• 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 and Biotechnology
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• v.18 no.1
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• pp.12-17
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• 2009

The effect of kimchi, traditional Korean fermented vegetables, on inactivating food-borne pathogens and the kimchi factors affecting the antimicrobial activity were investigated. More cells of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium were inactivated in the kimchi that had low pH and high titratable acidity. Of the raw ingredients in kimchi, raw garlic showed the strongest antimicrobial activity against the pathogens. When kimchi was fermented at 0, 4, 10, or $20^{\circ}C$ to pH 4.4, higher kimchi fermentation temperature resulted in higher titratable acidity. The greatest inactivation of S. typhimurium occurred in kimchi fermented at $20^{\circ}C$, while L. monocytogenes were inactivated in kimchi fermented at $0^{\circ}C$ in situ. This study showed that appropriately fermented kimchi can inactivate various food-borne pathogens and that the fermentation temperature of the kimchi is an important factor in determining the ability of the kimchi to inactivate specific pathogens. Lactic acid bacteria (LAB) multiplication and organic acids produced according to LAB metabolism play a role in inactivating food-borne pathogens in kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1353-1360
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• 2011

This study was performed to investigate the antimicrobial effects against food-borne pathogens and antioxidant activity of Rhododendron brachycarpum ethanol-extract. The antimicrobial activity of the extract was determined using a paper disc-diffusion method, and the diameter of the clear zone was measured. The diameter of the clear zone in the presence of 10 mg of extract was maximal against Bacillus cereus among the three tested Gram-positive bacteria and against Escherichia coli O157:H7 among the five tested Gram-negative bacteria. Analysis of the minimum inhibitory concentration (MIC) showed that the extract exhibited a similar efficacy as that of sorbic acid, a well-known chemical preservative. The growth inhibitory effects of the extract at concentrations of 250, 500, 1,000, and 2,000 mg/L on food-borne pathogens were determined against Staphylococcus aureus, Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7. Growth of the microorganisms was not affected by the extract at concentrations up to 250 mg/L, but it was significantly (p<0.05) inhibited by the extract at concentrations higher than 1,000 mg/L. The antioxidant effects of the extract were examined via measurement of DPPH radical scavenging activity, inhibition of reactive oxygen species (ROS) generation using fluorescent dichlorofluorescien (DCF) assay, and prevention of peroxyl radical- and hydroxyl radical-induced supercoiled DNA breakage. The $IC_{50}$ of the extract for DPPH radical scavenging activity was about half that of ${\alpha}$-tocopherol, which was used as a positive control. DCF fluorescence intensity decreased as the concentration of the extract increased, demonstrating that ROS generation was inhibited in a concentration-dependent manner. The ROS inhibitory effect of the extract was higher than that of ascorbic acid. The extract prevented supercoiled DNA strand breakage induced by peroxyl radical and hydroxyl radical. Thus, the results of the present study demonstrate that the extract exhibits antimicrobial effects against food-borne pathogens as well as potent antioxidant capacity, suggesting that R. brachycarpum could be used as a natural antibacterial agent and effective antioxidant in food.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.578-586
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• 2009

This study was conducted to determine the effects of alkaline electrolyzed water (AIEW), acidic electrolyzed water (AcEW), 1% citric acid, and 100 ppm sodium hypochlorite, either alone or in combination with citric acid, in reducing the populations of spoilage bacteria and foodborne pathogens (Listeria monocytogenes and Escherichia coli O157:H7) on lettuce at various exposure times (3, 5, and 10 min) with different dipping temperatures (1, 20, 40, and $50^{\circ}C$). In addition, the inhibitory effect of alkaline electrolyzed water combined with citric acid on the browning reaction during storage at $4^{\circ}C$ for 15 days was investigated. Compared to the untreated control, electrolyzed water more effectively reduced the number of total bacteria, mold, and yeast than 100 ppm sodium hypochlorite under the same treatment conditions. All treatments exposed for 5 min significantly reduced the numbers of total bacteria, yeast, and mold on head lettuce. The inactivation effect of each treatment on head lettuce was enhanced as the dipping temperature increased from 1 to $50^{\circ}C$, but there was no significantly difference at temperatures greater than $40^{\circ}C$ (p<0.05). The total counts of yeast and mold in head lettuce were completely eliminated when a combination of 1% citric acid and AlEW treatment was used at temperatures greater than $40^{\circ}C$. However, decreased reduction in L. monocytogenes (2.81 log CFU/g), and E. coli O157:H7 (2.93 log CFU/g) on head lettuce was observed under these treatment conditions. In addition, enhanced anti-browning effect was observed when the samples were subjected to both 1% citric acid and AlEW treatment at temperatures greater than $40^{\circ}C$ compared to when single treatments alone were used. Thus, this combined treatment might be considered a potentially beneficial sanitizing method for improving the quality and safety of head lettuce.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.110-116
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• 2019

To investigate the antagonistic inhibitory effects in a mixed culture between probiotics and various pathogenic microorganisms, 140 probiotics were identified using a 16 rRNA sequencing phylogenetic analysis method, and various probiotics strains were isolated from Korean kimchi from January to December 2016. The antagonistic inhibition test of a mixed culture of four probiotics (Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus reuteri) with excellent antimicrobial activity and six pathogenic microorganisms (Candida albicans, Salmonella Enteritidis, E. coli O157:H7, Shigella flexneri, Staphylococcus aureus, and Pseudomonas aeruginosa)showed that the growth of most probiotics strains increased normally after culture, but growth was inhibited almost completely in most pathogenic microorganisms, except for S. Enteritidis. This antagonistic inhibitory effect in vitro was attributed to the low pH of the lactic acid and organic acid produced during fermentation. As a result, four probiotics strains isolated from Korean Kimchi are very likely to be developed as therapeutic agents for female yeast infections and colon and skin care. In the future, these therapeutic agents will help improve public health related to probiotics.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.294-300
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• 2019

To investigate the inhibition effect on pathogenic microbes and the antimicrobial resistance of probiotics, a total of 140 probiotics were isolated from 35 kinds of Korean commercially available Kimchi. Of those, L. plantarum was identified from 53 strains (37.9%), E. faecium from 27 strains (19.3%), and L. rhamnosus from 7 strains (5.0%) using 16S rRNA gene sequencing. Sixty nine strains (49.3%) showed overall antimicrobial activity against pathogenic microbes, namely S. Typhi, S. Enteritidis, E. coli O157:H7, S. flexneri, NAG Vibrio, Listeria monocytogenesis, Y. enterocolitica, S. aureus, S. pyogenes, G. vaginalis, C. albicans, and P. acne. The proportions of L. plantarum, E. faecium, and L. rhamnosus strains to pathogenic microbes were 75.5%, 40.7%, and 28.6%, respectively. In addition, a resistance test with 18 antimicrobial agents using a disk diffusion assay revealed a resistance incidence of 98.6% for nalidixic acid, 83.6% for streptomycin, 75.7% for gentamicin 73.6% for vancomycin, 72.1% for norfloxacin, and 67.9% for ciprofloxacin. In conclusion, L. plantarum, L. sakei, and E. faecium strains with various antimicrobial activities and broad antibiotic resistance are useful for treating diarrhea in long-term inpatients and for the alternative use for treating Candida species female vaginitis.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.31-36
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• 2023

This study was conducted to evaluate the efficacy of sodium hypochlorite in eliminating Escherichia coli strains from leafy green and stem vegetables, which are frequently sold at community service centers. A cocktail of non-pathogenic E. coli and enterohaemorrhagic E. coli (E. coli O157:H7) was used to artificially contaminate the vegetables (initial numbers of bacteria 7-8 log CFU/g). The contaminated vegetables were soaked in sodium hypochlorite for 5 min and then washed three times with running water. After the treatment, number of viable bacterial cells on the vegetables was estimated. Sodium hypochlorite treatment reduced the E. coli population by 1-2 log CFU/g on leafy green and stem vegetables, a significant reduction from the initial number. Further, sodium hypochlorite showed better antimicrobial efficacy for leaves with a larger surface area, less roughness, and softness. There was no significant difference in the antimicrobial effect between 100 and 200 mg/kg of sodium hypochlorite. Therefore, it is not necessary to increase sodium hypochlorite concentration than the level suggested in the school meal hygiene management guidelines. However, sodium hypochlorite treatment is not sufficient to achieve a safe level of microorganisms on leafy green and stem vegetables since they generally have a high abundance of microorganisms on their surface. Thus, an alternative cooking method for fresh leafy green and stem vegetables in summer should be developed to ensure they are safe for consumption.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.195-198
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• 2008

This study was carried out to investigate the potential use of Zanthoxylum schinifolium and Zanthoxylum piperitum A.P. DC. as a source of antimicrobial agents against food borne pathogens. Essential oils of Z. schinifolium and Z. piperitum A.P. DC. were collected by steam distillation and analyzed by GC-MS. The antimicrobial activity of the essential oils was examined using the agar diffusion and micro-dilution assays. The effectiveness of Z. schinifolium essential oil was greater against Bacillus cereus, Staphylococcus aureus, and Vibrio parahaemolyticus than other pathogens, and the minimal inhibitory concentration (MIC) values were 1.25, 2.5, and 1.25, 2.5, and $1.25\;{\mu}g/mL$, respectively. Z. piperitum A.P. DC. essential oil was the most effective against all pathogens tested except for Escherichia coli O157:H7, and the MIC values against B. cereus, Salmonella choleraesuis, and V. parahaemolyticus were 1.25, 2.5, and $1.25\;{\mu}g/mL$, respectively. Limonene, the major component of Z. piperitum A.P. DC. essential oils, had the highest inhibitory activity toward V. parahaemolyticus with a MIC value of $0.15\;{\mu}g/mL$. Meanwhile, citronellal and geranyl acetate, major components of both essential oils, displayed antibacterial activity against only B. cereus with MIC values of 1.25 and $5\;{\mu}g/mL$, respectively. Therefore, these essential oils could be useful as antimicrobial agents against foodborne pathogens.

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.600-608
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• 2016

Purpose: To investigate the antioxidant, physicochemical sensory, and microbial safety qualities of sunsik containing fermented Curcuma longa L. powder. Methods: Quality characteristics of samples were measured using pH, moisture content, crude ash content, color and sensory evaluation. Antioxidant activities of samples were compared using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) cation radical scavenging activities. Microbial safety of samples were tested for Aerobic plate counts, Salmonella spp., Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli O157:H7. Results: The pH of samples was between pH 5.51 and pH 5.64, which was significantly lower than the optimum microbial living range. The DPPH and ABTS radical activities of sunsik containing 0.8% fermented Curcuma longa L. were significantly increased compared to that of the control (p<0.05). In sensory intensities, sunsik containing 0.8% fermented Curcuma longa L. showed significantly (p<0.05) similar savoy aroma and flavor, spicy aroma, spicy hot flavor, sweet flavor, and throat swallowing values to those of the control samples. Samples of sunsik added 0.8% and 1.2% fermented Curcuma longa L. showed significantly similar overall acceptance values to those of the control. All samples tested were found to free of microbes and microbiologically safe according to the food code standards. Conclusion: The sunsik added with 0.8% or 1.2% fermented Curcuma longa L. powder were successfully developed. we conclude that the developed sunsik with the fermented turmeric powder can be potentially high value products in the highly competitive sunsik food industry.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.736-745
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• 1996

Background : It is known that pulmonary rehabilitation improves dyspnea and exercise tolerance in patient with chronic lung disease, although it does not improve pulmonary function. But there is a controversy whether this improvement after pulmonary rehabilitation is due to increased aerobic exercise capacity. We performed this study to evaluate the effect of pulmonary rehabilitation for 6 weeks on the pulmonary function, gas exchange, exercise tolerance and aerobic exercise capacity in patients with chronic lung disease. Methods : Pulmonary rehabilitations including education, muscle strengthening exercise and symptom-Umited aerobic exercise for six weeks, were performed in fourteen patients with chronic lung disease (COPD 11, bronchiectasis 1, IPF 1, sarcoidosis 1 ; mean age $57{\pm}4$ years; male 12, female 2). Pre- and post-rehabilitaion pulmonary function and exercise capacity were compared. Results: 1) Before the rehabilitation, FVC, $FEV_1$ and $FEF_{25-75%}$ of the patients were $71.5{\pm}6.4%$. $40.6{\pm}3.4%$ and $19.3{\pm}3.8%$ of predicted value respectively. TLC, FRC and RV were $130.3{\pm}9.3%$, $157.3{\pm}13.2%$ and $211.1{\pm}23.9%$ predicted respectively. Diffusing capacity and MVV were $59.1{\pm}1.1%$ and $48.6{\pm}6.2%$. These pulmonary functions did not change after pulmonary rehabilitation. 2) In the incremental exercise test using bicycle ergometer, maximum work rale ($57.7{\pm}4.9$) watts vs. $64.8{\pm}6.0$ watts, P=0.036), maximum oxygen consumption ($0.81{\pm}0.07$ L/min vs. $0.96{\mu}0.08$ L/min, P=0.009) and anaerobic threshold ($0.60{\pm}0.06$ L/min vs. $0.76{\mu}0.06$ L/min, P=0.009) were significantly increased after pulmonary rehabilitation. There was no improvement in gas exchange after rehabilitation. 3) Exercise endurances of upper ($4.5{\pm}0.7$ joule vs. $14.8{\pm}2.4$ joule, P<0.001) and lower extremity ($25.4{\pm}5.7$ joule vs. $42.6{\pm}7.7$ joule, P<0.001), and 6 minute walking distance ($392{\pm}35$ meter vs. $459{\pm}33$ meter, P<0.001) were significantly increased after rehabilitation. Maximum inspiratory pressure was also increased after rehabilitation ($68.5{\pm}5.4$ $CmH_2O$ VS. $80.4{\pm}6.4$ $CmH_2O$, P<0.001). Conclusion: The pulmonary rehabilitation for 6 weeks can improve exercise performance in patients with chronic lung disease.