• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1353-1358
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• 2005

A rapid and quantitative real-time PCR was developed to target the invasion A (invA) gene of Salmonella spp. We developed quantitative standard curves based on plasmids containing the invA gene. Based on these curves, we detected Salmonella spp. in artificially contaminated buffered peptone water (BPW) and milk samples. We were able to determine the invA gene copy number per ml of food samples, with the minimum detection limit of $4.1{\times}10^{3}$ copies/ml of BPW and $3.3{\times}10^{3}$ copies/ml of milk. When applied directly to detect and quantify Salmonella spp. in BPW and milk, the present real-time PCR assay was as sensitive as the plate count method; however, copy numbers were one to two logs higher than the colony-forming units obtained by the plate count methods. In the present work, the real-time PCR assay was shown to significantly reduce the total time necessary for the detection of Salmonella spp. in foods and to provide an important model for other foodborne pathogens.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1453-1458
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• 2008

For quantitative PCR assay of Salmonella enterica serovar Typhimurium in food samples, a real-time PCR method was developed, based on DNA genome equivalent. Specific primers and probe designed based on the STM4497 gene of S. Typhimurium LT2 showed the specificity to S. Typhimurium. Threshold cycle (Ct) values of real-time PCR were obtained from a quantitative standard curve with genomic DNA of Salmonella Typhimurium. In addition, the recovery of S. Typhimurium inoculated artificially to chicken samples with $4.5{\times}10^5$ to 4.5 CFU/ml was evaluated by using real-time PCR and plate-count methods. Result showed that the number of cells calculated from the real-time PCR method had good correlation with that of the plate-count method. This real-time PCR method could be applicable to the detection and quantification of S. Typhimurium in food samples.

• 한국조리학회지
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• 제7권3호
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• pp.85-98
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• 2001

This study was performed to describe the overall sanitation of baking utensils and equipments, employees, and environment in 9 bakeries. Microbiological tests on employees, utensils and equipments, were done according to standard procedure and included total plate count, coliforms, fungi and Staphylococcus aureus.. Microbiological testing is a value in determining hazards for developing a HACCP plan but were not detected throat and employee's hands before use. Staphylococcus aureus was detected nasal cavity and employees's hands after use. Employee's apron after use was detected fungi and coliform and was risk factor of cross-contamination to bread or cookies et al. Generally hygienic conditions of pan, kitchen board, knife, brush, and wooden scoop were worse than those of other baking utensils such as tray, bread tweezers, dusting brush and dish cloth. And refrigerator, freezer and fermentation chamber were detected fungi and coliforms. Total plate count of heating table, working table, distribution table, washbowl and refrigerator was increased in 2nd period. Temperature of refrigerator was 10.43$^{\circ}C$ and strict temperature control of refrigerations needs. Therefore, baking utensils and equipments were reguraly need to sterilize and clean. Additionary, it need to practice the effective sanitation education and training program for the bakery managers and employees.

• 한국환경보건학회지
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• 제21권1호
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• pp.7-20
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• 1995

The aims of this study are to enhance the students' knowledge of the drinking water and its reliability by investigating drinking water situation on the drinking water. The results are as following 1. Status and drinking behavior about school drinking water (1) 97.82% of the schools are using the tap water as the resource of drinking water. (2) 46 schools are in possession of water tank and 18 schools of them are using the water tank as the resource of drinking water. The clearing and sanitization of the tank are carried out once in a year with hypochloronatrium by the low-level officials. (3) 51.28% of the schools are providing the students with drinking water and 75% of them with boiled water. The drinking water supply managers are low-level officials, nurse teachers, and dietitian. 2. Analysis of the drinking water quality (1) Most of the drinking water provided by the school are tap water 35.8%, barely tea 5.85%, filtered water 6.3%, ground water 1.1% and all turned out to be suitable for drinking. (2) The drinking water carried from home turned out to be unsuitable for drinking except pH criterion, especially the test of APC(Aerobic Plate Count) and Coliform group showed worse degree. These results were caused by the hygiene problem and maltreatment in water container.

• 동아시아식생활학회지
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• 제10권6호
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• pp.507-513
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• 2000

This study was conducted to investigate the shelf life of beef stored in antimicrobial pottery during 12days storage at 4'C and Five kinds of antimicrobial potteries were prepared with antimicrobial materials such as TiO$_2$, Ag (NO$_3$)$_2$, Cu(NO$_3$)$_2$ and Zn(NO$_3$)$_2$. In changes of color during storage, Hunter's L- and b-value of beef were not changed, but Hunter's a-value was low significantly. The pH of beef meats were low at 6 days, but were added from 6 days. TBA value of beef in "A" pottery containing TiO$_2$ 1% and "C" Pottery containing TiO$_2$ 0.5%, Cu(NO$_3$)$_2$ were lower than "B", "D" and "I" pottery. VBN contents of beef in "A", "B", "C", "D" and "I" Pottery stored during 12 days were 9.8, 12.5, 9.3, 11.9 and 13.7mg%, respectively. In changes of total plate count of beef during storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.g storage at 4$^{\circ}C$, the antimicrobial activity of "A" and "C" pottery were superior.ttery were superior.

• 수산해양교육연구
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• 제27권4호
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• pp.973-980
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• 2015

This study was done to investigate the quality characteristics of salmon frame with citric acid pretreatment. Sliced salmon frame samples were cured in soy sauce, sugar, pepper, and sodium nitrate for 12 h and then dried at 3 h and then dried at $60^{\circ}C$ for 3 h. As the autoclaving at $130^{\circ}C$ for 15 min, the pH, moisture content, crude ash, crude fat, crude protein, acid value (AV), peroxide value (POV), volatile basic nitrogen (VBN), trimethylamine (TMA), total plate count and E. coli were measured at $4^{\circ}C$, $25^{\circ}C$ and $35^{\circ}C$ of storage days. The AV, POV, VBN, TMA and total plate count for all samples significantly increased as during storage days (p<0.05). All samples of storage, for autoclaving on salmon frame, there were no growth on E.coli. In the making of autoclaving on salmon frame, technologies for more safety from microbial growth should accompany pretreatment with citric acid.

• 대한가정학회지
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• 제43권2호
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• pp.19-31
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• 2005

The purpose of this study was to evaluate the microbiological quality and assure the hygienic safety of the Bibimbap production in elementary school foodservice in accordance with the HACCP(Hazzard Analysis Critical Control Point) program. The time-temperature relationship and the microbiological quality(total plate count and coliform bacteria count) were assessed to find the critical control point(CCP) during each of the production phase. In the pre-preparation phase, the risk factors of the raw ingredients exceeded the standard level suggested by Solberg et al. Mungbean starch jelly, egg and Kochujang were satisfactory in that no coliform groups were observed over the standard TPC level. In particular, there was a high the risk of beef from the early stages in terms of the coliform level. In the pre-preparation phase, green pumpkin had more coliform groups than the standard level even after washed, which calls for special attention to washing, sterilization, secondary infection of the handler, and the required time for pre-preparation of raw vegetables. In the cooking phase, the temperature of the soybean sprout and mungbean starch jelly decreased to 42$^{\circ}C$ and 26$^{\circ}C$, respectively, which was within the risk zone. In particular, mungbean starch jelly had a great risk factor even after boiling in hot water. During the storage stage before serving, a lot of ingredients were exposed to poor management of temperature and time and thus exceeded the standard level in the total plate counts. In particular, the microbiological count of beef was five times the standard level. Green pumpkins and soybean sprouts were left at 15-38$^{\circ}C$ that is within the risk zone for a long period of time after they were cooked. It is highly recommended that the time of the storage stage before consumption should be shortened and that proper devices should be used to prevent proliferation of bacteria. The number of TPC of the utensils was satisfactory enough, but the knife used exceeded the standard level and thus was a risk factor of bacteria proliferation.

• 한국식품조리과학회지
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• 제16권2호
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• pp.99-111
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• 2000

The purpose of this study was to assess the qualities of cook/chilled soy sauce-glazed soybean curd with various packaging conditions as a trial to develop health-oriented convenience foods. The effects of three packaging methods, linear low density-polyethylene (LLD-PE), top sealing, and modified atmosphere packaging(MAP) on the shelf-life of HACCP-based cook/chilled soy sauce-glazed soybean curd were evaluated during 20 days of chilled storage in terms of time-temperature, microbiological (total aerobic plate count, psychrotrophic plate count, coliform, and fecal coliform count), chemical(pH and peroxide value(POV)), and sensory evaluation. The results of microbiological and chemical analyses were within the limits of the microbial and chemical standards for all phases after cooking. No significant differences were detected in microbial counts of the samples for all three packaging methods. However, sensory evaluation indicated that the top sealing and MAP methods showed a longer shelf-life than LLD-PE packaging. Recommended shelf-life of the product was 12 days for LLD-PE packaging, and 16 days for both top sealing and MAP. In conclusion, MAP was considered as the most effective packaging method for assuring microbial and sensory quality of this cook/chilled product.

• 한국식품조리과학회지
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• 제20권6호
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• pp.589-597
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• 2004

This study was conducted to investigate the effects of various kinds of electrolyzed and chlorinated waters on the sensory and microbiological qualities of fresh-cut lettuce and to determine the most suitable electrolyzed water for the vegetable dishes, without heat treatment, at institutional foodservices. The sensory evaluation resulted in higher scores on the 1st-day of storage for the EW-1 (diaphragm type 1) and EW-3 (non-diaphragm type) compared to that for EW-2 (diaphragm type 2), with regard to their appearance, discoloration, texture, taste and overall acceptability characteristics. However, over time, EW-3 ranked highest, with a score of 8.00 (very like), on the 4th-day of storage, which maintained the highest level up to the 7th-day of storage, at which time the score was 7.00 (fairly like). The CW (chlorinated Water) had a significantly lower score, due to the smell of chlorine, although there was no concern with relation to chlorine residue from the electrolyzed waters. Microbial examinations of the total plate count revealed that immersing lettuce into EW-3 brought about l/3,000 to 1/30,000 reductions in the microbial counts of the TW treatment or untreated samples for up to seven days of storage. The CW treatment gave a 1/10 reduction in the microbial counts compared with the TW (tap water) treatment. The coliform bacterial counts also showed similar trends to those of the total plate count values. With regards to the psychotropic bacterial count, EW-3 was able to result in as much as a 1/30,000 reduction in the initial counts. As vegetable dishes, such as salad, can not be heat-sterilized, the utilization of EW-3 for the preparation of vegetable dishes without heat treatment will be an excellent choice to improve the critical control point in production state as a new effective means for sanitizing management.

• 한국동물위생학회지
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• 제21권2호
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• pp.157-161
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• 1998

To get the information of sanitary develoment of beef and pork, we get the result of environmental specimens(slaughter house floors, sewage, etc) in laboratory. 1. After examination of bacterial infection on after-bleeding, after-dismemberment and final products at each stage of cattle slaughter process, we got log 3.80~7.48cfu/$\textrm{cm}^2$ of aerobic plate counts and log 2.60~5.23cfu/$\textrm{cm}^2$ of coliform counts or so from the carcasses after bleeding, but these count levels went down little bit after dismemberment but as we continued study to the final products, the count levels kept sililar in mumbers. 2. At the slaughter process of pigs, the aerobic plate counts and the coliform counts reached such high levels of log 5.59~8.80cfu/$\textrm{cm}^2$ and log 3.31~5.67cfu/$\textrm{cm}^2$, respectively, after bleeding, in general, these count diminished in a big way after scalding, but they increased just little bit from dismemberment to final products. And there were few differences in the contamination levels on the final products no matter what seasonal contaminations after bleeding. 3. Test revealed very low levels of cell counts both on the aerobic plate counts of washing water and in the coliform counts, the former was log 1.00~2.69cfu/$\textrm{cm}^2$ and the later was log 3.30~5.67cfu/$\textrm{cm}^2$, but the contamination levels on the beds of transfering vehicles for carcasses were very high as followes : the aerobic counts was log 4.23~7.20cfu/$\textrm{cm}^2$ and coliform counts was log 2.86~5.20cfu/$\textrm{cm}^2$. 4. Study showed the aeroboc plate counts and the coliform counts get to the highest levels in summer, the second highest one is in fall, the third in spring, lowest in winter. Resulting from the test results proven above we reached this kind of conclusion the bacterial contaminations on eatable carcasses were upto hygienic treatment of carcasses and cleaniness of transfering vehicles at the final stop of slaughter processes rather than upto at any stage of slaughter processes. Therefore we have got to establish alternatives immediately to develo sanitary quality of meat and pork.