• 한국식품과학회지
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• 제31권5호
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• pp.1324-1329
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• 1999

국내 유통중인 냉동만두와 피자 중 L. monocytogenes의 분포와 분리균의 특성을 조사하기 위하여 1998년 8월부터 11월에 걸쳐 시료 72개를 구입하여 실험하였다. 전체 냉동식품 중 9.7%(7개)에서 L. monocytogenes가 분리되었으며 냉동만두 중 11.1%,피자 중 5.6%가 오염되어 있었다. USDA와 FDA방법. 그리고 modified cold enrichment 방법 중 USDA방법이 가장 L. monocytogenes의 분리율이 높았으며 분리된 L. monocytogenes 혈청형은 4였다. PCR실험결과 CAMP test와 API Listeria kit를 사용하여 분리된 균주가 L. monocytogenes임이 확인되었다. USDA방법과 PCR을 이용하여 L. monocytogenes를 분리하고 확인하는데 3-4일 정도의 시간이 소요되어 시간을 단축시킬 수 있는 분리 및 확인방법의 개발이 필요하리라 사료된다. 분리된 L. monocytogenes의 내열성을 조사한 결과 tryptic soy broth에서 D값이 $60^{\circ}C$에서 49.2초, $65^{\circ}C$에서 8.8초였으며 냉동식품의 안전한 사용을 위하여 L. monocytogenes의 분리율이 높은 식품에서 D값의 측정이 필요하다고 사료된다.

• 한국미생물·생명공학회지
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• 제19권3호
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• pp.222-227
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• 1991

Rhizobium fredii USDA193은 대두(Peking)의 근모 세포벽에 침투하여 근류를 형성한다. 본 실험에서는 전보 (1)에서 분리 보고한 R.fredii의 pectate lyase 유전자 clone(SY1)으로부터 $\Omega$변이를 시켰다. 이것을 R.fredii USDA193에 다시 marker-exchange시켜 얻은 변이주(R.fredii USDA193$\Omega$와 R.fredii USDA193omega1)의 pectate lyase 활성이 완전히 block되지 못하였다. R.fredii 내에서는 다른 종류의 pel 유전자가 존재하 것으로 생각되며 pelB 및 pelE의 Rhizobium mutants들은 근류형성 초기단계에서 직접적으로 영향을 미치지 못하였다.

• 한국식품위생안전성학회지
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• 제10권2호
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• pp.89-95
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• 1995

Highly lethal Listeria monocytogenes, causing bromatoxism through vegetables, dairy products, meat products and shellfish etc, was examined for possible contamination in market beef. USDA, FDA, Malthus and Modified Cold Enrichment methods were used for the detection of Listeria spp.. Samples of domestic and imported market beef were collected from local meat shopsat Seoul, Korea. Total two hundreds and six of Listeria spp. were isolated and identified from beef. Among 206 isolates, the number of L. welshimeri was one hundred and twenty-one(44.8%). The numbers of isolated L. innocua, L. murrayi, L. monocytogenes, L. grayi, L. seeligeri, and L. ivanovii were 49(18.1%), 14(5.2%), 12(4.4%), 6(2.2%), 2(0.7%), and 2(0.7%), respectively. Detection rates of Listeria spp. varied among four methods. The highest detection rate of Listeria spp. in market beef was found at USDA method and that of L. monocytogenes was found at Malthus method.

• Nutritional Sciences
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• 제6권1호
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• pp.12-19
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• 2003

The measurement of the total antioxidant capacity (TAC) of human plasma has been widely applied in nutritional science, for example to evaluate the antioxidant contribution of dietary components and to study, although indirectly, the bioavailability of dietary antioxidants. Several methods have been proposed for the measurement of TAC, most of them based on the ability of plasma to withstand the oxidative damage induced by aqueous radicals. Although plasma contains both hydrophilic and lipophilic antioxidants that interact through extensive cross-talk in most of the methods employed for the TAC measurement, the hydrophilic antioxidants such as ascorbic acid, uric acid, and protein thiols mainly contribute to the total antioxidant plasma capacity (almost 70%) while lipophilic antioxidants embedded in the lipoproteins (carotenoids, a-tocopherol, ubiquino1-10) participate only in a negligible amount (less than 5%). The present paper reviews the analytical methods used to assess the TAC and in particular focuses on new approaches that are capable of distinguishing the antioxidant capacity of both the aqueous and lipid compartments of plasma. The general principle of the method as well as some in vitro and ex vivo applications will be discussed within the text.

• Journal of Biosystems Engineering
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• 제42권3호
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• pp.227-233
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• 2017

Purpose: Morphological properties of soybean roots are important indicators of the vigor of the seed, which determines the survival rate of the seedlings grown. The current vigor test for soybean seeds is manual measurement with the human eye. This study describes an application of a machine vision technique for rapid measurement of soybean seed vigor to replace the time-consuming and labor-intensive conventional method. Methods: A CCD camera was used to obtain color images of seeds during germination. Image processing techniques were used to obtain root segmentation. The various morphological parameters, such as primary root length, total root length, total surface area, average diameter, and branching points of roots were calculated from a root skeleton image using a customized pixel-based image processing algorithm. Results: The measurement accuracy of the machine vision system ranged from 92.6% to 98.8%, with accuracies of 96.2% for primary root length and 96.4% for total root length, compared to manual measurement. The correlation coefficient for each measurement was 0.999 with a standard error of prediction of 1.16 mm for primary root length and 0.97 mm for total root length. Conclusions: The developed machine vision system showed good performance for the morphological measurement of soybean roots. This image analysis algorithm, combined with a simple color camera, can be used as an alternative to the conventional seed vigor test method.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.954-959
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• 2011

There have been a number of studies conducted in order to compare the efficiencies of recovery rates, utilizing different protocols, for the isolation of L. monocytogenes. However, the severity of multiple cell injury has not been included in these studies. In the current study, L. monocytogenes ATCC 19112 was injured by exposure to extreme temperatures ($60^{\circ}C$ and $-20^{\circ}C$) for a one-step injury, and for a two-step injury the cells were transferred directly from a heat treatment to frozen state to induce a severe cell injury (up to 100% injury). The injured cells were then subjected to the US Food and Drug Administration (FDA), the ISO-11290, and the modified United States Department of Agriculture (mUSDA) protocols, and plated on TSAyeast (0.6% yeast), PALCAM agar, and CHROMAgar Listeria for 24 h or 48 h. The evaluation of the total recovery of injured cells was also calculated based on the costs involved in the preparation of media for each protocol. Results indicate that the mUSDA method is best able to aid the recovery of heat-injured, freeze-injured, and heat-freeze-injured cells and was shown to be the most cost effective for heat-freeze-injured cells.

• 한국가구학회지
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• 제14권2호
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• pp.13-20
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• 2003

This research is to develop kiln-drying schedules for 2.7 mm thick boards of Neolitsea sericea and Dendropanax morbifera, which grow in the southern region of Korean Peninsula. These two species are lesser-known to woodcraft industry in this country. The proper USDA drying schedules for Neolitsea sericea and Dendropanax morbifera were found to be T10-C6 and T10-E6, respectively, by using the Quick Oven-drying Method. The boards dried in a kiln with the newly-developed schedules were revealed to be free from warping and checking.

• Journal of Microbiology and Biotechnology
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• 제19권7호
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• pp.718-726
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• 2009

The objective of this study was to develop and validate secondary models that can predict growth parameters of L. monocytogenes Scott A as a function of concentrations (0-3%) of a commercial potassium lactate (PL) and sodium diacetate (SDA) mixture, pH (5.5-7.0), and temperature (4-37DC). A total of 120 growth curves were fitted to the Baranyi primary model that directly estimates lag time (LT) and specific growth rate (SGR). The effects of the variables on L. monocytogenes Scott A growth kinetics were modeled by response surface analysis using quadratic and cubic polynomial models of the natural logarithm transformation of both LT and SGR. Model performance was evaluated with dependent data and independent data using the prediction bias ($B_f$) and accuracy factors ($A_f$) as well as the acceptable prediction zone method [percentage of relative errors (%RE)]. Comparison of predicted versus observed values of SGR indicated that the cubic model fits better than the quadratic model, particularly at 4 and $10^{\circ}C$. The $B_f$and $A_f$for independent SGR were 1.00 and 1.08 for the cubic model and 1.08 and 1.16 for the quadratic model, respectively. For cubic and quadratic models, the %REs for the independent SGR data were 92.6 and 85.7, respectively. Both quadratic and cubic polynomial models for SGR and LT provided acceptable predictions of L. monocytogenes Scott A growth in the matrix of conditions described in the present study. Model performance can be more accurately evaluated with $B_f$and $A_f$and % RE together.

• 한국토양비료학회지
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• 제32권4호
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• pp.344-356
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• 1999

토양수분 확산계수 추정을 위한 이론식(Mualem's principle)과 실측법(Hopmans' equation)을 제시하여 실험한 결과 실측치와 이론치의 상당한 근접을 보였으므로 Hopmans의 수치해석적 모형을 실측모형으로 재시하고자 한다. 작물계수 측정에 있어서는 생육시기에 따른 모형화보다는 생육온도에 따른 모형화가 함수 관계에 있어서 보다 더 유의성 있는 상관성을 보였다.

• 한국응용곤충학회지
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• 제55권3호
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• pp.285-291
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• 2016

Spathius exarator의 종 그룹에 속하는 S. ibarakius Belokobylskij et Maeto가 한반도에서 알락하늘소(Anoplophora chinensis)의 1령과 2령 유충에 외부기생하는 것으로 확인되었다. 산란유인목을 이용하여 유리알락하늘소와 알락하늘소의 기생봉을 탐색하는 과정에서 이 고치벌이 발견되었다. 이 고치벌의 진단형질과 수컷의 특징, 삽화 및 한반도에 분포하는 종들의 기주목록을 함께 제공하였다.