• YAKHAK HOEJI
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• v.60 no.1
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• pp.1-7
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• 2016

The aim of this study was to investigate the prevalence of quinolone resistant E. coli from retail meat and to characterize the resistant determinants. Determination of minimum inhibitory concentration, the sequence analysis of gyrA, gyrB, parC, and parE quinolone resistance determining regions (QRDR), the presences of plasmid mediated quinolone resistance (PMQR) and the expression of efflux pump genes were investigated. Of the total 277 retail meat samples, 67 coli form bacteria were isolated. 15 of 67 isolates showed nalidixic acid resistance and 7 of 15 nalidixic acid resistant isolates were also resistant to ciprofloxacin, moxifloxacin and levofloxacin. 11 of 15 nalidixic acid resistant strains were isolated from chicken, 2 of 15 were isolated from beef and 2 of 15 were isolated from pork samples. 11 of 15 nalidixic acid resistant strains have single mutation at codon 87 (D87N or D87G) in gyrA, 2 of 11 gyrA mutants have double mutations at codon 86 and 87 (L86A and L87I) in parC with mutations at codon 434+445+465 or 429 in gyrB. 2 of 15 resistant isolates harbored qnrS, a PMQR determinant. Over expression of the acrB gene, efflux pump gene (3.93~16.53 fold), was observed in 10 of 15 resistant isolates.

• Journal of the Korean Dietetic Association
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• v.18 no.4
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• pp.372-384
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• 2012

The purpose of this study was to provide a basic resource for establishment of hygienic management standards for meal delivery from the central kitchen to schools. Flow diagrams for delivery of food were analyzed, and time-temperature conditions of the food and environment were measured. Four different foods samples including Mexican salad, radish salad, stir-fried pork and vegetables, and stir-fried chicken and vegetables were collected after production and before service. Microbiological analysis was performed for aerobic plate counts (APC), Enterobacteriaceae, coliforms, E. coli, Salmonella spp., S. aureus, B. cereus, C. perfringens, and L. monocytogenes. After completion of production of cooked foods 2~3 hours were taken for the cooked foods to reach the temperature danger zone. Food temperatures at the meal service did not meet the recommended temperatures ($10/57^{\circ}C$) for conventional school food service systems. The highest APC counts were observed in radish salad (5.70 log CFU/g), followed by Mexican salad (5.18 log CFU/g). Enterobacteriaceae and coliform counts were within acceptable levels of those recommended by the UK Public Health Laboratory Service. No E. coli or pathogens were found. These results provide useful information for determination of microbiological hazards in school food service systems, and suggest that time-temperature control during delivery is necessary for the safety of cooked foods.

• 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.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.541-550
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• 1996

Tetracycline antibiotics have been widely used not only therapeutics but feed additives. There are many methods for the isolation and determination of tetracycline antibiotics in animal muscle tissue. But those methods take much time and labor, so it is difficult to analyse many samples simultaneously. A rapid isolation method and liquid chromatographic determination of tetracycline antibiotics in animal muscle tissue (bovine, porcine, chicken) is presented. Blank control and tetracyclines fortified samples (0.5g) were blended with $C_{18}$ containing 0.05g each of oxalic acid and disodium ethylenediaminetetraacetate. After homogenize, homogenate was transferred to glass column made from 10ml glass syringe and compressed to 4~4.5ml volume. A column made from the $C_{18}$/meat matrix was washed with hexane (8ml) and dichloromethane (8ml, if needed), following which the tetracyclines were eluted,vith methanol or 0.01M methanolic oxalic acid (8ml). The eluates containing tetracyclines analytes were free from interfering compounds when analysed by HPLC with UV detection (photodiode array at 360nm). Standard curve for each tetracycline showed a linear response at the range of $0.05{\sim}1.0{\mu}g/ml$ and tetracycline antibiotics were eluted within 4ml of eluted volume. All tetracycline antibiotics except tetracycline were stable during the concentration process at $40^{\circ}C$ and time required for concentration was 3~4 hours. Fortified samples containing oxalic aicd and EDTA represented more good recoveries than those of not-contained sample. Recoveries were 91.8~110.1% (oxytetracycline; OTC), 57.7~79.5% (tetracycline; TC), 78.1~88.6% (chlortetracyclines; CTC) and 88.4~100.6% (doxycycline; DC) in pork tissue, 101.1~126.8% (OTC), 66.4~75.4% (TC), 79.2~88.1% (CTC) and 69.3~86.7% (DC) in beef tissue, and 90.8~95.6% (OTC), 66.2~84.4% (TC), 75.7~77.2% (CTC) and 55.6~80.7% (DC) in chicken muscle tissue. The detection limits validated in muscle tissue by this method were $0.05{\mu}g/g$ for OTC and TC, and $0.1{\mu}g/g$ for CTC and DC.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.1109-1119
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• 2018

In this paper, we report the development of a nondestructive prediction model for lean meat percentage (LMP) in Korean pig carcasses and in the major cuts using a machine vision technique. A popular vision system in the meat industry, the VCS2000 was installed in a modern Korean slaughterhouse, and the images of half carcasses were captured using three cameras from 175 selected pork carcasses (86 castrated males and 89 females). The imaged carcasses were divided into calibration (n=135) and validation (n=39) sets and a multilinear regression (MLR) analysis was utilized to develop the prediction equation from the calibration set. The efficiency of the prediction equation was then evaluated by an independent validation set. We found that the prediction equation - developed to estimate LMP in whole carcasses based on six variables - was characterized by a coefficient of determination ($R^2_v$) value of 0.77 (root-mean square error [RMSEV] of 2.12%). In addition, the predicted LMP values for the major cuts: ham, belly, and shoulder exhibited $R^2_v$ values${\geq}0.8$ (0.73 for loin parts) with low RMSEV values. However, lower accuracy ($R^2_v=0.67$) was achieved for tenderloin cuts. These results indicate that the LMP in Korean pig carcasses and major cuts can be predicted successfully using the VCS2000-based prediction equation developed here. The ultimate advantages of this technique are compatibility and speed, as the VCS2000 imaging system can be installed in any slaughterhouse with minor modifications to facilitate the on-line and real-time prediction of LMP in pig carcasses.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.127-131
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• 2007

In order to investigate the presence of pathogenic bacteria in fresh pig loin and the growth changes of microorganism in raw ham during storage at 10 and $25^{\circ}C$. These hams were manufactured according to a short-ripening procedure being completed in 4 weeks with dry-curing followed by wet-curing and ripening. The result regarding the contamination level of microorganism in the fresh raw pig loin showed that the count of total aerobes was $3.11\;log\;CFU/cm^2$, and the population of lactic acid bacteria, Pseudomonas spp., Clostridium spp., and yeast and mould had not risen over $2\;log\;CFU/cm^2$ on the storage time. However, the average count ofEnterobacteriaceae in pork loin was $3.11\;log\;CFU/cm^2$, which represented the predominant species. The pathogenic bacteria including Salmonella spp, Staphylococcus aureus, Vibrio parahaemolyticus, Clostridium perfringene, Listeria monocytogenes, and Escherichia coli O157:H7 were not detected either in fresh pork loin or in raw ham products stored at 10 and $25^{\circ}C$. The initial count of total aerobes in raw ham samples was 3.06 log CFU/g, and increased slightly after 90 days at 10 and $25^{\circ}C$ to 4.6 and 4.69 log CFU/g, respectively. The predominant species in raw ham products during storage time were lactic acid bacteria and Staphylococcus spp.

• Analytical Science and Technology
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• v.18 no.3
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• pp.250-256
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• 2005

A selective method of high performance liquid chromatography with UV detector has been applied to determine 4 tetracycline antibiotics in the animal food, simultaneously. The targets were chlortetracycline (CTC), doxycycline (DC), oxytetracycline (OTC), and tetracycline (TC) that are used routinely in veterinary medicine for prevention and control of disease. Food samples were beef, pork, chicken, milk, whole egg, flatfish (Limanda yokohamae), jacopever (Sebastes hubbsi), seabream (Chrysophrys major), eel (Anguilla japonica) and lobster (Hommarus americanus). After extracting food samples with 20% trichloroacetic acid and McIlvaine buffer, they were purified by a $C_18$ SPE cartridge with 0.01M methanolic oxalic acid solution. The concentrated residue was re-dissolved in methanol, filtered, cleaned up and analyzed on a $C_18$ column. The mobile phase was a mixture of 0.01M oxalic acid and acetonitrile with a gradient ratio from 85:15 to 60:40. The UV wavelength was 365 nm. The overall recoveries were ranged from 71% to 98% and the limit of detections were 0.022 for CTC, 0.012 for DC and OTC and 0.009 mg/kg for TC at signal/noise > 3, respectively. As results, CTC, DC and TC were not detected in all selected food samples, however, OTC was detected in meat and fishes. The determined level of OTC was 0.04 ppm for pork, 0.17 ppm for flatfish and 0.05 and 0.08 ppm for jacopever, that were within the Maximum Residue Limits (MRLs) in the food.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.684-688
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• 2010

Biodiesel produced from the reaction of methanol and triglyceride which is the main component of animal fats and vegetable oils is known for remarkable lubricity. In this study, the lubricity of 3 kinds of biodiesel came from vegetable oils such as soybean oil, palm oil, and perilla oil and 2 kind of biodiesel which were produced from beef tallow and pork lard were analyzed using HFRR (High frequency reciprocating rig). In HFRR test result, the lubricity of perilla and soybean's biodiesel was higher than other biodiesels. After analysis of biodiesel components by GC-MS and determination of the lubricity of pure biodiesel components using HFRR, it was found that a higher olefin content and long alkyl chaining biodiesel had an excellent lubricity property.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.607-615
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• 2005

The purpose of this study was to analyze the characteristics of Chinese foods in main ingredients, sauces, and cooking methods, and to assess the applicability of kochujang in Chinese foods. Twenty Chinese foods and commercial kochujang were selected by a Chinese head cook. The main ingredients were 24 kinds such as pork, chicken, shrimp, bok choy, bean curd, Chinese noodles etc., which were generally used in Korean foods. The main Chinese sauces were 11 kinds, and soy sauce was used in 12 foods, shang loo tau soy sauce in 2, wine in 8, oyster sauce in 7, rice wine in 6. The classification of cooking units in all Chinese foods was performed and the cooking frequency was deep frying>pan frying>boiling>stir frying>steaming>roasting. The proper amount of kochujang (weight ratio) was decided by pre-test of the Chinese head cook and Chinese food added kochujang was assessed by a Chinese focus group. The overall preference of Chinese food added kochujang was assessed highly and was related to the kinds of sauces, and to the kinds of main ingredients. The foods which used soy sauce or shang loa tau soy sauce were preferred. Sweetness by using kochujang wasn't preferred in several foods. Saltiness and aftertaste by using kochujang didn't affect the food preference, and the intensity of color and pungency were evaluated as a moderate level. An increased amount of kochujang would be possible in several foods. However, the increase in the amount of kochujang for intensive color and pungency in Chinese foods was directly related to the increase of sweetness, which had been discussed as the main problem in lowering the preference. Therefore, the screening of various Chinese foods harmonized with kochujang and the determination of the proper mixing ratio with Chinese sauces are very important. The results of this study could be used as basic data for the promotion of kochujang consumption in the Chinese market.

• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.299-302
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• 2010

This study was conducted to determine the content of heavy metals in meats available on the Korean markets. Trace metals (Pb, As and Cd) were detected in 4 kinds, 172 samples by inductively coupled plasma-mass spectrometry (ICP-MS). The values of heavy metals in meats were as follows; In beef, mean (minimum~maximum) values of the heavy metals were Pb: 0.075 (0.020~0.190)mg/kg, As: 0.010 (0.001~0.050)mg/kg and Cd: 0.43(0.07~2.11)${\mu}g/kg$. In pork, mean (minimum~maximum) values of the heavy metals were Pb: 0.065 (0.012~0.171)mg/kg, As: 0.004 (ND~0.021)mg/kg and Cd: 0.43(0.08~1.09)${\mu}g/kg$. In chiken, mean (minimum~maximum) values of the heavy metals were Pb: 0.060(0.016~0.211)mg/kg, As: 0.008 (ND~0.042)mg/kg and Cd: 0.42 (0.02~3.80)${\mu}g/kg$. In duck, mean (minimum~maximum) values of the heavy metals were Pb: 0.070 (0.011~0.157)mg/kg, As: 0.005 (0.001~0.011)mg/kg and Cd: 0.87 (0.15~3.75)${\mu}g/kg$. This results will be used as a basic data for the future legislation on the regulation and control of heavy metal in meats.