• 한국환경보건학회지
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• 제38권6호
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• pp.510-519
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• 2012

Objectives: This study was conducted in order to evaluate the microbiological contamination of the indoor air of the lunchrooms at child care centers and investigate the toxin genes and toxin production ability of food-borne pathogens. Methods: A total of 64 child care centers were sampled to test total aerobic bacteria, coliform bacteria, fungi, Staphylococcus aureus, Bacillus cereus and Salmonella spp. according to the Korea Food Code. All toxin genes of pathogens were detected using the Polymerase Chain Reaction method. The Sthaph. aureus enterotoxin was detected by a Staphylococcus aureus enterotoxin-reversed passive latex agglutination kit. The heamolysin BL (HBL) and non-heamolytic enterotoxin (NHE) produced by B. cereus were detected using a B. cereus enterotoxin-reversed passive latex agglutination kit and Bacillus diarrheal enterotoxin visual immunoassay kit, respectively. Results: The means of total aerobic bacteria and coliform bacteria were $1.91{\pm}1.84$ log CFU/plate and $0.47{\pm}0.62$ log CFU/plate, respectively. The mean of fungi also showed $0.59{\pm}0.71$ log CFU/plate. Among the pathogenic bacteria tested in this study, Staphy. aureus and B. cereus were detected in four (6.3%) and 21 (32.8%) out of 64 indoor air samples from lunchrooms in child care centers, respectively. All Staphy. aureus tested in this study possessed no toxin genes and did not produce enterotoxin. The detection rate of nheABC, hblCDA, entFM and ces toxin gene in B. cereus was 100, 57.1, 76.2 and 0%, respectively. B. cereus isolates were classified into four groups according to the presence or absence of toxin genes. The nheABC gene was the major toxin gene among B. cereus tested in this study. The HBL was detected in 11 out of 21 B. cereus isolates (52.4%) and three B. cereus isolates produced NHE (14.3%). Conclusion: The results indicated that the contamination by microorganisms in the indoor air of lunchrooms was unqualified to supply safe catering in child care centers. The ongoing control of indoor air quality is required.

• 한국식품위생안전성학회지
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• 제35권2호
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• pp.146-151
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• 2020

본 연구에서는 어린이집 급식실 실내공기와 급식테이블 및 조리종사자 손의 미생물학적 안전성을 평가하고자 하였다. 본 실험에서 사용된 재료는 어린이집 조리 종사자 24명의 손과 어린이집 18곳의 급식테이블 및 93곳의 실내공기를 실험대상으로 하였다. 조리 종사자 손의 미생물 채취는 Glove juice법, 급식테이블의 표면 미생물 채취는 Swab법에 따라 채취하였다. 어린이집 실내공기의 미생물 오염도는 자연 방치법에 따라 실험하였다. 조리 종사자 손의 일반세균 오염도는 평균 5.8±1.9 log CFU/hand로 나타났고, 대장균군 오염도는 평균 4.0±2.4 log CFU/hand로 나타났다. 급식테이블의 일반세균 오염도는 평균 4.3±3.0 log CFU/100 ㎠로 나타났고, 대장균군 오염도는 평균 2.6±3.3 log CFU/100 ㎠로 나타났다. 어린이집 조리 종사자 손과 급식테이블에서 B. cereus가 각각 2건씩 검출되었다. 실내공기 중 일반세균수 오염도는 평균 28±7.2 CFU/plate, 대장균군 오염도는 평균 3.1±2.9 CFU/plate로 나타났다. 또한, 실내공기 중 B. cereus 오염도는 평균 1.7±0.2 CFU/plate, S. aureus 오염도는 평균 1.6±0.5 CFU/plate로 나타났다. 이러한 결과를 종합해 볼 때, 어린이집 급식테이블 표면에 존재하는 미생물 오염도를 감소시키기 위한 식사 전 소독이 필요한 것으로 판단되었다. 또한, 실내공기 중 미생물 오염도 저감화를 위해 주기적인 환기와 급식 관계자들의 위생모, 마스크 및 위생복 등의 청결관리가 필요한 것으로 판단되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.96-99
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• 2003

The objective of this study was to evaluate the effects of various organic acids on microbial characteristics and Salmonella typhimurium in pork loins. Fresh pork loins were sprayed with various organic acids such as lactic acid, citric acid and acetic acid at various concentrations (0.5, 1, 1.5 and 2%). After spraying, the samples were packaged by HDPE film under air and stored at $4^{\circ}C$ for 14 days, and analyzed. Microbial deterioration of pork loins during the aerobic cold storage was delayed by organic acid spray. The bactericidal effect of acids increased with the increasing concentration. However, the inhibitory activity of organic acids during the storage varied with the kinds and concentrations of the acids. As for total plate counts, acetic acid was found to have the highest bactericidal activity, whereas citric acid was found to be the most inhibitory for coliform and S. typhimurium.

• 한국식품위생안전성학회지
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• 제34권4호
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• pp.361-366
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• 2019

본 연구에서는 다슬기 중의 자연균총의 정량적 오염도 분석과 해감 제거 공정(지하수, 상수)에 따른 저감화 효과를 조사하였다. 다슬기 중의 일반세균, 대장균군과 대장균, 진균 및 황색포도상구균의 정량적 검출을 위해 표준평판법을 사용하여 각각 plate count agar (PCA), potato dextrose agar (PDA), 대장균군/대장균용 3M Petrifilm 및 황색포도상구균용 3M Petrifilm에 도말하여 집락을 계수하였다. 지하수와 상수 처리에 따른 이들 균의 저감화 정도 역시 동일한 방법으로 수행되었다. 다슬기 원료 중의 미생물 오염도 분석시, 일반세균, 대장균군 및 진균은 각각 6.40, 2.70 및 $6.79{\log}_{10}CFU/g$로 조사되었다. 대장균과 황색포도상구균은 검출되지 않았다 (검출 한계: < $1{\log}_{10}CFU/g$). 그러나, 지하수로 해감 제거한 다슬기의 경우, 분석된 모든 미생물의 정량적 오염도가 원료 다슬기에 비해 높게 검출되었다. 특히 원료 다슬기에서 불검출이었던 대장균도 $2.46{\log}_{10}CFU/g$ 검출되었다. 상수로 해감 제거한 다슬기의 일반세균은 유의적으로 저감화 되지 않았으며(p<0.05), 대장균군은 유의적으로 증가하는 경향을 나타내었다(p>0.05). 진균만이 약간의 저감화(0.2 log 이하)를 유의적으로 보였다(p>0.05). 본 연구결과 지하수와 상수를 이용해서 해감 제거하는 공정만으로는 다슬기의 미생물학적 안전성을 확보하기 곤란한 것으로 판단된다.

• 한국환경보건학회지
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• 제38권6호
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• pp.568-574
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• 2012

Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.571-575
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• 2003

A marine aerobic Gram-negative bacterium, Pseudoalteromonas carrageenovora, has been blown to hydrolyze carrageenans, the sulfated galactans of red algae, and to desulfate oligo kappa-carrageenans. Recently, the gene encoding arylsulfatase (aryl-sulfate sulfohydrolase, E.C.3.1.6.1) of A. carrageenovora was cloned and the nucleotide sequence was reported. Enzymatic hydrolysis of sulfate groups in agaropectin simplifies the process of agarose preparation. In order to overproduce the enzyme, the arylsulfatase gene (astA, 984 bp ORF) from P. carrageenovora genome was amplified by PCR and subcloned into the pET21a vector. When the constructed plasmid pAST-A1 was introduced into E, coli BL21(DE3), the transformant on LB plate containing IPTG showed the hydrolyzing activity for p-nitrophenyl sulfate. Most of arylsulfatase activity was found in the cell lysate, but at $50\;{\sim}\;5000\;{\mu}M$ IPTG concentration the activity was found both in the culture supernatant and the cell lysate. The molecular weight of the recombinant enzyme was estimated to be 34 kDa by SDS-PAGE.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 1997년도 제18차 정기총회 및 학술발표회
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• pp.19-39
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• 1997

Extrusion conditions were optimized for blends of ground lamb and starch using a single-screw extruder for the purpose of producing expanded snack-type products. A central composite rotatable response surface methodology(RSM) design was used with variation in feed moisture, process temperature, and screw speed. The three variables significantly affected one or more of the measured physical properties of extrudates. The optimum conditions for minimum shear force values were 26.5% feed moisture, $148^{\circ}C$ process temperature, and 134 rpm screw speed. Lean ground beef, chicken, goat, lamb or mutton was blended with corn starch, and extruded at the optimum condition established from RSM experiments. Physical/rheological properties were generally similar, water activity was low (<0.12) and total aerobic plate counts were <10 for all products. Extrudates containing chicken had the highest ratio of polyunsaturated fatty acids to saturated fatty acids, whereas those containing beef had the highest ratio of monounsaturated fatty acids to saturated fatty acids. Sensory data indicated that texture was acceptable and flavor characteristics were not different among the products.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.174-176
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• 2003

A survey was conducted to investigate the sanitary condition of school kitchens in one region of Korea. A self-administered questionnaire recommended by the Korea Ministry of Education & Human Resources Development (MOEHRD) was offered to a random sample of dieticians of twenty-five elementary schools for food, sanitation and safety inspection of their kitchens. Air temperature, relative humidity, and airborne microbes in the kitchens were monitored during food preparation, processing and service. The inspection results showed their sanitary condition met the level B of the recommendation of the Korea MOEHRD. The range of air temperature of the kitchens was 21.4∼22.4$^{\circ}C$, and the range of relative humidity was 62.4∼69.6%. The microbiological evaluation of kitchen samples indicated aerobic plate count levels from 22.5 to 26.5 CFU/15 min. These results indicate that the levels of sanitary condition of kitchens in the schools were not satisfactory for safe foodservice although the inspection showed good results. This study suggests that the school kitchens should be monitored and strict inspection is necessary.

• 한국축산식품학회지
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• 제37권2호
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• pp.297-304
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• 2017

Animal-origin food products pose serious threat to public food safety due to high microbial loads. The microbial and radioactive contaminations in commercial cold duck meat products were evaluated. Ten different lots of commercial samples ($C_1-C_{10}$) were classified based on type and smoking process. All samples were highly contaminated (< 4-7 Log CFU/g) with total aerobic bacteria (TAB), yeasts and molds (Y&M), and 7 samples ($C_1-C_7$) were positive for coliforms. Furthermore, three samples were contaminated with Listeria monocytogenes ($C_4-C_6$) and one with Salmonella typhimurium ($C_6$). No radionuclides ($^{131}I$, $^{137}Cs$, and $^{134}Cs$) were detected in any sample. The results of DEFT (direct epifluorescent filter technique)/APC (aerobic plate count), employed to screen pre-pasteurization treatments of products, indicated that smoked samples were positive showing DEFT/APC ratios higher than 4. Notably, the samples showed a serious threat to microbial safety, thus were irradiated with electron-beam (e-beam). The $D_{10}$ values for S. typhimurium and L. monocytogenes were 0.65 and 0.42 kGy, respectively. E-beam application at 3 and 7 kGy resulted in reduction of initial TAB, Y&M, and coliform populations by 3 and 6 log cycles, respectively. Thus, e-beam was proven to be a good decontamination approach to improve the hygiene of cold duck meat.

• Asian-Australasian Journal of Animal Sciences
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• 제17권4호
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• pp.548-553
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• 2004

Patties were prepared using Barbari male goats meat (age about 4 yrs) and packed in HDPE under vacuum (VP) and aerobically (AP). Packed patties were stored at 4$\pm$1$^{\circ}C$ and evaluated for physico-chemical, microbiological and sensory changes on days 0, 5, 10, 15, 20 and 25. Overall mean water activity ($a_{w}$), moisture (%), fat (%), pH, TBA number and W-B shear force values (kg/$cm^{2}$) of patties were 0.983, 61.93, 18.39, 6.38, 0.150 and 0.86, respectively. Except pH that was significantly higher and TBA number significantly lower in VP patties, treatment had no significant (p>0.05) effect on other physico-chemical traits. However, storage period significantly (p<0.05) affected physico-chemical traits. Moisture (63.79%) and $a_{w}$ (0.985) were significantly (p<0.05) higher on day 25. Patties became firmer on day 20 onwards as indicated by higher W-B shear force. Though packaging method had no significant effect, storage period influenced microbial counts. The standard plate counts (SPC), which were initially log 5.98 CFU/g decreased significantly (p<0.05) on day 10 followed by steady increase and reaching log 4.89 on day 25. Almost similar trend was observed for psychrotrophic bacteria counts. Lactic acid bacteria counts declined as the storage period progressed. Coliforms, and yeast and mould counts were either not detected by the method used or were very low in numbers. All samples of AP patties revealed swollen, greasy and sticky surface with spongy texture on day 20 whereas only some of the VP patties shown such changes on day 20. Results indicated that vacuum packaging had definite advantage in preserving the sensory quality of patties than aerobic packaging but it did not help in extending the shelf-life beyond 15 days.