• Food Science and Biotechnology
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• 제16권1호
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• pp.138-141
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• 2007

The aim of this study was to investigate the effect of irradiation treatment on the inactivation of pathogens in ready-to-use cooked carrot. The pathogens tested were Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, and Listeria inocua. Following the inoculation of these organisms into cooked carrot (about $10^6-10^8\;CFU/g$), the growth of each was inhibited due to irradiation for 24 hr of storage at $20^{\circ}C$. S. typhimurium and E. coli inoculated into cooked carrot were not detected following irradiation with 3 kGy. S. aureus and L. inocua inoculated into the cooked carrot decreased by 5 logs (CFU/g) following 2 kGy irradiation. The range of $D_{10}$ values was from 0.30-0.50. The Hunter color, $L^*-,\;a^*-$, and $b^*-values$, and the hardness of the cooked carrot were not effected by irradiation treatment. The sensory score of irradiated cooked carrot was not statistically different from that of non-irradiated samples (p>0.05). These results indicate that low dose irradiation can enhance the microbial safety and extend the shelf-life of ready-to-eat foods such as cooked carrot.

• 한국환경농학회지
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• 제30권4호
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• pp.459-465
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• 2011

BACKGROUND: Nowadays, Chemical antiseptics have become great problems for health and environmental, so that developing of new substitutes for chemical antiseptics is more and more important. Natural product is a kind of environment-friendly additive that could be used as antiseptic in food industry. Thuja orientalis cv Aurea Nana is a gymnospermous plant of the family Cupressaceae, native to northwestern China and widely naturalised elsewhere in Korea and Japan. This study was aimed to investigate the antibacterial potential of various organic extracts from T. orientalis cones against some food-borne and food-spoilage bacteria. METHODS AND RESULTS: Hexane extract (HE), chloroform extract (CE), ethyl acetate extract (EAE) and methanol extract (ME) were obtained from female cones of T. orientalis. The antibacterial activities of various extracts were tested by standard agar diffusion and minimum inhibitory concentrations (MICs) against five gram-positive and six gram-negative bacteria. Cell viability and morphology change of L. monocytogenes ATCC 10943 treated with hexane extract were also observed. The various extracts displayed remarkable antibacterial effects against all the gram-positive bacteria but did not show any effect against the gram-negative bacteria. Hexane extract has the highest inhibitory effect on cell viability of L. monocytogenes ATCC 10943. SEM observation also demonstrated the damaging effect of the hexane extract on the morphology of L. monocytogenes ATCC 10943 at the minimum inhibitory concentration. CONCLUSION(s): The tested gram-positive bacteria were significantly inhibited by organic extracts of T. orientalis cone. Hexane extract was the most potent against Listeria monocytogenes ATCC 10943, as evidenced by the lowest MIC level and the complete inhibition of cell viability within shortest exposure time, along with SEM observation.

• 한국축산식품학회지
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• 제23권4호
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• pp.342-349
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• 2003

Escherichia coli O157:H7, Staphylococcus aureus와 Salmonella enteritidis는 식품에 의해 전염되는 식품질환성 병원균으로서 세계적으로 알려진 식중독 미생물이다. 오미자 물 추출액 첨가 drink yoghurt에 오염된 식중독 유발균인 Esc. coli O157：H7, Sta. aureus와 Sal. enteritidis의 생존에 미치는 영향을 연구하였다. 오미자 물 추출액이 식중독 유발균에 대한생육 저해 활성을 검토하였고, 시험 균주의 최종 균체 농도가 $10^{5}$ CFU/mL 수준이 되도록 오미자 물 추출액 첨가 drink yoghurt에 Esc. coli O157：H7, Sta. aureus와 Sal. enteritidis를 각각 접종하여 37$^{\circ}C$에 배양하면서 시간별로 시험 균주들의 생존 균수를 측정하였다. 시험 결과 시험에 사용된 오미자 물 추출액의 첨가 농도가 증가할수록 모든 시험 균주에서 강한 증식 억제력이 나타났다. 대조구에 비해 오미자 물 추출액 0.4 ,0.6, 0.8과 1.0% 첨가구에서 Esc. coli O157：H7은 각각 0.13, 0.89, 1.99와 2.55의 log cycle 감소 현상을 보였고, Sta. aureus는 각각 0.45, 3.74, 4.13과 5.24의 log cycle이 감소되었으며, Sal. enteritidis는 각각 0.22, 3.44, 4.02와 4.07의 log cycle 감소가 나타나 모든 시험 균주에서 뚜렷한 성장 억제 효과가 관찰되었다. 오미자 물 추출액의 식중독 유발균에 대한 성장 저해 효과는 Sta. aureus, Sal. enteritidis, 그리고 Esc. coli O157：H7의 순으로 강하게 나타났다. 오미자 물 추출액을 0.4, 0.6, 0.8과 1.0% 첨가한 drink yoghurt 내에서 3.55${\times}$$10^{5}$ CFU/mL 수준으로 접종한 Esc. coli O157:H7은 24시간 배양시 1.00${\times}$$10^1$∼3.00${\times}$$10^1$ CFU/mL로 감소되었으며, 48시간 배양하였을 때에는 생육이 완전히 억제되었다. 그리고 1.24${\times}$$10^{5}$ CFU/mL 수준의 Sta. aureus를 접종한 경우 24시간 배양 후 아주 미약한 생존 균수의 감소를 보였으나 48시간 배양시 4.00${\times}$$10^2$∼8.50${\times}$$10^2$ CFU/mL 수준으로 감소하였고, Sal. enteritidis를 1.81${\times}$$10^{5}$ CFU/mL 수준으로 접종한 경우 24시간 배양 후부터 전연 증식을 나타내지 않았다. 이와 같이 오미자 물 추출액 첨가에 의해 drink yoghurt 내에서 식중독 유발균들의 증균 억제 효과를 확인할 수 있었다.할 수 있었다.

• 한국식품위생안전성학회지
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• 제28권1호
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• pp.36-40
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• 2013

본 연구는 기후변화와 관련하여 미생물학적 식품안전상 쉽게 영향 받을 수 있는 식품과 관련 식중독세균을 결정하는데 이용할 수 있는 Risk Ranger를 활용한 Excel spreadsheet 상의 모델을 개발하였고, 모델 입력값은 자료의 부족으로 전문가 설문을 통해 결정하였으며, 확률분포모델과 @RISK를 이용한 시뮬레이션을 통해 실제 국내 식품중 기후변화에 대한 민감할 것으로 예상되는 상위 5개 식품군과 이들 식품과 관련된 주요 식중독 원인균을 결정하였다. 추정결과, 상위 5종 식품과 관련 식중독 세균으로는 즉석섭취식 품류(RTE) (황색포도상구균, 살모넬라, 병원성대장균 O157:H7)가 가장 큰 영향을 받을 것으로 나타났으며, 다음이 떡류 및 빵류 (황색포도상구균, 바실러스 세레우스), 식육 및 알가공품 (살모넬라, 병원성대장균 O157:H7, 황색포도상구균), 두부류 또는 묵류 (바실러스 세레우스, 병원성대장균 O157:H7, 황색포도상구균)였으며, 마지막으로 어육가공품(황색포도상구균, 비브리오, 병원성대장균 O157:H7)의 순으로 나타났다.

• 한국미생물·생명공학회지
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• 제33권1호
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• pp.35-40
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• 2005

본 연구에서는 식중독 유발세균에 대한 항균활성이 우수한 천연 항균성 물질을 검색하기 위해 예로부터 민간과 한방에서 널리 이용되어 온 황금을 각종 유기용매로 추출하여 식중독 유발세균에 대한 항균활성을 조사해 보았다. 황금을 methanol로 추출한 후, petroleum ether, chloroform, ethyl acetate를 이용하여 실온에서 각각 용매별로 계통 분획하고, 열수추출물을 얻은 후, 9종의 식중독 유발세균(Staphylococcus aureus, Bacillus cereus, Salmonella enteritidis, Shigella flexneri, Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aruginosa, Shigella sonnei) 에 대하여 항균효과를 조사하였다. 황금 추i물의 농도별 항균 활성 검색에서는 황금의 ethyl acetate추출물이 가장 큰 항균 효과를 보였으며 S. aureus와 S. dysenteriae가 가장 민감하게 반응하는 균주였다. 황금의 ethyl acetate추출물과 사설초의 ethyl acetate 추출물을 혼합하여 항균력을 측정해 본 결과 두 추출물을 섞어 첨가했을 경우가 단독으로 사용했을 때 보다 상승효과를 나타내었다 또한 황금의 ethyl acetate추출물이 식중독 유발세균의 성장에 미치는 효과를 검정하기 위해 S. aureus및 S. dysenteriae의 배양백에 황금의 ethyl acetate 추물을 각각 5,000 ppm 농도로 첨가했을 때, S. aureus의 생육이 24시간 이상까지 억제됨을 관찰할 수 있었고, S. dysenteriae의 생육도 36시간까지 지연시킬 수 있었다. 이상의 결과 황금의 ethyl acetate추출물은 S. aureus와 S. dysenteriae의 성장을 억제하는 것을 알 수 있었다.

• 한국식품위생안전성학회지
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• 제31권6호
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• pp.406-413
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• 2016

본 연구는 축산식품으로부터 식중독균 검출을 위한 시료 전처리법을 확립하기 위해 전처리용액, 균질화 시간, 시료와 전처리용액의 비율에 따른 회수율을 비교하였다. 이를 위하여 햄, 발효유, 소고기에 E. coli O157:H7, S. aureus, S. Typhimurium를 7.0 log CFU/g로 접종하고 PW, SS, BPD, BPW로 처리하였다. 또한 균질화 시간은 30, 60, 90, 120, 300초, 시료와 전처리용액 비율은 1:2, 1:4, 1:9, 1:19로 각각 처리하였다. 그 결과 발효유와 소고기에서는 BPW로 처리하였을 때 전반적으로 식중독균의 회수율이 높았으나(p < 0.05), 햄의 경우에는 전처리 용액에 따른 유의적 차이는 없다. 전처리용액의 최적 비율은 햄, 발효유, 소고기가 각각 1:9, 1:2, 1:4였으며(p < 0.05), 균질화 시간은 모든 시료에서 120초로 처리했을 때 유의적으로 가장 높은 회수율이 나타났다(p < 0.05). 따라서 선정된 최적 전처리 조건에서 식중독균 회수율을 수행한 결과 모든 시료 및 균종에서 85%이상의 높은 회수율을 보였다. 이상의 결과를 종합해 볼 때 축산식품으로부터 식중독균 검출을 위한 전처리 용액 및 시료와 전처리용액의 비율은 시료의 종류에 따라 적절한 것으로 사용하는 것이 식중독균 검출의 정확성을 높일 수 있을 것으로 판단되어진다.

• 식물병연구
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• 제28권4호
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• pp.195-203
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• 2022

Zea mays, known as maize or corn, is a major staple crop and an important source of energy for humans and animals, thus ensuring global food security. Approximately 9.4% of the loss of total annual corn production is caused by pathogens including fungi, bacteria, and viruses, resulting in economic losses. Although the use of fungicides is one of the most common strategies to control corn diseases, the frequent use of fungicides causes various health problems in humans and animals. In order to overcome this problem, an eco-friendly control strategy has recently emerged as an alternative way. One such eco-friendly control strategy is the use of beneficial microorganisms in the control of plant pathogens. The beneficial microorganisms can control the plant pathogens in various ways, such as spatial competition with plant pathogens, inhibition of fungal or bacterial growth via the production of secondary metabolites or antibiotics, and direct attack to plant pathogens via enzyme activity. Here, we reviewed microorganisms as biocontrol agents against corn diseases.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1227-1231
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• 2004

Campylobacter, one of the emerging foodborne pathogens, is highly adaptable to the external environments by changing its morphology. In the present study, a question of whether the whole-cell antibody would still be effective for its detection even though the morphology of C. jejuni was changed was examined. When microaerophilic C. jejuni was exposed to aerobic conditions for 48 h, its morphological change was detected by confocal laser scanning microscope: Its morphology was confirmed as a spiral-bacilli form in microaerobic condition, however, as a coccoid form with a little spiral-bacilli form, when exposed to aerobic conditions. Also, the expressions of the whole-cell proteins of C. jejuni, and the suppression or induction of newly synthesized proteins in both aerobic and microaerobic conditions were analyzed by two dimensional gel electrophoresis. Additionally, immunoblotting assay with the whole cell antibody for the proteins expressed under the two conditions was performed. It was confirmed that the commercial whole-cell antibody of C. jejuni raised in rabbit was reactive. When analyzed with MALDI- TOF MS, the expressed proteins were confirmed as flagellins. Therefore, even though the morphology changed in aerobic condition, these flagellins were expressed and worked as the eitope proteins, thus making it possible to utilize for the development of an immunosensor for real-time detection of any kind of C. jejuni cell.

• 한국식품위생안전성학회지
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• 제10권3호
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• pp.147-153
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• 1995

The ethanol extract from the root bark of Morus alba showed the strongest antimicrobial activity on the growth of almost all the tested microorganisms which were food-borne pathogens and food-related microorganisms. Therefore, fatty acid composition, amino acid composition and shape change of microorganisms treated with the ethanol extract from the root bark of Morus alba were examined. In effects of treatment with the ethanol extract on the fatty acid compositions of B. subtilis, S. aureus and E. coli, fatty aicd compositions such as hexadecanoic acid (16:0) and octadecanoic acid (18:2) of the tested strains were increased but pentadecanoic acid (15:0) heptadecanoic acid (17:0) and acid (16:1) and octadecenoic acid (18:1) of E. coli were decreased. The ethanol extract did not significantly affect the aminn acid composition of the tested strains. Transmission electron micrographs of microorgani는 treated with the ethanol extract exhibited morphological changes that irregularly contracted cell surface in S. aureus and destructed cell walls in B. subtilis and E. coli.

• 한국약용작물학회지
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• 제28권1호
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• pp.38-46
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• 2020

Background: Although Sancho (Zanthoxylum schinifolium Siebold & Zucc) oil has traditionally been used for its antibiotics properties, there is currently a lack of scientific evidence regarding its biological activities. In this study, we investigated the antimicrobial and antioxidant activities of Sancho oil against food-hazardous microorganisms, phytopathogens, and dermatophytes. Methods and Results: We investiated the antimicrobial activity of Sancho oil against 11 food-hazardous microorganisms, nine phytopathogens, and six dermatophytes. The Sancho oil was found to show the strongest antibacterial activity against Shigella flexneri and Listeria spp. Sancho oil also showed high antifungal activity against plant pathogens, particularly Fusarium oxysporum, and showed antimicrobial activity against dermatophytes such as Trichophyton rubrum, Microsporum canis and Candida albicans. The antioxidant activity of Sancho oil was measured using the DPPH method, and was found to be stronger than that of unrefined oil. Moreover, this activity increased with increasing oil concentration. Conclusions: We found that Sancho oil showed differing antimicrobial activities against food-hazardous microorganisms, dermatophytes, and plant pathogens. The antimicrobial activity spectrum of Sancho oil was not broad and varied among microbial strains. On the basis of our findings, we consider that Sancho oil could be used an antibacterial material for food-borne S. flexneri and Listeria spp., a biopesticide for Fusarium spp., and a treatment for dermatophytes such as T. rubrum.