• 한국식품영양학회지
• /
• 제22권3호
• /
• pp.396-401
• /
• 2009

본 실험은 경기 북부 일부 지역의 계란에서 미생물 오염도를 측정하여 계란의 위생 상태를 파악하고자 하였다. 조사 자료로서는 대형 마트에 유통 중인 계란 중에서 서로 브랜드가 다른 계란을 대상으로 하였다. 계란의 난각에 존재하는 일반 세균수를 측정하였다. 그 결과 $3.4{\times}10^4cfu/m{\ell}$로 상당히 높은 일반 세균수가 검출되었다. 다음으로는 식중독 지수의 중요한 지표가 되는 대장균 및 계란으로 인한 식중독에서 주요 원인 균으로 작용하는 살모넬라균의 오염 여부를 파악한 결과, 한 브랜드의 계란에서 대장균이 검출되었고, 살모넬라균은 검출되지 않았다. 또한 각 브랜드에 계란에서 검출된 세균을 분리 동정 한 결과, Klebsiella pneumoniae, Pseudomonas mendocina, Alcaligenes xylosoxidans, Alcaligenes faecalis, Enterobacter cloacae 등이 분리되었다. 이 세균들 중 일부는 사람에게 병원성을 나타내거나, 면역력이 약한 노약자나 어린이에게 기회감염 또는 병원 내 감염을 일으키기도 하는 것으로 알려졌다. 계란의 난각에서 분리된 대장균의 병원성 여부를 판정하기 위하여, 대장균의 DNA를 분리하여 PCR을 수행한 결과, 병원성 대장균들에서 특이적으로 나타나는 유전자형을 가지고 있지 않는 것으로 밝혀졌다. 위의 결과들을 종합하여 보면, 시중에 유통중인 계란의 난각에서 비록 살모넬라균과 병원성 대장균은 검출되지 않았지만, 사람에게 감염을 일으킬 수 있는 여러 병원성 세균들이 검출됨으로써 계란의 유통 및 판매에 더욱 철저한 위생관리가 필요할 것으로 사료된다.

• 한국식품과학회지
• /
• 제48권1호
• /
• pp.92-95
• /
• 2016

본 연구에서는 건조 쌀에 적합한 가공적성과 세균 저감화를 위하여 백미 찹쌀(동진벼)과 현미 멥쌀(신동진벼)에 초고압 전처리를 하였다. 백미 찹쌀과 현미 멥쌀을 500MPa의 압력 하에서 5분간 초고압 처리하였을 때, 건조 쌀 제조에 있어 중요한 특성인 백미 찹쌀의 찰기와 현미 멥쌀의 경도가 유의적으로 감소하였는데(p<0.05), 이는 초고압 처리법은 백미 찹쌀의 낱알 분리가 힘든 찰진 특성과 현미 멥쌀의 딱딱한 식감을 효과적으로 개선할 수 있다는 점을 확인해 주었다. 쌀 텍스처 단면의 입자를 FE-SEM를 이용하여 관찰한 결과, 초고압 처리한 백미 찹쌀과 현미 멥쌀의 단면의 텍스처가 처리 전보다 부드러워졌음을 확인할 수 있었다. 600MPa의 압력 하에서 5분간 초고압 처리했을 때, 현미 멥쌀에서 생육하는 세균수는 처리 전보다 유의적으로 감소하였지만(p<0.05), 내열성 세균수에는 유의적인 차이가 없었다.

• 산업식품공학
• /
• 제21권1호
• /
• pp.88-92
• /
• 2017

동해안의 특산 수산발효식품 중 가자미밥 식해, 오징어 젓갈, 지누아리 무침 등 총 3종의 수산발효식품에서 233개의 균을 분리하였다. 5종의 주요 식중독 균에 대한 항균활성을 측정한 결과 총 분리균 중 36개(15.5%)가 B. cereus ATCC 14579에 대해 항균활성을 나타내 가장 많은 분리균이 이 지시균을 저해하였다. 그 다음으로 S. aureus KCTC 1916, L. monocytogenes ATCC 15313 순으로 다수의 분리균이 항균활성을 나타냈다. 특히 오징어 젓갈에서 분리한 균주 중 각각 5개(6.0%), 3개(3.6%)가 그람음성 지시균인 E. coli O157:H7 ATCC 43895, Sal. enterica ATCC 4931를 저해하였다. 단백질 가수분해 활성의 경우, 72시간 배양 후, 총 분리균주 중 72개(30.9%)가 활성을 나타냈고, 가장 많은 활성을 나타낸 것은 지누아리 무침 분리균으로 72시간 배양하였을 때 36개(60.0%)가 단백질 가수분해활성을 나타냈다. 본 연구를 통해 수산발효식품에서 분리한 균주가 식중독균을 저해하는 항균물질을 생산한다는 것과 단백질 가수분해 능력을 가진 균주가 존재한다는 것을 알 수 있었다. 활성이 우수한 균주의 확보를 통해 우수 활성균주로부터 천연 항균제를 분리, 적용할 수 있고, 단백질 가수분해활성을 다양한 발효식품 및 더 나아가 저염 수산 발효식품 생산에 활용할 수 있을 것으로 기대된다.

• 한국환경보건학회지
• /
• 제41권6호
• /
• pp.397-404
• /
• 2015

Objectives: The aim of this study is to investigate microbial contamination in the school food service environment for the assessment of microbial food safety. Methods: We collected both swab samples from tables and desks and airborne bacterial samples from an elementary school (School A) and a high school (School B). Heterotrophic plate count, total coliform, Staphylococcus aureus, and Bacillus cereus were measured with selective media to quantify microbial concentration. PCR assay targeting 16S rRNA genes was performed to identify the strains of S. aureus and B. cereus isolated. In addition, we made a food service checklist for the locations to evaluate the food service environment. A Wilcoxon test was employed to examine the differences in microbial concentration between before lunchtime and afterwards. Results: Heterotrophic plate counts showed higher levels after-lunch compared to before-lunch at School B. However, levels of S. aureus were higher in the after-lunch period (p<0.05) in both classrooms and in the cafeteria in School A. B. cereus was only sparsely detected in School B. Several samples from food dining carts were found to be contaminated with bacteria, and facilities associated with food delivery were found to be vulnerable to bacterial contamination. Although microbial concentrations in the air showed little difference between before- and after-lunchtime in the cafeteria in School A, those in classrooms were greater after-lunchtime at both schools. Conclusion: Our results suggested that the microbial safety in schools after lunchtime of concern. Necessary preventive measures such as hygiene education for students and food handlers should be required to minimize microbial contamination during food service processes in schools.

• 한국식품영양과학회지
• /
• 제23권5호
• /
• pp.849-855
• /
• 1994

Actively growin Excherichia coli(KCTC 1039) cells were treated with paraquat (1, 1'-dimethyl-4, 4'-bipyridili-um dichloride) by cultivating them in the presence of 1.0mM paraquat. The treatment was carried out with or without shaking to understand the effect of oxygen on paraquat action to thebacterial superoxide dismutase (SOd). By the treatment with vigorous shaking , population growth of the organism almostly stopped and specific activities of SOD of the cells drastically decreased. On contrast ot it, the herbicide showed only l limited inhibitory action on bacterial growth and SOD activity by stationary treatment. Proteins prepared from parquat-treated cells divided into two peaks by Sephacryl column chormatogrpahy, while proteins from the intact cells formed a single peak. Cytoplasmic proteins and plasma membrane proteins of intact cells formed separated three peaks by Sephadex G-75 column chormatography. respectively. Among them the second peak disappeared by paraquat treatment , while the third peak became more apparent. Fractions from the first and the third peak showed SOD activity. Paraquat was detected from the same fractions.

• 한국식품영양학회지
• /
• 제12권2호
• /
• pp.109-112
• /
• 1999

Aerobic plate counts(APC) gram-negative bacterial counts (GNC) and sensory evaluations on chic-ken carcasses during retail and refrigerated storages (3$\pm$1$^{\circ}C$ and 1$0^{\circ}C$) were evaluated. APC and GNC on whole chicken in retail store after storage of 7 days at 3$\pm$1$^{\circ}C$ increased to 3.11 and 3.89 log units com-pared to the initial controls. APC and GNC on whole chicken after storage of 7 days at 1$0^{\circ}C$ increased to 5.43 and 5.03 log units. Sensory scores of chicken carcasses obtained from retail store were in the "liked less" category after storage of 7 days compared to fresh controls. These results indicated that chicken carcasses during refrigerated (1$0^{\circ}C$) storages rapidly allowed the growth of aerobic spoilage bacteria dur-ing storage period which cluld not be microbiologically acceptable after of 7 days of 7 days.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권10호
• /
• pp.1505-1512
• /
• 2005

Bile salt deconjugation is the most biologically significant reaction among the bacterial alterations of bile acids in the gastrointestinal tract of human and animal. The responsible enzyme, bile salt hydrolase (BSH), catalyzes the hydrolysis of glycineand/or taurine-conjugated bile salts into amino acid residues and deconjugated bile acids. Herein we review current knowledge on the distribution of BSH activity among various microorganisms with respect to their biochemical and molecular characteristics. The proposed physiological impact of BSH activity on the host animal as well as on the BSH-producing bacterial cells is discussed. BSH activity of the probiotic strains is examined on the basis of BSH hypothesis, which was proposed to explain cholesterol-lowering effects of probiotics. Finally, the potential applications of BSH research are briefly discussed.

• 한국축산식품학회지
• /
• 제36권4호
• /
• pp.452-457
• /
• 2016

Lactoferrin is a glycoprotein with various biological effects, with antibacterial activity being one of the first effects reported. This glycoprotein suppresses bacterial growth through bacteriostatic or bactericidal action. It also stimulates the growth of certain kinds of bacteria such as lactic acid bacteria and bifidobacteria. In this study, Asn-Leu-Asn-Arg was selected and chemically synthesized based on the partial sequences of bovine lactoferrin tryptic fragments. Synthetic Asn-Leu-Asn-Arg suppressed the growth of Pseudomonas fluorescens, P. syringae and Escherichia coli. P. fluorescens is a major psychrotrophic bacteria found in raw and pasteurized milk, which decreases milk quality. P. syringae is a harmful infectious bacterium that damages plants. However, synthetic Asn-Leu-Asn-Arg did not inhibit the growth of Lactobacillus acidophilus. It is expected that this synthetic peptide would be the first peptide sequence from the bovine lactoferrin C-lobe that shows antibacterial activity.

• 한국식품위생안전성학회지
• /
• 제14권2호
• /
• pp.167-171
• /
• 1999

In order to screen the antagonistic bacteria which inhibit the growth of the apple pathogen, Penicillum expansum, we isolated an effective bacterial strain and investigated into the antifungal activity of the antagonist and it's identification. The eleven strains of bacteria which strongly inhibited P. expansum were isolated from the nature, and the best antagonistic bacterial strain designated as CH142, was selected. The antagonistic strain CH142 was identified to be the genus Bacillus subtilis based on morphological and biochemical characterization. The CH142 showed 55.9% of antifungal activity against the growth of P. expansum. By the treatment of the culture broth and the heat treated culture filtrate of it, the B. subtilis CH142 showed 90% and 15% of antifungal activity, respectively.

• 한국축산식품학회지
• /
• 제23권4호
• /
• pp.361-375
• /
• 2003

In this study, significant factors influencing on the quality and stability of fermented sausage, such as materials, processing conditions, and microbiological characteristics as well as topography during ripening, were documented. Since most fermented sausages are not heated during manufacture or before consumption, a strict control of the growth of pathogens and the selection of favourable conditions that encourage the specific growth and development of desirable microflora are particularly important. With respect to microbiological safety, hurdles, i.e., preservations(nitrite), redox potential, competitive flora, acidity(pH), and water activity($a_{w}$) are matters of importance to prevent proliferation of bacterial pathogens. Today, for ensuring the safety and quality of the final product, the application of starter cultures in combination with the proper processing is subsequently used in practice. For improving the efficiency of microbiological utility in the production of fermented sausages, the understanding of their topography is essential. The documented different points must be taken into account when HACCP systems set up for the manufacture of fermented sausages. There are continuous researches concerning desirable improvements to sausage fermentation with health enhancing properties.