in tested hot spring water is 14.1 mg/L, which is higher than the standard of safe for drinking water 1.5 mg/L, but the results on 48 other items were up to the standard. Hot spring water didn't show the bactericidal effects against food-borne microorganisms, C. albicans, and H. pylori tested. However, the viable cell populations of B. cereus and T. mentagrophytes were decreased, which were depends on the temperature of hot spring water. From these results, we confirmed that hot spring water didn't show the bactericidal effects against food-borne microorganisms, skin disease pathogens, and gastritis inducing microorganism, but the growth of some microorganisms were inhibited by high temperature ($41^{\circ}C$).

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.500-506
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• 2017

Kimchi cabbage is one of the four major vegetable crops in Korea. The total annual production of kimchi cabbage, the main material of kimchi, was 20,559 tons in 2015. Kimchi cabbage is one of the majer crops produced by farmers which accounts for about 80% of the total leaf vegetable production in Korea. As the consumption of environmental-friendly agricultural products increases, food safety is one of the major public health concerns. We analyzed the biological hazards of kimchi cabbage produced by two types of cultivation methos such as organic farming and conventional farming using various culture media and microscopy. A total of 432 samples were analysed for presence of sanitary indicator microorganisms (aerobic plate count, coliform count, yeast & mold) and food-borne pathogens (Staphylococcus aureus, environmental Listeria, Bacillus cereus). The population of sanitary indicating microorganisms and food borne pathogens was under 5 Log CFU/g in all tested samples. The results of total microorganism numbers of leaf surface showed a positive correlation to those of soil samples. Additionally, we examined chemical factors such as pesticide residues and heavy metals in soil samples. All tested samples did not shown contamination levels higher than the standard limit.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.222-227
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• 2017

This study aimed to explore the potential for food-industry application of atmospheric pressure dielectric barrier discharge plasma (atmospheric pressure DBD plasma) as a non-thermal sterilization technology for microorganism. The effects of the key parameters such as power, oxygen ratio, exposure time and distance on Escherichia coli KCCM 21052 sterilization by the atmospheric pressure DBD plasma treatment were investigated. The experimental results revealed that increasing the power, exposure time or oxygen ratio and decreasing the exposure distance led to an improvement in the sterilization efficiency of E. coli. Furthermore, the atmospheric pressure DBD plasma (1.0 kW power, 1.0% (v/v) $O_2$, 5 min exposure time and 20 mm exposure distance) treatment was very effective for the sterilization of food-borne pathogenic bacteria. The sterilization rate of E. coli, Bacillus cereus KCCM 40935, Bacillus subtilis KCCM 12027, Bacillus thuringiensis KCCM 11429 and Bacillus atrophaeus KCCM 11314 were 72.3%, 74.6%, 88.5%, 84.7% and 91.3%, respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2993-2998
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• 2009

An enzyme-linked immunosorbent assay (ELISA)-on-a-chip (EOC) biosensor combined with cell concentration technology based on immuno-magnetic separation (IMS) was investigated for use as a potential tool for early screening of Listeria monocytogenes (L. monocytogenes) in food products. The target analyte is a well-known pathogenic foodborne microorganism and outbreaks of the food poisoning typically occur due to contamination of normal food products. Thus, the aim of this study was to develop a rapid and reliable sensor that could be utilized on a daily basis to test food products for the presence of this pathogenic microorganism. The sensor was optimized to provide a high detection capability (e.g., 5.9 ${\times}\;10^3$ cells/mL) and, to eventually minimize cultivation time. The cell density was condensed using IMS prior to analysis. Since the concentration rate of IMS was greater than 100-fold, this combination resulted in a detection limit of 54 cells/mL. The EOC-IMS coupled analytical system was then applied to a real sample test of fish intestines. The system was able to detect L. monocytogenes at a concentration of 2.4 CFU/g after pre-enrichment for 6 h from the onset of cell cultivation. This may allow us to monitor the target analyte at a concentration less than 1 CFU/g within a 9 h-cultivation provided a doubling time of 40 min is typically maintained. Based on this estimation, the EOC-IMS system can screen and detect the presence of this microorganism in food products almost within working hours.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.198-205
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• 2008

In this study, microbial investigation is accomplished for 554 Jeot-kal samples(102 of Jeot-kal, 448 of Seasoned Jeot-kal and 4 of Sik-khe, respectively) that corresponds with Coliform-bacteria, Escherichia coli, Aerobic live bacteria as hygienic indicator microorganisms, and Staphylococcus aureus, Vibrio parahaemolyticus as Food-borne pathogenic microorganisms, Based on the methods in Korea Food Code, reliable data are obtained as follows; in 31.9% rate of the samples, Coliform bacteria are verified in the extent of $0{\sim}20,000$ CFU/g as 2.3 logCFU/g. Especially, Seasoned Jeot-kal(37.7%,2.3 logCFU/g) are detected to 6 and 2 folds higher than those of Jeot-kal, 5.9% and 1.4 logCFU/g. Likewise, Escherichia coli is detected from 9 samples only in Seasoned Jeot-kal, that includes seasoned squid, seasoned octopus, seasoned roe of pollack, seasoned large-eyed herring and seasoned hairtail. Aerobic live bacteria are also detected in the range of $0{\sim}8.9{\times}10^8CFU/g$. Against salinity, E. coli are detected in samples only less than 10% salinity. Concomitantly, aerobic live bacteria count is decreased to $5.5{\sim}3.6$ log CFU/g upon the salinity is increased up to 25%. However, S. aureus and V. parahaemolyticus are not detected in 554 samples, presumptively referring Jeot-kal products are somehow free from such food-borne pathogens. As the results above, we deliberately consider that the sanitary control in Jeot-kal, which be necessarily fermented- as well as non-microbially inactivated should be ensured in near future and also suggest an effectual microbial standard corresponding to the Negativity in E. coli for Jeot-kal products.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3578-3585
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• 2012

The purpose of this study was to establish the critical limit at CCP (Critical Control Point) of HACCP (Hazard Analysis Critical Control Point) system for instant noodle and it was conducted at P company in Ichen(Gyeonggi-do), Korea. According to the CCP, Fried process were experimented to removal and decrease of microbiological and chemical hazards by measuring of each temperature and times. As a result, the standard plate count and pathogenic microorganism were not detected by fried processing (Temperature : $145{\pm}10^{\circ}C$, Time : $75{\pm}30$ sec). The acid value of chemical hazards produced by fried processing was able to manage, showed lower (0.2) than the legal limit (0.6). Air-borne bacterial examination results detected(3 CFU/mL, 3 CFU/mL) in the Frying Room and Steam Room. Therefore, the CCP-BC of fried process would be a great alternative to prevent and remove hazard analysis, such as general and pathogenic microorganism (E. coli O157:H7, B. cereus, Listeria monocytogenes, Salmonella spp, Sthaph. aureus etc), chemical hazard analysis. In conclusion, it suggested that HACCP plan was necessary for management standard and systematic approach in establishement of critical limit, solving the problem, method of verification, education and records management by fried processing.

• Journal of Science Criminal Investigation
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• v.11 no.3
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• pp.210-217
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• 2017

In the forensic microbiology laboratories, microorganism analyses from food are requested. There have been several cases of Bacillus cereus isolated from the samples requested to the National Forensic Service. B. cereus is an important pathogenic bacterium which can cause food-borne outbreaks. Therefore, we isolated B. cereus from anchovy aekjeot recently requested for microbial examination and identified using MSId based on the 16S rDNA sequence and real-time PCR method. We also conducted PCR for detection of diarrheal toxin genes and an emetic toxin gene and found the presence of nheABC, bceT and entFM diarrheal toxin genes in the B. cereus isolate. There are several clinically important food-poisoning bacteria that should be noted during inspection. In particular, B. cereus can cause food poisoning even when cooked foods are ingested, because B. cereus forms endo-spore which confers strong environmental resistance and heat resistance to the bacteria, and the bacterial emetic toxin also has heat resistance. Here we highlight the importance to distinguish clinically important bacteria such as B. cereus from food specimens, and we expect this study will provide procedures for identification of B. cereus and detection of the bacterial toxin genes for future cases in the forensic microbiology laboratories.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.763-768
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• 2012

This study has been performed to measure the prevalence and microbial flora on chicken slaughtering as well as the processing process from the months of October to November. Whole-chicken rinsing technique was used in order to analyze the incidence of microorganisms on chicken carcass at the stage before chilling (after evisceration), after chilling and after cutting. The swab technique was used on processing the processed samples, such as working plates and cutting knives. Brine and cooling water from four cooling tubs were taken from each processing processes and were used as samples. Furthermore, the matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for whole cell fingerprinting in combination with a dedicated bioinformatic software tool was used to identify the isolated microorganisms. Of the tested samples and processes, brine ($4.50{\pm}0.64$ Log CFU/mL) and chicken carcass before chilling ($4.15{\pm}0.46$ Log CFU/mL) showed the highest population of microorganisms; the predominant microbial flora of them were Moellerella wisconsensis (54.84%), a member of the Enterobacteriaceae family, and Escherichia coli (60.36%), respectively. However, the predominant microbial flora of cut carcass was changed to Staphylococcus aureus (27.32%), which is a kind of pathogenic microorganism that can cause a food-borne illness. Therefore, the slaughtering and processing procedure of chicken are needed to be controlled more hygienically.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.192-199
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• 2010

The alone and combined effects of bacteriocin produced from Enterococcus faecalis MJ-213 and potassium sorbate against the food-borne pathogenic bacteria were studied. Bacteriocin minimal inhibitory concentration (MIC) values for Staphylococcus aureus ATCC 6538 and Salmonella enteritidis ATCC 13076 were 50 and 100 ${\mu}g$/ml, respectively. Bacteriocin (100 ${\mu}g$/ml) alone was active against S. aureus and S. enteritidis, but it was lower in antimicrobial effectiveness than the combination of bacteriocin (100 ${\mu}g$/ml) with potassium sorbate (100 ${\mu}g$/ml), which reduced initial counts (6 log cycle) of S. aureus and S. enteritidis by 1 and 3 log cycle, respectively. The bactericidal activity of bacteriocin of E. faecalis MJ-213 heated at $100^{\circ}C$ for 30 min or $121^{\circ}C$ for 15 min was markedly decreased as compared with the control. Moreover, the activity of bacteriocin was completely abolished by pepsin or protease II, but not affected by ${\alpha}$-amylase or lipase. The activity of bacteriocin adjusted to pH 6.0-8.0 showed almost the same inhibition ratio compared with the bacteriocin unadjusted pH, and though the inhibition ratio against pathogenic bacteria was reduced than the control, the bacteriocin was stable at pH 4.0 or 10.0, relatively. Furthermore, the combined treatment of bacteriocin and potassium sorbate than the alone treatment of bacteriocin significantly decreased (p<0.05) the viable cell counts of S. aureus or S. enteritidis inoculated on grind beef during storage at $4^{\circ}C$.