• 제목/요약/키워드: heating period

검색결과 543건 처리시간 0.022초

불포화 지방산 함유 식물유를 이용한 천연 6-Dodecen-4-oilde (Butter Lactone) 생산을 위한 2-Stage Microbial Biotransformation (Two-Stage Microbial Biotransformation for the Production of 6-Dodecen-4-olide (Butter Lactone) from Plant Oils Containing Unsaturated Fatty Acids)

  • 권순향;김경주;김용휘
    • 미생물학회지
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    • 제43권2호
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    • pp.130-136
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    • 2007
  • 2-단계 미생물 생물전환법을 이용하여 불포화 지방산을 다량 함유하고 있는 식물유로부터 천연 6-dodecen-4-oilde (butter lactone)을 생산하였다. Microbial lipase를 이용하여 식물유에 함유된 불포화 지방산을 분리한 후, Pseudomonas sp. NRRL B-2994의 hydroxylation 기작을 이용하여 광활성의 hydroxyl fatty acid (HFA)로 전환시켰다. Pseudomonas sp.는 불포화지방산linoleic acid를>75% 함유한 홍화유를 48시간의 생물전환공정 과정을 통해 8 g/L의 10-hydroxy-12(z)-octadecenoic acid를 생성하였으며 평균 39.2% 생물전환률을 보였다. 원심 분리된 10-hydroxy-12(z)-octadecenoic acid는 2차적으로 Yarrowia llipolytica ATCC34088의 제한적인 ${\beta}-oxidation$ 기작을 이용하여 4-hydroxy-6-dodecenoic acid로 전환되었다. 배양액 내 존재하는 4-hydroxy-6-dodecenoic acid는 $4N\;H_{2}SO_{4}$를 첨가하여 배양액을 pH 4.0로 낮추고 $100^{\circ}C$에서 5분 동안 가열하여 6-dodecen-4-oilde (butter lactone)으로 lactone화하였다. 천연 6-dodecen-4-oilde는 불포화 lactone으로 기존에 사용된 6-dodecan-4-oilde (dodecalactone) 및 4-decan-4-olide 비교하여 독특한 향 특성을 지니고 있다.

해방(解放) 이후(以後) 가정용(家庭用) 연료재(燃料材)의 대체(代替)가 산림녹화(山林綠化)에 미친 영향(影響) (Impacts of the Substitution of Firewood for Home Use on the Forest Greening after the 1945 Liberation of Korea)

  • 배재수;이기봉
    • 한국산림과학회지
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    • 제95권1호
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    • pp.60-72
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    • 2006
  • 본 논문은 해방 이후 가정용 연료재의 대체와 산림녹화의 연관성을 평가하였다. 해방 이후 1960년대 초반까지 총 입목축적의 약 17%에 해당하는 연간 1천만 $m^3$ 내외의 목재를 가정용 연료재로 소비한 까닭에 우리나라는 심각한 산림황폐화에 직면하게 되었다. 1955년 가정용 연료재의 소비량이 그대로 유지될 경우 10년 내에 전국의 산림이 민둥산이 될 정도로 심각한 상황이었다. 이런 문제를 해결하기 위해 상공부는 국내의 유일한 부존자원인 무연탄을 이용하여 가정용 연료재를 대체하는 에너지정책을 추진하였다. 농림부는 대도시 내 임산연료의 반입을 금지하고 가정용 연료재를 연탄으로 대체하여 나갔다. 이런 정책은 점차 성공을 거두어 1970년에 이미 취사용 연료로 임산연료를 사용하는 도시 가구는 5.2%에 불과하였다. 또한 1970년대 이후 가정용 연료재의 실질적 소비자인 농촌인구가 도시로 급격히 이주함에 따라 연료재 소비량도 자연스럽게 감소하였다. 농촌지역의 취사용 연료재는 1985년 이후 가스로, 난방용 연료재는 1980년 이후 연탄으로 급격히 대체되었다. 결국 가정용 연료재의 대체라는 근본적인 변화가 토대가 되어 지난 1세기 이상 진행된 산림황폐화는 마침내 마침표를 찍게 되었다.

농촌 환경ㆍ건강 지표의 변화 추이(2001~2010년) -농촌 거주 농업종사자와 비농업종사자의 비교- (Changes in Rural Health and Environmental Factors (2001-2010) A Comparison between Agricultural and Nonagricultural Groups)

  • 이승교;황정임;원향례
    • 한국지역사회생활과학회지
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    • 제25권1호
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    • pp.99-111
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    • 2014
  • To verify welfare needs, rural health and environmental factors were compared between agricultural and nonagricultural groups over the past 10 years. Based on a survey of rural life by the Rural Development Administration, whose sample included agricultural (72.8%) and nonagricultural (27.2%) groups, all factors were analyzed using SAS ( 9.3). For rural home heating, the use of oil boilers (77.2%-78.0%) decreased (53.0%-53.7%) over the same period, whereas that of electric boilers increased (21.9% and 13.5% for agricultural and nonagricultural groups, respectively). The joint water- supply increased, and the use of flush toilets (52.4% to 84.5% in the agricultural group and 64.6% to 81.4% in the nonagricultural group) and hot-water bathing was higher in the agricultural group (79% to 92.6%) than in the nonagricultural group (72.2% to 87.6%) at the p<0.001 level. Incineration accounted for the largest portion of household waste until 2006, when it was replaced by other treatment methods such as the pay-per-treatment option (44.4% and 68.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). Garbage disposal in 2001 was mainly burial or animal feed, but separate collection increased in 2010 (42.2% and 64.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). The self-perception of health was lower in the agricultural group than in the nonagricultural group (2.96 to 2.74 on a five-point scale in the agricultural group and 3.07 to 2.98 in the nonagricultural group). Drinking decreased less in the agricultural group (criteria: one point once a week,; 1.48 to 1.20) than in the nonagricultural group (1.13 to 0.80) at p<0.001, and a similar pattern was found for smoking (p<0.001). Health screening decreased in the last 10 years (scoring based one point/1-2 times per year,: 0.94 to 0.64 in the agricultural group and 1.08 to 0.69 in the nonagricultural group;p<0.01). These results indicate that various health and environmental factors were less favorable to farmers except for bathing in comparison to nonagricultural living in the same area. This suggests that people in agriculture are less likely to live and work in favorable environments than those outside the sector and thus indicates a need for more attention to the national health welfare system for farmers for systematic realization.

암반공동 열에너지저장소 주변 암반의 열-수리-역학적 연계거동 분석 (Coupled Thermal-Hydrological-Mechanical Behavior of Rock Mass Surrounding Cavern Thermal Energy Storage)

  • 박정욱;;류동우;신중호;박의섭
    • 터널과지하공간
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    • 제25권2호
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    • pp.155-167
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    • 2015
  • 본 연구에서는 TOUGH2-FLAC3D 연계해석기법을 이용하여 암반공동에 고온의 열에너지를 30년간 저장하는 경우 주변 암반에 야기되는 열-수리-역학적 연계거동을 살펴보았다. 열에너지저장에 따른 암반의 거동 특성 및 환경 영향을 예측하고 이에 대한 제어기준을 수립하기 위한 기초 연구로서, 저장소 주변 암반에서 발생하는 열-수리 흐름과 역학적 거동의 상호작용에 대하여 검토하였다. 기본해석으로서 결정질 암반 내 원통형 공동에$350^{\circ}C$의 대용량 열에너지를 저장하는 경우를 모델링하였으며, 열에너지저장소의 단열성능은 고려하지 않았다. 암반 내 열전달의 주요 메카니즘은 암반의 전도에 의한 것으로 판단되며, 암반의 역학적 거동은 수리적 요소보다는 열적 요소에 지배적인 영향을 받는 것으로 나타났다. 암반과 지하수 가열에 따른 유효응력 재분포 양상과 열팽창으로 인한 암반 변위 및 지표 융기를 검토하였으며, 주변 암반에서의 전단파괴 위험도를 정량적인 수치를 통해 제시하였다. 암반 가열에 따른 열팽창으로 인하여 지표면에서 수 cm의 융기가 발생하였으며, 저장공동 상부에 인장응력이 크게 발달하면서 전단파괴의 위험도가 증가하는 것으로 나타났다.

A Nutritional Evaluation on Whole Cottonseed Removed Germination Ability by Heat-treatment

  • Hahm, Sahng-Wook;Son, Heyin;Baek, Seong-Gwang;Kwon, Hyeok;Kim, Wook;Oh, Young-Kyoon;Son, Yong-Suk
    • 한국초지조사료학회지
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    • 제33권1호
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    • pp.39-44
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    • 2013
  • In Korea, wide spread use of whole cottonseed, which is primarily a GMO plant imported from foreign countries and being fed to animals as raw state, has aroused concern that it may disturb the existing ecology of the country unless dispersion of the seed is under proper control. The objective of this study was to elucidate the changes in various nutritive parameters due to heat treatment and to determine the effective condition for removing germination ability of whole cottonseed (WCS). Of the various temperatures applied (76, 78, 80, 85, $100^{\circ}C$/30 min) $85^{\circ}C$ for 30 min was confirmed to be the lowest temperature treatment which resulted in a complete removal of the germination ability of WCS. Therefore, based on the determined temperature condition ($85^{\circ}C$ 30 min) we tried to examine the changes of various nutritional parameters, including nutrient composition, in vitro digestibilities and ruminal protein degradabilities, comparing raw whole cotton seed (RWCS) and heated whole cotton seed (HWCS). Some changes in amino acid composition were observed with heat treatment of WCS, but these were regarded to originate from the variation in plant quality and seed morphology, which are usually affected by different environmental factors during the vegetation period. As for fatty acid composition, no significant differences were observed to occur during heat treatment. However, WCS heated at $85^{\circ}C$ for 30 min in a circulating oven showed a significant decrease (p<0.05) of in situ rumen degradability in both dry matter (DM) and crude protein (CP), as compared to raw WCS. Overall results obtained in the study indicate that the heating condition used in this study, which was proven to be the most appropriate and economic to remove germination ability of WCS, may also improve the nutritional value of the ruminant with regard to reducing its protein degradability within the rumen.

Thermal Inactivation of Sodium-Habituated Staphylococcus aureus in Ready-to-Heat Sauces

  • Park, Ahreum;Lee, Jinhee;Jeong, Sook-Jin;Hwang, In-Gyun;Lee, Soon-Ho;Cho, Joon-Il;Yoon, Yohan
    • 한국축산식품학회지
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    • 제32권6호
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    • pp.713-717
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    • 2012
  • The objective of this study was to evaluate the effect of sodium habituation on thermal resistance of Staphylococcus aureus in various ready-to-heat (RTH) sauces. The strain mixture of S. aureus strains KACC10768, KACC10778, KACC11596, KACC13236 and NCCP10862 was habituated up to 9% of NaCl. The inocula of NaCl-habituated and non-habituated S. aureus were inoculated in 5 g portions of pork cutlet, meat and Carbonara sauces at 7 Log CFU/g, and the samples were vortexed vigorously. The inoculated samples were then exposed to 60 and $70^{\circ}C$ in a water-bath, and survivals of total bacteria and S. aureus were enumerated on tryptic soy agar and mannitol salt agar, respectively, every 30 min for 120 min. At 60oC, the cell counts of total bacteria and the significant difference in survivals between sodium-habituated and non-habituated S. aureus were observed only in the Carbonara sauce; the tailing effect, which is the period of no reduction of bacterial cell counts, was observed in pork cutlet, meat and Carbonara sauces subjected to $60^{\circ}C$. At $70^{\circ}C$, total bacterial populations and sodium-habituated and non-habituated S. aureus cell counts in meat and Carbonara sauce also significantly decreased (p<0.05) after 30 min of heat treatment, followed by the obvious tailing effect. Sodium-habituated S. aureus cell counts in meat and Carbonara sauces were higher (p<0.05) than those of non-habituated S. aureus at $70^{\circ}C$. The results indicate that sodium habituation of S. aureus cells may increase the thermal resistance of the pathogen in RTH sauces; moreover, heating RTH sauces for a short time before serving may not sufficiently decrease the cell counts of S. aureus, particularly for sodium-habituated strain.

급성일산화탄소중독(急性一酸化炭素中毒)의 신경학적(神經學的) 후유증(後遺症)에 관(關)한 역학적(疫學的) 연구(硏究) (An Epidemiological Study on the Neurological Sequelae of Acute Carbon Monoxide Poisoning)

  • 박병주;조수헌;안윤옥;신영수;윤덕로
    • Journal of Preventive Medicine and Public Health
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    • 제17권1호
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    • pp.5-24
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    • 1984
  • There has been an immense need for elaborate studies on the complications and the neuological sequelae generated by acute carbon monoxide (CO) poisoning which is highly prevalent in Korea due to widespread adoption of the anthracite coal briquette as domestic fuel for heating and for cooking. For this epidemiological study, a total of 444 subjects who received hospital emergency care for acute CO poisoning during the period of March 1982 to February 1983 were randomly selected from the emergency patients's lists of 13 general hospitals in Seoul area. Informations on the neurological sequelae were elucidated by means of home visiting with prearranged questionnaire consisting questions and concise neurological examination. The findings obtained were summarized as follows; 1. The complications were found in 18% of the surveyed and acute decubitus was comprised 67.5% of the complications. 2. The total cumulative incidence of the neurological sequelae was 41.2 per 100 patients and the absolute incidence rate regardless of the duration after poisoning was 40.8%. 3. The incidence of the neurological sequelae was higher in the older age than in the younger and also higher in female than in male. Twice higher incidence was observed in the admitted patients than in the non-admitted patients and the incidence became higher in proportion to the duration of CO exposure, coma and admission. The poorer the consciousness level of patients found, at emergency room and at discharge, the higher the incidence. The incidence of the neurological sequelae by emergency care was higher in hyperbaric oxygen therapy group(51.9%) than in 100% $O_2$ group(38.0%) 4. A total of five variables significantly associated with the occurrence of the neurological sequelae were selected by the stepwise discriminant analysis. The variables were following course of emergency care, age, consciousness level at discharge, admission duration, and consciousness level at emergency room in their sequence of discriminant power. Eight variables were selected as those associated with the degree of the neurological sequelae through the stepwise multiple regression analysis. Of these variables, the acute decubitus alone explained 21.1% of the total variation ana all the eight variables could explain 36.5% of the same. The remaining seven variables listed in the order of their relative importance were: age, consciousness level at discharge, admission duration, coma duration and consciousness level at emergency room. 5. It was postulated that unexpectedly high incidence of the neurological sequelae of the CO poisoning in this epidemiological study was mainly due to the inadequate emergency care and the lack of efficient and sophisticated treatment measure. In the effort to minimize the incidence of grave neurological sequelae of acute CO poisoning, new guidelines for the emergency care and treatment should be pursued with efficient ways.

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산분해 대두 단백질로부터 분리된 Esterase 생성균의 생육 및 효소생성 특성 (Esterase Production and Culture Characteristics of Bacteria Isolated from Acid Hydrolysed Soybean Protein)

  • 오남순
    • Applied Biological Chemistry
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    • 제40권6호
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    • pp.484-489
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    • 1997
  • 산분해 대두 단백질로 부터 식품 보존료인 p-hydroxybenzoic acid butyl ester를 분해하고, esterase 활성을 갖는 균주들을 분리, 동정하여 그들의 생육 및 효소 생성 특징을 조사하였다. 분리된 균주들은 전부 Baillus sp. 로 동정되었으며, specific growth rate는 균주에 따라 $0.844{\sim}1.213\;h^{-1}$였으며, esterase activity 는 Baillus sp. KB8 균주가 222 mU/ml로 대비균주인 B. subtilis ATCC6633의 21 mU/ml보다 10배 높은 활성을 보였으나 p-hydroxybenzoic acid butyl ester 분해 활성도는 $5.4{\sim}8.1\;mU/ml$로 균주에 따른 큰 차이는 볼 수 없었다. Baillus sp. KB8 균주의 배양시 NaCl 첨가는 생육을 저해시키며, esterase의 세포외 축적과 세포내 합성을 억제시키는 것으로 나타났으며, 특히 NaCl 첨가 농도의 증가는 세포외 축적을 더 억제시키는 것으로 나타났다. 플라스크 배양실험 결과 Baillus sp. KB8 균주의 효소 생성은 생육이 stationary phase 이후 점차 증가하여 배양 64시간에 420 mU/ml를 생성하였다. 온도에 대한 esterase의 활성은 $50^{\circ}C$에서 30분간 실활없이 유지되었으나 $70^{\circ}C$에서는 전부 실활되었다. $60^{\circ}C$$65^{\circ}C$ 에서의 효소 활성은 노출 시간에 따라 지수적인 실활 경향을 보여 3시간 후 $60^{\circ}C$에서 76%, $65^{\circ}C$에서는 3%의 잔존 효소활성을 보였다.

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참굴, Crassostrea gigas의 생식주기와 성 성숙 유도 (Reproductive Cycle and Induced Sexual Maturation of the Pacific Oyster, Crassostrea gigas)

  • 민광식;김봉석;김태익;허영백;정의영
    • 한국패류학회지
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    • 제20권1호
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    • pp.75-84
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    • 2004
  • Reproductive cycle, the condition index, sex ratio of the Pacific oysters, Crassostrea gigas were investigated by histological and morphometric data. The specimens were collected in the two oyster farms of Geoje and Namhae, Gyeongsangnam-do, Korea, from November 1995 to October 1996. Growth of shell length in two regions was similar, but growth of total weight of the oyster in Namhae was faster than that in Geoje oyster farm. The spawning periods in female and male clams were from July to October in Geoje and from June to October in Namhae oyster farm. Ripe oocytes were approximately 50 m in diameter. The reproductive cycle of in females and males in Geoje and Namhae oyster farms can be divided into five successive stages: early developing, late developing, ripe, partially spawned and spent/inactive. Monthly changes in gonad developmental phases showed somewhat different patterns between female and male clams except for the spawning period. On the whole, however, monthly changes in the gonad developmental phases showed a similar pattern in the same sex. The sex ratios of females to males in Geoje and Namhae oyster farms were not significantly different from a 1:1 sex ratio ($x^2$ = 0.55 (p > 0.05) in Geoje and $x^2$ = 0.27 ( p > 0.05) in Namhae). Artificial induction of maturation by heating of adult oysters (two-year-old) was investigated from 17 January to 18 March in 1996. Maturity at the fixed water temperature group of $20^{\circ}C$ was 80%, it showed the highest maturity of experimental groups cultured for five weeks. The survival (%) of Crassostrea gigas in the raised water temperature experimental groups (15, 20, $25^{\circ}C$) were over 98.5%, as similar to the control group (100%). But, the survival of C. gigas in the fixed water temperature experimental groups (15, 20, 25, $30^{\circ}C$) were decreased with the increase of the water temperatures. In the fixed water temperature experimental group of $30^{\circ}C$, the survival was 51.1%. Base on these results, the fixed water temperature of $20^{\circ}C$ was the best condition for artificial induction of sexual maturation.

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우렁이 생체 및 가공제품의 저장안정성 조사 (Preservative Safety Analysis of the Fresh Apple Snails and their Processing Products)

  • 오병태;강성원;최성길;허호진;조성환
    • 한국식품저장유통학회지
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    • 제15권3호
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    • pp.340-346
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    • 2008
  • 저장안정성을 검토하여 품질개선방안을 확립하고자, 우렁이 생체 및 반건조 우렁이 제품을 저장하는 기간중, 처리조건별 미생물의 경시적 변화와 관능검사를 실시하였다. 우렁이의 초기 총균수(${\log}_{10}\;CFU/g$)는 5.6으로 나타나 식품가공과 유통을 위해서는 살균처리가 필수적이라고 판단되었다. 염침지농도, 건조온도, 건조시간에 따라 우렁이 생체의 조직감, 수분활성도, 건조 특성에 영향을 크게 미치기 때문에 가공 시에 약 10%의 염농도를 가진 침지액에 침지한 후 냉풍 건조하여 처리하여 저장성이 뛰어난 반건조제품을 제조하였다. 천연 보존제 및 연화제를 첨가하여 진공 포장하여 미생물 검사를 한 결과, 총균수는 거의 나타나지 않았으며 대장균, 효모 및 곰팡이, 호염성 미생물은 검출되지 않았으므로, 가공처리 후 필수적으로 진공 포장을 실시해야 하는 것으로 나타났으며, 천연 식품첨가물의 첨가시 우렁이 중간수분식품의 품질이 크게 향상되었기 때문에, 가공시에는 파인애플 착즙액을 원료 대비 5% 첨가하여 좋은 결과를 얻었다. 본 연구결과 개발된 우렁이 가공품은 우렁이가 함유한 여러 생리활성기능(항산화, 항염 및 간기능 개선)의 건강식품 이미지를 살리면서 우렁이를 주원료로 한 반건조 제품, 통조림, 건강음료, 분말 등 가공품의 품질특성을 부여된 가공제품을 생산할 수 있을 것이다.