• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.30-36
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• 2012

This study was conducted to evaluate the microbiological hazard on nursery school children's hands and to investigate the reduction effect of hand washing education. A total of 59 nursery school children's hands were tested. The average number of total aerobic bacteria was $3.72{\pm}0.38log\;CFU/hand$. Five children's hands(2 male and 3 female) were positive(14.3%) for the coliform bacteria. These results showed that hand washing education are required repetitively. Among the pathogenic bacteria tested in this study, $Staphylococcus$ aureus and $Bacillus$ $cereus$ were detected in 9(25.7%) and 16(45.7%) out of 35 their hands, respectively. Twelve out of sixteen $B.$ $cereus$ isolates(70.0%) produced enterotoxin. The results indicate that the hand hygiene of nursery school children needs to be improved. Comparing before and after hand washing in educated and non-educated group, the reduction effect of total aerobic bacteria on their hands was 0.42 and 0.60 log CFU/hand, respectively. The educated group showed 0.18 log CFU/hand higher reduction effect than non-educated group but microorganism did not eliminate perfectly. From the results, using a hand sanitizer after washing with soap and the continuous hand washing education are required to control the contaminated bacteria on nursery school children's hands.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.477-488
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• 2020

Recently, foodborne illness outbreaks linked to fresh produce are being increasingly reported in the United States, the EU, and Korea as well. Some of this increase may be due to improved surveillance, increase in consumption, change in consumers' habits, and complex distribution systems. Garlic chive is a green, fresh-cut vegetable consumed year-round as a nutrition-rich herb in Korea. It is also prone to contamination with foodborne pathogens during pre-harvest, as amendment with high amounts of livestock manure or compost to soil is required in its cultivation. Our aim in this study was to evaluate microbial contamination of garlic chives, garlic chives cultivation soil, compost, and irrigation water in the southern part of Korea. Samples were collected in A, B, and C regions in 2019 and 2020, and 69, 72, 27, and 40 of garlic chives, soil, compost, and irrigated water, respectively, were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Bacillus cereus, Staphylococcus aureus, pathogenic E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In A, B, and C regions, levels of total aerobic bacteria, coliform, B. cereus, and S. aureus on all samples were between 1.14 and 8.83 log CFU/g, 0.43 and 5.01 log CFU/g, 0.41 and 5.55 log CFU/g, and 1.81 and 6.27 log CFU/g, respectively. B. cereus isolated from garlic chives and environmental samples showed β-hemolysis activity. Incidence of S. aureus in garlic chive and its production environments in 2020 was different from 2019. In this study, B. cereus and S. aureus were the only pathogenic microorganisms detected in all samples. As a result, this work suggests that continuous monitoring in the production and pre-harvest environment is required to improve hthe hygiene and safety of garlic chive.

• Journal of Dairy Science and Biotechnology
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• v.36 no.2
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• pp.106-120
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• 2018

Since 2018, the production and sales of ram-milk cheese ripened for over 60 days has been permitted in South Korea. Hence, this study aimed to examine the microbiological changes in 7 different types of Gouda cheese. During the aging period, traditional raw-milk Gouda Cheeses 1 and 2 did not contain Salmonella spp. during the 60-day storage period and no E. coli after 20-day storage. Coliform bacteria were not detected in Cheese 1 after 40 days; however, they were detected in Cheese 2 up to 60 days. Salmonella spp. were inhibited during the 60-day storage period in Cheese 3 (Salmonella spp.-contaminated raw-milk Gouda cheese), Cheese 4 (Cheese 3 contaminated with lactic acid bacteria DH 5 isolated from Kefir) and Cheese 5 (Cheese 3 contaminated with lactic acid bacteria DN1 isolated from Kefir). In particular, inhibition of Salmonella spp. was more prominent in Cheese 4 and Cheese 5 than in Cheese 3. During 60-day storage, Cheese 6 had a significantly reduced lactic acid bacteria. Furthermore, in Cheese 7, E. coli, E. Salmonella ssp. were rarely detected, and lactic acid bacteria were slightly greater in Cheese 7 than in other cheeses during the 60-day period. Moreover, all samples from Cheese 1 to Cheese 7 were not contaminated with Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, and E. coli O157:H7.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.249-254
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• 1997

The constructed wetland system which is applicable to rural wastewater treatment was examined by pilot plant experiment. Removal rates of nutrients including nitrogen and phosphorus and total coliform were evaluated. The $NH_4\;^+$ concentration of the influent was in the range of 91.57 to 275.88mg/l and the effluent concentration was about 40% lower than the influent. The decreasing of the $NH_4\;^+$ concentration might be due to volatilization, plant uptake, adsorption onto soil particles, and mainly nitrification. However, generally concentrations of $NO_2\;^-$ and $NO_3\;^-$ were increased in the effluents compared to the influent concentrations, which implies that nitrogen components in the system were nitrified. Overall, the average removal rate of the nitrogen was about 5% which seems inadequate as a wastewater treatment system, and this system needs improvement on nitrogen removal mechamism. The removal rate of the phosphorus was quite high and effluent concentration was very low. Reason for high removal rate of the phosphorus might be mainly strong adsorption characteristic onto soil particles. The average removal rate of the total coliforms was about 83%, and main removal mechanisms are thought to be adsorption onto soil and inability to compete against the established soil microflora. From the results of the study, the constructed wetland system needs to be improved in nitrogen removal mechanism for field application.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.413-418
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• 2011

This survey was conducted to monitor the safety of red ginseng products in Gwangju, in 2010. Among 100 samples, 37 were beverages, 5 were functional health foods on the market, and 58 were beverages from a tailor-made shop. All samples were negative for coliform bacteria. Aerobic plate counts were detected from 13 samples in the 58 tailor-made products but not detected in the other types of products. Benzoic acid was detected in 5 samples (range, 19.2-543.0 mg/kg). Among heavy metals, lead was detected, ranging from 28.8-62.3 ${\mu}g/kg$, cadmium, from 1.15-4.18 ${\mu}g/kg$, and mercury from 0.10-0.18 ${\mu}g/kg$. Benzopyrene was not detected in any samples. Ginsenoside Rg1 and Rb1 were detected in 0.1-23.4 mg/90 mL of beverages and 12.1-66.8 mg/90 mL of functional health foods. These results indicate that red ginseng products are safe in terms of microbial contaminants and hazardous chemical compounds such as heavy metals and benzopyrene.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.495-503
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• 2011

We evaluated the quality characteristics of fresh-cut produce (potato, sweet potato, carrot, radish, zucchini, cucumber, and green bell pepper) washed with sodium hypochlorite, which were vacuum packaged, and stored at 4 and 10$^{\circ}C$. The L-values of the fresh-cut potato and sweet potato decreased during storage. Lower PPO activities of potato and sweet potato were observed at 4$^{\circ}C$ than those at 10$^{\circ}C$ and development of potato and sweet potato browning was delayed at 4$^{\circ}C$. Total aerobic count and coliform increased continuously at 10$^{\circ}C$ during storage. Diced zucchini and shredded sweet potato had the greatest reduction in hardness among the fresh-cut produce during storage. Differences in the rate of quality change were observed according to the kinds and cut types of produce. Thus, a quality maintenance period for each type of fresh-cut produce must be determined, which will lead to the safe use of fresh cut produce in foodservice establishments.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.295-300
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• 2012

The purpose of this study was to analyze microbiological hazards for plants, cultivation environments and personal hygiene of perilla leaf farms at the harvesting stage. Samples were collected from three perilla leaf farms(A, B, C) located in Gyeongnam, Korea and tested for sanitary indications, fungi and pathogenic bacteria(Escherichia coli O157:H7, Listeria monocytogens, Salmonella spp., Staphylococcus aureus and Bacillus cereus). As a result, total bacteria and coliform in perilla leaf were detected at the levels of 4.4~5.2 and 3.4~4.3 log CFU/g, respectively, but E. coli was not detected in all samples. Among the pathogenic bacteria, B. cereus(perilla leaf: 2.0~2.4 log CFU/g, stem: 1.4~2.1 log CFU/g, water: 0.7 log CFU/ml, soil: 4.2~5.0 log CFU/g, hands: 3.0 log CFU/ hand, gloves: 2.1~2.4 log CFU/100 $cm^2$, glothes: 1.5~2.8 log CFU/100 $cm^2$) and S. aureus(3.4 log CFU/hand) were detected in all samples and worker's hand from farm A, respectively. However, other pathogenic bacteria were not detected. This study demonstrates that perilla leaf at the harvesting stage was significantly contaminated with microbial hazards.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.324-329
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• 2013

This study investigated and evaluated contamination levels of bacteria on tomatoes at farms stage to evaluate potential hazards associated with fresh tomatoes. A total of 170 samples, 90 samples from 5 sampling sites from 18 farms and 80 samples from 1 sampling site from 4 farms every month for four months, were analyzed to enumerate aerobic bacterial counts, coliforms, E. coli, Bacillus cereus, Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes. Aerobic bacterial counts ranged from 0.48 to 6.15 Log CFU/g, with the lowest and the highest bacterial cell counts recorded for A site and E site, respectively. Thirty five percent of the samples from the E site contained more than 2 Log CFU/g. Six samples (6.6%) of 90 samples contained B. cereus less than 1 Log CFU/g. In addition, the contamination level of indicator bacteria and B. cereus in tomatoes were higher on March than on April, May and June (P < 0.05). S. aureus, E. coli, E. coli O157:H7, Salmonella spp. and L. monocytogenes were not detected in the tomato samples. The microbial contamination levels of tomatoes determined in this study may be used as the data for microbiological risk assessment.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.404-411
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• 2018

To evaluate bacteriological and toxicological safety hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in Hansan Geojeman 2013-2017 were investigated. Fecal coliforms were < 18~330 MPN/100 g in 404 oyster samples. But all samples tested, did not exceed 230 E. coli MPN/100 g. Geometric mean of E. coli for oyster samples collected during major shellfish production period was 24.3 MPN/100 g, considerde stable results. Bacteriological quality of oysters collected from Hansan Geojeman meets the standard value based on shellfish hygiene of the Food Sanitation Act of Korea and also meets Grade A, according to classification of shellfish harvesting areas of the European Union. For toxicological evaluation of Hansan Geojeman, 532 oyster samples and 268 mussel samples as an indicator, were analyzed. Paralytic shellfish toxins were detected in the range of 0.42~2.29 mg/kg in eight mussel samples, and exceeded criteria in three samples from early to late April 2013. Diarrhetic shellfish toxin was detected in three of 120 samples, but it was revealed to be under regulation value (0.16 mg Okadaic Acid equ./kg). As a result of toxicological evaluation, paralytic and diarrhetic shellfish toxins were not detected in oyster samples, but it was found that mussel as an indicator species, exceeded the threshold value of paralytic shellfish toxin. Accordingly, sanitary surveys were continuously requested for food safety management of shellfish.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.75-82
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• 2020

The purpose of this study was to establish optimized extraction conditions for Lilium bulb and Lespedeza cuneata G. Don and to investigate the storage stability of beverages containing extracts. The hot-water extract and the 60% ethanol extract had the highest DPPH radical scavenging activities as well as the highest total polyphenol content. The total polyphenol content, total flavonoid content and DPPH radical scavenging activity were the highest when the Lilium bulb extract was mixed with the Lespedeza cuneata G. Don extract at the ratio of 1:4. Storage stability of beverages was determined during storage at 10, 25, and 35℃ for 6 months. The pH was decreased from 4.15 to 4.01-4.05, while the acidity was increased from 0.60% to 0.70-0.75% after storage for 6 months. The soluble solid contents were not changed during storage of 6 months. The DPPH radical scavenging activity was decreased after 4-6 months. The Hunter b (yellowness) values decreased at 35℃ after storage for 6 months while the lightness (L) and redness (a) were not changed during storage for 6 months. The total saponin content was not remarkably changed during 2 months of storage, while it decreased after 4-6 months of storage. The flavonoid content was decreased 47% and 55% from an intial 21.7 mg/100 mL to 10.3 mg/100 mL and 12.0 mg/100 mL after 1 month of storage and then remained stable until 6 months. General bacteria and coliform group were not detected during storage for 6 months.