• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.366-374
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• 2012

Recently pathogenic E. coli is one of the main foodborne pathogens resulting in many patients in Korea. To understand the characteristics of pathogenic E. coli outbreaks in Korea, the epidemiological investigation reports of pathogenic E. coli outbreak in 2009 (41 reports) and in 2010 (27 reports) were collected in the web site of the Korea Centers for Disease Control and Prevention, reviewed and analysed in this study. The main places of the pathogenic E. coli outbreaks were food catering service area (64.8%) and restaurants (25.0%). The main type of the pathogens were EPEC (44.7%) and ETEC (34.2%). EAEC and EHEC was responsible for 10.5 and 9.2%, respectively. Eight of 68 outbreak cases were caused by more than 2 types of pathogenic E. coli which implicates the complicated contamination pathways of pathogenic E. coli. The incidence rate of pathogenic E. coli was $33.6{\pm}30.5%$ and the main symptoms were diarrhea, stomach ache, nausea, vomiting, and fever etc. The two identified food sources were identified as frozen hamburger pattie and squid-vegetable mixture. To improve the food source identification by epidemiological investigation, food poisoning notification to the agency should not be delayed, whole food items attributed the outbreak should be collected and detection method of the various pathogenic E. coli in food has to be improved. In conclusion, the characteristics between the EHEC outbreaks in the western countries and the EPEC or ETEC outbreaks in Korea needs to be distinguished to prepare food safety management plan. In addition, the development of the trace back system to find the contamination pathway with the improved detection method in food and systemic and cooperative support by the related agencies are necessary.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.466-472
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• 2012

In this study, ribulose bisphosphate carboxylase (rbcL), RNApolymeraseC (rpoC1), intergenic spacer (psbA-trnH), and second internal transcribed spacer (ITS2) as identification markers for discrimination of P. mirifica in foods were selected. To be primer design, we obtained 719 bp, 520 bp, 348 bp, and 507 bp amplicon using universal primers from selected regions of P. mirifica. The regions of rbcL, rpoC1, and psbA-trnH were not proper for design primers because of high homology about P. mirifica, P. lobata, and B. superba. But, we had designed 4 pairs of oligonucleotide primers from ITS2 gene. Predicted amplicon from P. mirifica were obtained 137 bp and 216 bp using finally designed primers SFI12-miri-6F/SFI12-miri-7R and SFI12-miri-6F/SFI12-miri-8R, respectively. The species-specific primers distinguished P. mirifica from related species were able to apply food materials and processed foods. The developed PCR method would be applicable to food safety management for illegally distributed products in markets and internet shopping malls.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.131-140
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• 2014

The objective of this study was to develop a simultaneous method of 8 penicillin antibiotics including amoxicillin, ampicillin, cloxacillin, dicloxacillin, nafcillin, oxacillin, penicillin G and penicillin V in meat using LC-MS/MS. The procedure involves solid phase extraction with HLB cartridge and subsequent analysis by LC-MS/MS. To optimize MS analytical condition of 8 compounds, each parameter was established by multiple reaction monitoring in positive ion mode. The chromatographic separation was achieved on a $C_{18}$ column with a mobile phase of 0.05% formic acid and 0.05% formic acid in acetonitrile at a flow rate of 0.2 mL/min for 20 min with a gradient elution. The developed method was validated for specificity, linearity, accuracy and precision in beef, pork and chicken. The recoveries were 71.0~106%, and relative standard deviations (RSD) were 4.0~11.2%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.003~0.008 mg/kg and 0.01~0.03 mg/kg, respectively, that are below maximum residue limit (MRL) of the penicillins. This study also performed survey of residual penicillin antibiotics for 193 samples of beef, pork and chicken collected from 9 cities in Korea. Penicillins were not found in all the samples except a sample of pork which contained cloxacillin (concentration of 0.08 mg/kg) below the MRL (0.3 mg/kg).

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.123-130
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• 2014

A simultaneous determination was developed for 9 aminoglycoside antibiotics (amikacin, apramycin, dihydrostreptomycin, gentamicin, hygromycin B, kanamycin, neomycin, spectinomycin, and streptomycin) in meat by liquid chromatography tandem mass spectrometry (LC-MS/MS). Each parameter was established by multiple reaction monitoring in positive ion mode. The developed method was validated for specificity, linearity, accuracy, and precision based on CODEX validation guideline. Linearity was over 0.98 with calibration curves of the mixed standards. Recovery of 9 aminoglycosides ranged on 60.5~114% for beef, 60.1~112% for pork and 63.8~131% for chicken. The limit of detection (LOD) and limit of quantification (LOQ) were 0.001~0.009 mg/kg and 0.006~0.03 mg/kg, respectively in livestock products including beef, pork and chicken. This study also performed survey of residual aminoglycoside antibiotics for 193 samples of beef, pork and chicken collected from 9 cities in Korea. Aminoglycosides were not found in any of the samples.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.99-104
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• 2014

This study was done to analyze the contents of minerals and to investigate the ratio of measured values to labeled values and to analyze the ratio of calcium to other minerals in 68 specimen with minerals - fortified commercial beverages, noodles, cereals and grain products. Content of calcium, iron and zinc in samples after microwave digestion was analyzed with an ICP-OES. The measured values of calcium were ranged 82.2~293.1% of the labeled values in 38 samples composed calcium - fortified commercial beverages, noodles, cereals and grain products. The measured values of iron and zinc were ranged 83.3~301.0%, 90.1~314.1% of the labeled values in minerals - fortified commercial beverages, noodles, cereals and grain products, 42, 24 samples. The Ca : Fe ratios were 90.55 (50.55~220.64) in fruit & vegetable juice, 850.41 in fruit & vegetable beverage, 553.49 in blended beverage, 179.07 (118.37~238.01) in soy milk, 204.39(41.64~397.52) in noodle, 296.97(121.64~868.88) in fried noodle, 30.89(15.69~62.05) in cereal and 7.73(0.22~49.92) in grain product. The Ca : P ratios were 1.44(0.96~1.98) in fruit & vegetable juice, 1.92 in fruit & vegetable beverage, 1.66 in blended beverage, 4.23(2.25~7.72) in soy milk, 1.14(0.28~1.97) in noodle, 1.88(1.17~2.42) in fried noodle, 1.29(0.87~2.92) in cereal and 0.30(0.06~1.57) in grain product. The Ca : Mg ratios were 1.85(0.87~5.04) in fruit & vegetable juice, 28.72 in fruit & vegetable beverage, 2.97 in blended beverage, 5.27(2.93~9.36) in soy milk, 3.97(1.34~7.57) in noodle, 6.77(4.63~10.78) in fried noodle, 4.40(2.30~12.55) in cereal and 1.17(0.23~7.48) in grain product. These results suggest calcium contents and the ratio of calcium contents to other minerals in calcium-fortified food products should be strictly controlled. Moreover, to avoid problems with Excessive nutrition, there must be initiatives for better understanding on food labelling and nutrition for fortified food.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.158-163
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• 2014

In this study, two commercial PCR and ELISA test kits were examined for identification of eight animal species (beef, pork, chicken, duck, turkey, goat, lamb, and horse) from raw meat and meat products in Korea. The detection limit in RAW meat ELISA kit$^{(R)}$ on three types of meat samples blended with beef, pork and chicken, demonstrated that all meat species were differentiable down to 0.2%. RAW meat ELISA kit$^{(R)}$ on animal species resulted in differentiation rate of 94.5% for beef, 93.3% for pork, 90% for lamb, and 100% for chicken, duck, turkey, goat, and horse. In contrast, Powercheck Animal Species ID PCR kit$^{TM}$ resulted in 100% specificity at 0.05% limit of detection for all meat species. The detection limit of Cooked Meat ELISA kit$^{(R)}$ on mixed meat samples heat-treated with different temperatures and times, resulted in 0.1% for all heat-treated mixed meat except for chicken at 1.0%. Additionally, ELISA kit on sixty meat products resulted in specificity of 31.8% for ham, 13.6% for sausages, and 12.5% for ground processed products, and relatively low rate for more than 2 types of mixed meats. On the contrary, meat species differentiation using PCR kit showed higher percentage than that using ELISA kit$^{(R)}$: 50.0% for ham, 41.7% for sausages, and 28.6% for ground processed meat. Futhermore, PCR kit on 54 dried beef meats detected pork genes in 13 products whereas ELISA kit showed negative results for all products. Hence, the possibility of cross-contamination during manufacturing process was investigated, and it was found that identical tumblers, straining trays, cutters and dryers were used in both beef and pork jerky production line, suggesting the inclusion of pork genes in beef products due to cross-contamination. In this study, PCR and ELISA test kits were found to be excellent methods for meat species differentiation in raw meat and heat-processed mixed meat. However, lower differentiation rate demonstrated in case of meat processed products raised the possibility of inclusion of other species due to cross-contamination during manufacturing process.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.334-339
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• 2014

The purpose of our study was to investigate the migration level of lead (Pb), cadmium (Cd), antimony (Sb), arsenic (As), hexavalent chromium ($Cr^{6+}$) and mercury (Hg) from cookwares into food simulants and to evaluate the safety of each heavy metals. The test articles for heavy metals were glassware, ceramics, enamel, earthenware, polypropylene and polyethylene cookwares for Pb and Cd, enamel for Sb, earthenware for As, polyethylene and polypropylene cookwares for $Cr^{6+}$ and Hg. All the article samples of 391 intended for contact with foods were purchased in domestic markets. Pb, Cd, Sb and As were analyzed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), $Cr^{6+}$ by UV visible spectrophotometer and Hg by mercury analyzer. The migration levels of heavy metals in all the samples were within the migration limits of Ministry of Food and Drug Safety (MFDS). As a result of safety evaluation, our results showed that the estimated daily intakes (EDI, mg/kg bw/day) were $9.12{\times}10^{-6}$ and $8.83{\times}10^{-7}$ for Pb and Cd from ceramics and $1.19{\times}10^{-5}$, $1.23{\times}10^{-5}$ and $7.52{\times}10^{-6}$ for Pb, Cd and Sb from enamel. Tolerable daily intakes (TDI, mg/kg bw/day) were established respectively as 0.0036, 0.00081, 0.0021, and 0.0006 for Pb, Cd, As and Hg by JECFA (Joint FAO/WHO Expert Committee on Food Additives), as 0.0060 for Sb by WHO (World Health Organization). When comparing with TDIs, the EDIs accounted for 0.25% and 0.11% for Pb and Cd from ceramics and 0.33%, 1.52% and 0.13% for Pb, Cd and Sb from enamel.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.102-109
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• 2018

In the present study, a variety of polylactide (PLA) articles (n = 211) were tested for migration of lead (Pb), cadmium (Cd) and arsenic (As) into the food simulant (4% v/v acetic acid). Pb, Cd, and As were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Migration tests were performed at $70^{\circ}C$ and $100^{\circ}C$ for 30 min. The amounts of Pb, Cd, and As increased at $100^{\circ}C$ for 30 min compared with levels at $70^{\circ}C$. However, the migration at both conditions was very low. The maximum level of Pb at $100^{\circ}C$ for 30 min corresponded to 1% of the migration limit. The estimated daily intakes (EDI) based on safety evaluation ranged from $2.5{\times}10^{-5}$ to $2.0{\times}10^{-3}{\mu}g/kg\;bw/day$ for Pb, Cd, and As. The EDI calculated from migration of Pb at $100^{\circ}C$ for 30 min in PLA was the maximum value, $2.0{\times}10^{-3}{\mu}g/kg\;bw/day$, which corresponded to 0.055% of provisional tolerable weekly intake (PTWI, $25{\mu}g/kg\;bw/week$). The data from this study represent a valuable source for science-based safety control and management of hazardous heavy metals migrating from polylactide food contact materials.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.634-643
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• 2012

Job stress is emerging as one of major issues related to oral health in modern society that has increasingly been complicated and diversified. The purpose of this study was to examine the job stress and dry mouth of workers and their self-diagnosed oral symptoms in an attempt to determine the relationship between job stress and dry mouth. The subjects in this study were 366 workers, and a survey was conducted to June 1 to 20, 2012. Whether there would be any differences in dry mouth and self-diagnosed oral symptoms according to job stress was analyzed, and it's found that there were significant differences in dry mouth according to organizational climate. And oral symptoms made significant differences to job demand, interpersonal conflicts, organizational system, lack of reward and job stress. There was a positive correlation between dry mouth and organizational climate, and oral symptoms had a significant correlation to job demand, interpersonal conflicts, job insecurity, organizational system, job stress and dry mouth. Organizational climate and lack of reward had a significant impact on dry mouth, and oral symptoms were under the significant influence of dry mouth, job insecurity and organizational system.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.169-179
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• 2009

This study aims to present a fundamental data base to figure out the mental and the physical conditions that the dental technicians are facing and ultimately to develop a health care program to deal with their health related problems. To this end, we took an analysis on the health status among the subjects of 895 dental technicians currently working at the dental lab around the nation from January 15 to March 31, 2009 by way or Todai Health Index(THI). Of the average scale point in accordance with 12 scale scores of the physical and the mental subjective symptom, the results revealed that the physical appeals (21.10) were higher than the mental appeals (18.49) and the multiple subjective symptom was marked as 38.44 followed by the mental irritability (25.92). In gender differences, the females proved to be higher than the males in both physical appeals and mental appeals while the physical appeals were dominant in both genders. The physical appeals were higher than the mental appeals with regard to the general characteristics. In the case or the group or age twenties as shown in the physical and mental average scale point, the other groups showed 21.55% of the physical appeals among the married whereas the mental appeals showed the highest point as 18.70 in the unmarried group. In job position, the other groups marked the highest, in working condition, below average group marked the highest, in frequency of break time, none group marked the highest. We drew a conclusion form this study that the dental technicians gained the higher points in the item or the multiple subjective symptom, the menial irritability, and the irregular life. More research on th is phenomena should be followed along with the development of various and practical health care programs to promote the health or dental technicians.