• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.60-66
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• 2014

This test was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 20% ortho-phenylphenol against Pseudomonas aeruginosa (P. aeruginosa) and Enterococcus hirae (E. hirae). In preliminary tests, P. aeruginosa and E. hirae working culture suspension number (N value) were $2.8{\times}10^8$ and $4.0{\times}10^8CFU/mL$, respectively. And all the colony numbers on the carriers exposed to the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of P. aeruginosa and E. hirae recovered on the control-carriers (T value) was $2.8{\times}10^8$ and $3.4{\times}10^6CFU/mL$, respectively. In the bactericidal effect of the fumigant, the reduction number of $2.8{\times}10^8$ (d value) was 6.46 and 5.19 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results from this study, the fumigation disinfectant containing 20% ortho-phenylphenol has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with the pathogenic bacteria.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.249-257
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• 2015

The purposes of this study were to develop a small scale post-harvest facility, and consequently to evaluate the effects of applying the facility along with hygiene education on the level of microbial safety in Korean leeks production. A total of 135 samples were collected at three Korean leeks farms in Yangju, Gyeonggi province. Food safety indicators (Aerobic plate count (APC), coliform count, and Escherichia coli) and foodborne pathogens (E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus) on/in the samples were assessed. The microbial load measured as APC with harvesting tools such as comb, chopping board, and knife, at the farms where the small scale post-harvest facility had been operated (Farms A and B) was lower than that at another farm having no post-harvest facility (Farm C) by 1.44~2.33 log CFU / $100cm^2$. Moreover, the chopping board from Farm C was observed being contaminated with B. cereus at 6.03 log CFU / $100cm^2$. The coliform counts from the samples increased by 0.57~1.89 log CFU/g after leeks was submerged in ground water for washing. E. coli was recovered from leeks, soil, and the ground water used in the washing process, while no E. coli O157:H7, Salmonella spp., and L. monocytogenes was detected. Our results indicated that the small scale post-harvest facility developed in this study as well as the hygiene education played an important role in enhancing the level of microbial food safety in the leeks production environment. However, a disinfection technique could be needed during the washing step in order to prevent a potential contamination.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.432-441
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• 2012

In this study, the transfer rate of wild type Listeria mon, ytogenes (LM) was investigated to establish the standard of safety management during pork meat pr, essing for meat to meat and meat to food contact surfaces contamination at 5 and $10^{\circ}C$. The transfer rate of LM from meat to meat during the pr, essing increased from 0.02% after 30 min to 0.42% after 120 min at $5^{\circ}C$, while for conveyor belt and stainless steel, it decreased from 0.015% and 0.013% after 30 min to 0.002% and 0.0003% after 120 min at $5^{\circ}C$, respectively (p < 0.05). When temperature increased to $10^{\circ}C$, the transfer rates of LM from meat to meat, conveyor belt and stainless steel were the highest at 60 min exposure, and all decreased after 120 min. In reverse, the transfer rate from food contact surface to pork meat was significantly higher than that from pork meat to food contact surface (p < 0.01). Also, the transfer rate to conveyor belt was significantly higher than stainless steel (p < 0.05) and it was highest at 30 min exposure time in both 5 and $10^{\circ}C$. This study indicates that the transfer and adherence rates of LM are influenced by the contact time and temperature. Consequently, these results were utilized to develop a predictive model with a high level of confidence which can lead to prevent cross-contamination during pork meat processing.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.268-277
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• 2014

This study assessed microbiological hazards at postharvest stage of dropwort farms (A, B, C, D, E, F, G, H, I) located in 4 different areas in Korea. The samples were assessed for sanitary indication bacteria (total aerobic bacteria, coliform, and Escherichia coli) and pathogenic bacteria (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus). Total aerobic bacteria and coliform in 9 dropwort farms were detected at the levels of 0~7.00 and 0~4.25 log CFU/g, mL, of $100cm^2$. In particular, microbial contamination in worker's hand showed higher than cultivation environment factors. Escherichia coli was detected in several farms of soil, irrigation water, washing water and worker's hand and also, dropwort in these farms was contaminated with E. coli (positive reaction). In case of pathogenic bacteria, B. cereus was detected at the highest levels in soil. S. aureus was detected qualitatively from only one sample of dropwort washed by water. E. coli O157:H7 and L. monocytogenes were not detected. Although dropwort pass through 2 process (trimming and washing), the microbial contamination was not differ significantly before and after which indicates that current washing system was not effect on reduction of microorganism. From these results, the postharvest environment and workers have been considered as cross-contamination factors. Thus, processing equipments and personal hygiene should be managed to reduce the microbial contamination of dropwort. Accordingly management system such as good agricultural practices (GAP) criteria is needed for the safety of dropwort

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.485-492
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• 2017

This study investigated to determine the microbial contamination levels of strawberries at harvest and distribution stages and to suggest a control measure for reducing the microbial contamination of strawberries by replacing worker's gloves used at harvest and distribution stages. According to the monitoring results, the contamination levels of total aerobic bacteria (TAB) were in the order of soil ($7.12{\pm}0.61{\log}_{10}CFU/g$), gloves ($6.06{\pm}1.80{\log}_{10}CFU/cm^2$), strawberry ($3.28{\times}0.98{\log}_{10}CFU/g$), and water ($3.08{\pm}0.55{\log}_{10}CFU/g$) at harvest stage. TAB of strawberry at was harvest stage reduced from $3.28{\pm}0.98{\log}_{10}CFU/g$ to $1.85{\pm}0.21{\log}_{10}CFU/g$ and $2.6{\pm}0.30{\log}_{10}CFU/g$ at cold and room temperature storage, respectively. By the replacement of worker's gloves and distribution temperature, TAB levels of the strawberries were significantly reduced when compared to those of the strawberries treated without replacement of worker's gloves and distributed at room temperature. For reusing the replaced gloves, washing with a commercial disinfectant, clorox, was effective to reduce microorganisms contaminated on the worker's gloves. These results demonstrated that appropriate replacement of gloves at the harvest and distribution stages is an effective method for reducing microbial contamination of fresh strawberries.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.195-200
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• 2005

Three different commercial Kimchi industry-made packaged, department store-made and ordinary market-made were analyzed for their pH, acidity and microbiological characteristics including certain harmful bacteria on selective media during a storage-fermentation period of 7 days at $2^{\circ}C\;or\;20^{\circ}C$ The pH of all the Kimchi samples wasdecreased from 5.85 to 3.82 and their total acidities increased from 0.2 to 1.18 as the fermentation continued during the storage-fermentation. E. coli and Salmonella sp. of $0\~1101$ cfu/mL were found in the industry-made Kimchi just after purchase time. As the storage-fermentation proceeded, the viable numbers of these bacteria had been reduced in all Kimchi samples tested and no bacteria were detected after 5 days at $2^{\circ}C$ and 2 days at $20^{\circ}C$, respectively. On the other hand, a range of $7.9102\~2.9103$ cfu/mL of Staphylococcus sp. was detected in the department store-made and ordinary market-made Kimchi samples at the purchase time, which was higher than that of the industry-made Kimchi, and this range wasn't reduced during storage-fermentation. The viable number of yeasts in the market-made Kimchi was 2.1103 cfu/mL. These results suggest that some commercial Kimchis were contaminated by some harmful bacteria and that a portion of these bacteria remained alive in the Kimchi, even with high acidity during the edible period.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.916-923
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• 1998

To provide more information on the enteric pathogen Campylobacter jejuni in the view of food sanitation, survival characteristics of two strains of C. jejuni in the different conditions were investigated. When $10^7{\;}or{\;}10^3{\;}per{\;}ml$ of C. jejuni cells were inoculated in the supplemented Brucella broth and kept at $42^{\circ}C,{\;}25^{\circ}C{\;}and{\;}5^{\circ}C$ under the static aerobic condition for 7 days, organisms exponentially proliferated to $a{\;}>10^8$, even in the $10^3{\;}per{\;}ml$ inoculated-sample at $42^{\circ}C{\;}for{\;}1{\sim}2{\;}days$ and the considerable level of viability maintained during 7 days. At $5^{\circ}C$, most of the initial level of organisms survived at the early period and only $a{\;}<{\;}0.5-log_{10}$ cells decrease were observed during the 7 days. At $25^{\circ}C$, a remarkable number of C. jejuni declined within $1{\sim}2{\;}days$ and showed undetectable level of cells after 4 days. When sterile milk and minced chicken meat were artifically inoculated with $10^7{\;}per{\;}ml$ of C. jejuni, mostly, a $1-to{\;}2-log_{10}$ count decrease occurred at $42^{\circ}C{\;}and{\;}5^{\circ}C$ while $a{\;}>3{\;}log_{10}$ decrease at $25^{\circ}C$ during 7 days. Unexpectedly, no colonies appeared on the plate inoculated from the minced chicken meat sample kept at $42^{\circ}C$ after 4 days. The results suggest that C. jejuni contaminated to food can survive at the refrigeration temperature whereas they are sensitive to at the room temperature. Also, it is shown that the growth of C. jejuni at the optimal temperature may vary to the food sources.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.525-528
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• 2001

This study was conducted to estimate the contents of heavy metals in some health foods available on Korean markets. The samples were digested with microwave system, then analyzed using GF-AAS for the contents of lead (Pb), cadmium (Cd) and arsenic (As). The contents of mercury (Hg) were determined using a mercury analyzer. The average values of Hg, Pb, Cd and As in calcium (Ca) health foods were 0.007, 1.08, 0.02 and 0.48 mg/kg respectively. Those values in chitosan health foods were 0.001, 0.36, 0.01 and 0.03 mg/kg respectively. Those values in propolis health foods were 0.013, 4.96, 0.01 and 0.13 mg/kg, respectively. The health foods that contained cow bone powders had the highest lead contents. Based on the variation in lead contents of those products, it could be possible that they might be contaminated through raw materials and/or manufacuring process. Some propolis products were also very high in lead contents. There could be risks for some population, especially the aged who overtake those health foods, to have heavy intake of lead. Therefore, we established the lead standards of 3.0, 2.0 and 5.0mg/kg less than for Ca, chitosan and propolis health foods respectively, based on the Codex method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.71-76
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• 1998

To know the antibiotic specificity of a Dinoflagellate, Cochlodinium polykrikoides, we investigated the survival time of C. polykrikoides against several concentrations of antibiotics and judged the selective specificity of antibiotics based on the $LT_50$ ($50\%$ of lethal time). The result showed that C. polykrikoides was sensitive to tetracycline and chloramphenicol, and resistant to polymixin-B, ampicillin, penicillin-G, dihydrostreptomycin, and neomycin. In the case of sensitive antibiotics to C. polykrikoides, tetracycline and chloramphenicol, the safety concentrations of both antibiotics were determined and the antibiotic specificity based or the plotted survival curve was analyzed. Before antibiotic treatment, we tested the antibiotic susceptibility of the contaminated bacterial population in tile culture of C. polykrikoides, and decided the proper kinds of antibiotics and concentrations before percoll-centrifugation. By percoll-centrifugation, we reduced bacteria, removed fungi, collected the algal pellet, and made axonic culture by antibiotic cascade procedure based on the result of antibiotic susceptibility test. We observed that axonic C. polykrikoides culture entered the logarthmic phase of growth when cell density was over 740 cells/ml and propagated to 5,800 cells/ml maximally. Divisions per day, k value of C. polykrikoides represented a good index for growth at the low density of cells. There was a highest k value shift before reaching to the logarithmic phase. We suggested that the preceeding highest k value shift stage is a good indicator for accurate broadcasting for red. tide blooming in the field, and the stage is also a good time for controlling red tide blooming in the filed, either.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.796-801
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• 2001

A total of 277 mineral spring water samples in Kangwon province from 1999 to 2000 were analyzed for the presence of Yersinia spp. by the conventional Food and Drug Administration protocol, and presumptive strains were identified by morphological, cultural and biochemical tests according to Bergey’s manual. Also, the biotypes, serotypes, and susceptibility to 12 antibiotics were tested. Among the total 277 mineral spring water samples, 40 samples (14.4%) were found to be contaminated with Yersinia species. Among the 40 strains of Yersinia spp. isolates, 33 strains (82.5%) for Yersinia enterocolitica, 4 strains (10%) for Yersinia frederiksenii, 2 strains (5%) for Yersinia intermedia, and 1 strain (2.5%) for Yersinia sakazaki were identified, respectively. Of 40 Yersinia spp. isolates, Yersinia enterocolitica (82.5%) was the most predominant species in the mineral spring water samples compared to other Yersinia species. Compared to direct culture method after KOH treatment and KOH treatment method after cold enrichment for better isolation ratio of according to comparision of Yersinia species, the detection ration (18.5%) of KOH treatment method after cold enrichment was about 3 times better than that (6.1%) of direct culture method after KOH treatment. According to serotypes of Y. enterocolitica isolates, O : 5 (12.9%) was the most predominant and followed by O : 3 (9.7%), O : 8 (6.5%), and O : 9 (3.2%), and others. For biotypes of Y. enterocolitica isolates, 1A (71.0%) was the most predominantly abundant and followed by 3A (12.9%), 3B (9.7%), 1B (3.2%) and 5 (3.2%). Also, an antibiotic susceptibility test showed that Yersinia spp. isolates were very susceptible to the antibiotics tested, but they were very strongly resistant to ampicillin, cephalothin and carbenicillin.