• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.937-940
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• 2011

물/유기용매의 혼합용액에 키토산을 분산시키고 이 현탁액에 글리시딜 트리알킬 암모늄염, 글리시딜 아릴염 등의 에테르 시약을 상온에서 현탁상태로 반응시켜 4급화 키토산을 제조하는 새로은 방법을 개발하였다. 이 방법으로 합성한 결과 수득율이 90%이상이었으며 후처리과정이 필요없었다. 4급화 키토산의 균에 대한 최소저지농도(MIC)를 조사한 결과 E. coli O157:H7 균주의 MIC는 0.007%-0.01%(70-100ppm)로 추정되었고 V. vulnificus 균주의 MIC는 0.005%(50ppm)정도이고 V.vulnificus 균주의 MIC는 0.007%(70ppm)이었다. 작물에 대한 항균성을 알아보기 위하여 4N-키토산의 항균 활성만이 검정되었는데, 4N-키토산은 고추 역병균인 P. capsici에 대하여 가장 높은 항균 활성을 보여 4,000 ppm에서부터 키토산 무첨가 대조구에 비하여 항균활성을 보였으며 P. capsici보다는 약하지만 잿빛곰팡이병균 B. cinerea에 대하여도 약간의 항균 활성을 보이고 있어, 16,000 ppm에서는 항균서이 뚜렷이 나타났으나 고추 탄저병균인 C. gloeosporioides에 대해서는 16,000 ppm 이라는 높은 농도에서도 항균 활성을 전혀 보이고 있지 않았다.

• Food Science of Animal Resources
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• v.40 no.2
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• pp.221-230
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• 2020

The aim of this study was to evaluate the antioxidant and antibacterial activity of Hovenia (Hovenia dulcis) monofloral honey produced in Korea. To produce Hovenia monofloral honey, Hovenia trees were surrounded by a net house, and honeybees were breed there over a 20-day period. Hovenia monofloral honey contained more than 95% of Hovenia pollen and showed physicochemical properties in agreement with the international honey standard (Codex). The total phenolic and flavonoid contents of Hovenia monofloral honey ranged from a 24.82-27.00 mg gallic acid equivalent/100 g honey and a 0.41-0.46 mg quercetin equivalent/100 g honey, respectively. In addition, to evaluate the functional properties of Hovenia monofloral honey, the antioxidant activity of Hovenia monofloral honey was estimated by using the 1,1-diphenyl-2-picrylhydrazyl radical and the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay. Furthermore, Hovenia monofloral honey showed an antibacterial activity against foodborne gram positive (Listeria monocytogenes and Staphylococcus aureus) and gram negative bacteria (Salmonella Typhimurium and Escherichia coli O157:H7).

• Food Science of Animal Resources
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• v.35 no.5
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• pp.611-614
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• 2015

This study was performed to apply a protein film containing a natural antimicrobial compound to meat packaging and determine quality change of meat during storage. Proteins obtained from the by-products of food processing have been utilized as biodegradable film sources. Porcine meat and bone meal (MBM) is obtained during meat processing, and proteins from the MBM can be extracted and used as a film base material. Previously, an antimicrobial MBM film containing coriander oil (CO) was prepared and its physical properties and antimicrobial activity were characterized. In this study, the antimicrobial MBM-CO film was applied to beef patties packaging, and the microbial population and the degree of lipid oxidation were determined during storage at 4℃ for 15 d. The population of inoculated E. coli O157:H7 in the samples wrapped with the MBM-CO film was 6.78 log colony forming unit (CFU)/g after 15 d of storage, whereas the control had 8.05 Log CFU/g, thus reducing the microbial population by 1.29 Log CFU/g. In addition, retardation of lipid oxidation in the patties was observed during storage for the samples packaged by the MBM-CO film, compared with the control samples. These results suggest that the MBM-CO film can be useful for enhancing the quality of beef patties during storage.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.125-129
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• 2007

Artemisia capillaris THUNB is a perennial herb that belongs to the family Compositae spp and the most common plant among the various herbal folk remedies used in treatment of abdominal pain, hepatitis, chronic liver disease, jaundice and coughing in Korea. This experiment was conducted to investigate the inhibitory effects of orally administrated Artemisia capillaris extracts on the pathogenic bacteria in 200 ICR mice. The experimental groups showed inhibitory effects on the bacteria in $1{\sim}3$ days after inoculation. After 21 days of inoculation, no viable bacterial cells appeared in the feces of both experimental groups while they did appear in the control group. The results of these studies indicate Artemisia capillaris extract exhibited excellent antimicrobial and inhibitory effects on the food poisoning pathogenic bacteria; S. enteritidis, E. coli O157:H7, L. monocytogenes and S. aureus.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.35-43
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• 2013

The substances of lactic acid bacteria (LAB) isolated feom Kimchi and Tarak, L. mesenteriodes LAB kw5, and S. thermophilus LAB KW15 were investigated for growth effect of Helicobacter pylori with IgY and Auricularia auricula. Inhibition of H. pylori was confirmed at LAB KW5 and KW15 supernatants. Interestingly, anti-H. pylori substance in LAB KW5 and KW15 supernatants were sensitive to lipase, but insensitive to protein hydrolase and carbohydrate hydrolase. The inhibition zone toward H. pylori was not shown with the lipase-treated supernatants. Therefore, there seemed to be lipid-like substances in the cultures. By the analyses with gas chromatography, undecanoic acid ($C_{11:0}$), palmitic acid ($C_{16:0}$), stearic acid ($C_{18:0}$), and oleic acid ($C_{18:1}$) were detected at the culture substances from L. mesenteroides LAB KW5 and S. thermophilus LAB KW15, and more eicosadienoic acid ($C_{20:2}$) from L. mesenteroides LAB KW5. Anti-H. pylori substances of LAB with IgY and A. auricula extract were analyzed for inhibition effect of H. pylori. The inhibition increased more by the range from 57% to 86% by the mixture. The substances with IgY and A. auricula extract showed more effective inhibition of H. pylori than single or double trials.

• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.161-168
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• 2011

The purpose of this study was to evaluate microbiological contamination of fresh vegetables in Korea. Twenty types of vegetables were tested for total aerobic bacteria, coliforms, Escherichia coli, yeast and mold, and pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Salmonella, E. coli O157:H7, Cronobacter sakazakii, Shigella, and Campylobacter. Levels of total aerobic bacteria and coliform on 20 vegetables were between 3.74 and 8.04 log CFU/g, and 0.16 and 5.02 log CFU/g, respectively. The highest contamination levels of total aerobic bacteria were observed on water dropwort, sprouts, mungbean sprout, and ballflower root. There was no significant difference (p>0.05) in microbial contamination levels of total aerobic count, coliform, E. coli, yeast and mold between organic and nonorganic vegetables. When isolation methods using selective agars were applied, L. monocytogenes, B. cereus, Salmonella and Campylobacter were isolated from some fresh vegetable samples. Results of API kit tests showed that L. monocytogenes was identified on Chinese cabbage, cucumber, soybean sprouts, and iceberg lettuce while Salmonella was identified on Korean leek. Furthermore, Campylobacter jejuni was also identified in more than 50 of the 100 samples. However, when positive samples from API kit were tested for real-time PCR or 16S rRNA sequencing method, only B. cereus from perilla leaf, carrot, water dropwort, and sprouts showed positive results. These results indicate that selective agar and API kit detection methods might result in false positive results for some pathogens. Therefore, studies need to improve isolation or confirmation methods for such pathogens.

• Food Science and Preservation
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• v.18 no.1
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• pp.7-12
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• 2011

Paprika is a major export of Korea, but biosafety is important if exports are to grow. To date, few paprika biosafety data are available. We evaluated microbiological contamination of paprika, and determined bacterial levels with respect to storage temperature. Mean counts of total aerobic bacteria were $2.3{\pm}0.3\;log_{10}\;CFU/g$, but coliforms were not isolated. Staphylococcus aureus, Salmonella spp., Listeria spp., and Escherichia coli O157 were also not detected. When bacterial contamination of paprika stored at room temperature or $4^{\circ}C$ for 20 days was evaluated, the numbers of total aerobic bacteria peaked at 14-16 days at room temperature (4 times more than those of $4^{\circ}C$). However, aerobic bacteria grew slowly at $4^{\circ}C$. Coliforms were also detected twice at room temperature, but not upon storage at $4^{\circ}C$. The results indicate that the paprika exported from Korea is relatively biosafe. However, food hygiene issues must be addressed to reduce contamination during storage and distribution.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.341-345
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• 2010

Three-hundred samples of powdered infant formula milk and related products from four different manufacturers in 2010 were collected and surveyed their contaminations for aerobic bacteria, coliform, Enterobacter(Cronobacter) sakazakii, and food-borne pathogens. Fifteen samples of sterilized infant formula milk were all negative on these microorganisms. In all collected products of un sterilized infant formulas and follow-on infant formulas, aerobic bacteria were detected at 239 (83.9%) among 285 samples, and they all were found below $10^3$ cfu/g. Coliform bacteria were also detected at four among 285 samples. Salmonella spp. and Ent. sakazakii, weren't detected at the all samples. Bacillus cereus was detected at 24 (8.4%) among 285 samples. The level of B. cereus was below 100 cfu/g but it was suitable for the range of specification of B. cereus in infant formulas. Clostridium perjringens, Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes weren't also detected. In consequence, it was suitable for total viable count, coliform and potential pathogen to the specification of infant formulas and related products.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.313-319
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• 2012

Consumer's preference and microbial inspections on fresh raw beef were carried out to understand the actual market status in Gwanju, Korea. Over 15 questions on questionnaire by 1,111 randomly selected respondents between April and May in 2011, results showed 65.5% positive on eating fresh raw beef, 63.8% negative on good hygiene condition of fresh raw beef, and 72.5% positive on the secure of the hygiene-safety for priority program, respectively. For microbial inspections, a total of 302 samples were collected from fresh raw beef purchased from slaughterhouse (n=122), transport (n=69) and consumer (n=81) stage, from lettuce (n=30) at consumer stage. The aerobic plate count (APC), E. coli count and food borne bacteria such as Salmonella spp., Listeria monocytogenes, Staphylococcus(S.) aureus and E. coli O157:H7 were tested in the samples. As results, the level of count on APC of fresh raw beef ranged $6{\times}10^1{\sim}1.8{\times}10^5CFU/g$ from slaughterhouse, $2{\times}10^2{\sim}8.3{\times}10^5CFU/g$ from transport stage and $1{\times}10^2{\sim}4{\times}10^5CFU/g$ from consumer stage. The level of count on E. coli of fresh raw beef ranged $1{\sim}9{\times}10^1CFU/g$ from slaughterhouse, $1{\sim}7{\times}10CFU/g$ from transport stage and $1{\sim}5.5{\times}10CFU/g$ from consumer stage. In total, 26 S. aureus were isolated, 10 (14.5%) from fresh raw beef at transport stage, 12 (14.8%) from fresh raw beef and 4 (13.3%) from lettuce at consumer stage. Enterotoxin of S. aureus was not detected among 26 isolates. All S. aureus isolates were typed using a DiversiLab$^{TM}$ rep-PCR system for genetic similarity test, showing over 95% of genetic relationship amon isolates.

• Journal of Microbiology
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• v.42 no.3
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• pp.216-222
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• 2004

In a previous paper, the ogdH gene that encodes 2-oxoglutarat dehydrogenase was isolated from Salmonella typhimurium. The catalytic N-terminal region in the enzyme was found to be very specific for the Salmonella species. Therefore, the aim of the present study was to detect S. typhimurium in food sources using primers designed for OGDH-l and OGDH-2 which were based on the salmonella-specific region of the ogdH gene. A simple polymerase chain reaction (PCR) detection method was developed to detect low numbers of S. typhimurium in a chicken meat microbial consortium. Using the ogdH-specific primers under stringent amplification conditions and for gene probe analysis, fewer than 100 colony-forming units (CFUs) were detectable when pure cultures were employed. When the PCR assay was run on S. typhimurium-contaminated meat contents, only the positive meat samples containing as few as 200 CFUs reacted to the assay. The method employed for sample processing is simple and it was determined to provide a sensitive means of detecting trace amounts of S. typhimurium-specific sequences in the presence of mixed meat microbial populations. When compared with six representative intestinal gram-negative bacterial strains in foods, including Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, E. coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., S. typhimurium had a unique and distinct PCR product (796 bp). In conclusion, the two OGDH primers were found to be rapid and sensitive detectors of Salmonella spp for the PCR method.