• 제목/요약/키워드: chilling effect

검색결과 146건 처리시간 0.034초

Influence of Chilling Duration on Oxygen Consumption and Hatchability in Eggs of the Silkworm, Bombyx mori

  • Yoon, Hyung-Joo;Kim, Sam-Eun;Kim, Jong-Gill;Park, Ji-Young
    • International Journal of Industrial Entomology and Biomaterials
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    • 제8권1호
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    • pp.73-76
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    • 2004
  • The rate of oxygen consumption of the silkworm eggs was measured to set up the barometer for measuring the effect of egg chilling on diapause termination. In diapause eggs, $O_2$ uptake showed a maximum of 79.2 ${mu}ell$/mg eggs/hr, at one day after oviposition and then gradually decreased to 2.2${mu}ell$/mg eggs/hr at 9days. The rates of oxygen uptake of eggs raised immediately after HCl-treatment and reached to a maximal level of 484.5 ${mu}ell$/mg eggs/hr in 9-day-old eggs, which corresponds to 220 fold that of diapause eggs, and the hatching ability was also over 50%. In order to break diapause, eggs incubated at $25^{\circ}C$ for 30 days after oviposition had to be kept at least for 45 days at 5$^{\circ}C$, but chilled eggs for 90 days or longer hatched at 10 days as normal hatching periods. We also investigate periods which the value of $O_2$ uptake of eggs chilled during 15 to 120 days at 5$^{\circ}C$ reached at 200 ${mu}ell$/mg eggs/hr. As a result of that, $O_2$ uptake of eggs chilled during 15 to 45days were not reached at 200 ${mu}ell$/mg eggs/hr and longer the chilling durations are, the higher the rate of $O_2$ uptake is and the longer the chilling durations are, the shorter the periods up to hatching is. And also, hatch-ability increased rapidly as $O_2$ uptake reaches over 20/eggs/hr.

둥굴레의 상배축(上胚軸) 휴면타파(休眠打破)와 유묘생장(幼苗生長)에 대한 지베렐린 및 저온 처리효과 (Effect of Gibberellin and Chilling Treatments on Breaking Epicotyl Dormancy and Seedling Growth of Polygonatum odoratum Druce)

  • 강진호;김동일;배기수;김석현;정종일
    • 한국약용작물학회지
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    • 제7권1호
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    • pp.16-21
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    • 1999
  • 파종부터 유묘출현까지 2년이 소요되는 둥굴레의 종자번식에서 육묘기간을 단축하기 위하여는 우선적으로 적절한 상배축 휴면타파 방법이 설정되어야 할 것이다. 본 시험은 둥굴레의 상배축 휴면타파 방법 을 설정 하고자 $GA_3\;1.0\;mM$을 2일 간격으로 2회 또는 4회 (4일 : 8일) 관주하거나, 4, 6, 8, 12주간 $3^{\circ}C$의 저온처리를 가한 후 유묘 출현과 생장에 관련된 형질을 조사하였던 바 그 결과를 요약하면 다음과 같다. $GA_{3}$ 처리시 자엽(子葉) 파열수(破裂數)는 처리 직후에는 4일 보다 8일 처리에서 높았으나 시간이 경과할수록 처리효과가 소멸된 반면, 상배축 신장이 이루어지지 않아 출현 유묘가 전혀 없었다. 따라서 $GA_3$을 이용한 둥굴레의 상배축 휴면타파는 실험실에서 소규모로 행할 경우는 가능하다고 할지라도 상토를 이용한 다량육묘에서는 적용이 불가능한 것으로 나타났다. 이러한 원인은 $GA_3$ 용액의 관주처리시 자엽초는 파열되나 상배축이 여러 겸의 자엽초로 싸여져 있기 때문에 $GA_3$ 용액에 노출되지 않은 결과로 해석된다. 한편 자엽초 파열과 상배축 신장이 원활히 이루어지는 저온처리는 다량육묘에 이용이 가능하다고 할 수 있다. 그러나 입묘 정도는 저온처리 기간에 의하여 영향을 받는 것으로 나타났는데 적어도 6주의 저온처리가 가하여져야 할 것으로 분석되었다.

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수도의 유묘기 냉해에 관한 연구 III. 유묘의 저온경화 가능성 검토 (Studies on the Chilling Injury of Rice Seedlings III. Possibility of Low-Temperature Hardening)

  • 권용웅;안수봉;오윤진
    • 한국작물학회지
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    • 제24권3호
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    • pp.21-25
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    • 1979
  • 수도 유묘의 내냉성을 증대시키는 방법으로써 저온경화의 가능성과 한계를 구명하고저 품종통일과 진흥을 공시하여 주야간 $30^{\circ}/20^{\circ}$에서 생장한 제3 엽기묘를 6일간 저온경화를 한후 주야간 $8^{\circ}C$ 항온의 저온에 0, 2, 4, 6, 또는 8일간 처리하고 $30^{\circ}$20^{\circ}C 조건에서 냉해를 발현시키므로써 저온경화를 평가하였다. 저온경화방법은 주야간 $30^{\circ}/20^{\circ}C\;생장묘\rightarrow24^{\circ}14^{\circ}C(3일간)\rightarrow18^{\circ}/12^{\circ}C(3일간)\rightarrow8^{\circ}C$ 냉해유발처리의 순서를 갖는 점진적 경화와 $306{\circ}/20^{\circ}C\;생장묘\rightarrow30^{\circ}/20^{\circ}C$, 단 1일 4시간 $8^{\circ}C(2일간)\rightarrow30^{\circ}/20^{\circ}C$, 단 1일 6시간 $8^{\circ}C(2일간)\rightarrow30^{\circ}/20^{\circ}C$, 단 $8^{\circ}C\; 16시간 1회\rightarrow8^{\circ}C$ 냉해유발처리의 단시간 저온의 반복적 경화 2가지 방법이었으며 그 결과는 다음과 같다. 1. 내냉성이 약한 품종 통일은 $8^{\circ}C$ 저온을 4일간 처리하면 경화를 하지 않은 유묘는 묘생존율이 25%에 지나지 않았으나 점전적 경화률은 묘생존율이 59%, 반족적 단시간 경화묘는 묘생존율이 89% 정도로써 저온경화의 효과가 뚜렷하였으나 $8^{\circ}C$ 저온이 6일간 이상이 되면 경화묘들도 묘생존율이 모두 20%이하로 떨어졌다. 2. 내냉성이 강한 품종 진흥은 비경화묘도 $8^{\circ}C$ 저온처리 8일간에서도 묘생존율은 90%이상이어서 묘생존율면에서는 저온경화 효과를 분화시키지 못하였다. 3. $8^{\circ}C$ 저온처리 및 냉해발현후 엽신의 변색고사현상은 품종 통일과 진흥 모두 비경화묘보다는 점진적 경화묘, 그보다는 반복적 단시간 경화묘가 뚜렷하게 정상엽면적비율이 높고 저온경화의 효과가 뚜렷하였다.

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상등급과 등외등급 쇠고기의 기호특성 비교 (Comparison of the Palatability Related with Characteristics of Beef Carcass Grade B2 and D)

  • 문윤희;강세주;현재석;강희곤;정인철
    • 한국식품영양과학회지
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    • 제30권6호
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    • pp.1152-1157
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    • 2001
  • 도축 후 24시간 냉장한 상등급(B2 등급)과 등외등급(D 등급) 쇠고기 지육에서 등심부위를 분할하여 두 쪽으로 나누어 한 쪽은 랩으로 싸서 1일간 냉장하고, 다른 한 쪽은 500g씩 자르고 진공포장하여 30일간 냉장하여 전자는 신선육, 후자는 냉장육이라 하였다. 상등급육과등외등급육의 기호특성을 비교하고 등외등급육의 냉장효과를 알아보기 위하여 신선육과 냉장육의 색도, 연도, ATP 관련물질, 지방산 조성 및 관능평가에 대한 실험을 하였다. 신선육의 경우 상등급육이 등외등급육에 비하여 pH. 젖산함량, 미오글로빈 함량이 낮고 표면색이 우수하였다. 상등급육은 경도와 저작성이 낮으면서 근원섬유 소편화도가 높아 연한 현상을 보였다. 상등급육은 포화지방산 함량이 낮고 단일 불포화지방산에 대한 포화지방산의 비율(MUFA/SFA)과 ATP 함량이 높고, 생육향이 우수하였다. 상등급육은 가열감량 및 가열단축도가 낮은 반면 가열육의 기호성이 현저히 우수하였다. 등외등급육은 상등급육에 비해서 경도, 저작성, 근원섬유 소편화도 및 MUFA/SFA에 대한 냉장효과가 크게 나타났다. 그러나 냉장육의 연도, 가열육 향 그리고 기호성이 등외등급육에 비해 상등급육이 현저히 우수하였다.

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Improvement of Shelf-life and Quality in Fresh-Cut Tomato Slices:

  • Hong Ji Heun
    • 한국식품저장유통학회:학술대회논문집
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    • 한국식품저장유통학회 2004년도 총회및 심포지움
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    • pp.67-72
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    • 2004
  • Quality of fresh-cut tomato slices was compared during cold storage under various modified atmosphere packaging conditions. Chilling injury of slices in containers sealed with Film A was higher than with Film B; these films had oxygen transmission rates of 87.4 and 60.0 ml $h^{-1}\;m^{-2}\;atm^{-1}$ at $5^{\circ}C\;and\;99\%$ RH, respectively. While slices in containers with an initial atmospheric composition of air, $4\%\;CO_2+1\;or\;20\%\;O_2,\;8\%\;CO_2+1\;or\;20\%\;O_2,\;or\;12\%\;CO_2+20\%\;O_2$ showed fungal growth, slices in containers with $12\%\;CO_2+1\%\;O_2$ did not. Low ethylene in containers enhanced chilling injury. Modified atmosphere packaging provided good quality tomato slices with a shelf-life of 2 weeks or more at $5^{\circ}C$. Experiments were conducted to compare changes in quality of slices of red tomato (Lycopersicon esculentum Mill. 'Sunbeam') fruit from plants grown using black polyethylene or hairy vetch mulches under various foliar disease management systems including: no fungicide applications (NF), a disease forecasting model (Tom-Cast), and weekly fungicide applications (WF), during storage at $5^{\circ}C$ under a modified atmosphere. Slices were analyzed for firmness, soluble solids content (SSC), titratable acidity (TA), pH, electrolyte leakage, fungi, yeasts, and chilling injury. With both NF and Tom-Cast fungicide treatments, slices from tomato fruit grown with hairy vetch (Vicia villosa Roth) mulch were firmer than those from tomato fruit grown with black polyethylene mulch after 12 days storage. Ethylene production of slices from fruit grown using hairy vetch mulch under Tom-Cast was about 1.5- and 5-fold higher than that of slices from WF and NF fungicide treatments after 12 days, respectively. The percentage of water-soaked areas (chilling injury) for slices from tomato fruit grown using black polyethylene mulch under NF was over 7-fold that of slices from tomato fruit grown using hairy vetch under Tom-Cast. When stored at $20^{\circ}C$, slices from light-red tomato fruit grown with black polyethylene or hairy vetch mulches both showed a rapid increase in electrolyte leakage beginning 6 hours after slicing. However, slices from tomato fruit grown using the hairy vetch mulch tended to have lower electrolyte leakage than those grown with black polyethylene mulch. These results suggest that tomato fruit from plants grown using hairy vetch mulch may be more suitable for fresh-cut slices than those grown using black polyethylene mulch. Also, use of the disease forecasting model Tom-Cast, which can result in lower fungicide application than is currently used commercially, resulted in high quality fruit for fresh-cut processing. Experiments were conducted to determine if ethylene influences chilling injury, as measured by percentage of slices exhibiting water-soaked areas in fresh-cut tomato slices of 'Mountain Pride' and 'Sunbeam' tomato (Lycopersicon esculentum Mill.). Ethylene concentration in containers without ventilation significantly increased during storage at $5^{\circ}C$, whereas little or no accumulation of ethylene occurred in containers with one or six perforations. Chilling injury was greatest for slices in containers with six perforations, compared to slices in containers with one perforation, and was over 13-fold greater than that of slices in control containers with no perforations. An experiment was also performed to investigate the effectiveness of including an ethylene absorbent pad in containers on subsequent ethylene accumulation and chilling injury. While ethylene in the no-pad controls increased continually during storage of both 'Mountain Pride' and 'Sunbeam' tomatoes at $5^{\circ}C$ under modified atmosphere conditions, no increase in accumulation of ethylene was observed in containers containing ethylene absorbent pads throughout storage. The ethylene absorbent pad treatment resulted in a significantly higher percentage of chilling injury compared with the no-pad control. In studies aimed at inhibiting ethylene production using AVG during storage of slices, the concentration of ethylene in control containers (no AVG) remained at elevated levels throughout storage, compared to containers with slices treated with AVG. Chilling injury in slices treated with AVG was 5-fold greater than that of controls. Further, we tested the effect of ethylene pretreatment of slices on subsequent slice shelf-life and quality. In slices treated with ethylene (0, 0.1, 1, or $10\;{mu}L\;L^{-1}$) immediately after slicing, ethylene production in non-treated controls was greater than that of all other ethylene pre-treatments. However, pretreatment of slices 3 days after slicing resulted in a different pattern of ethylene production during storage. Ihe rate of ethylene production by slices treated with 1 L $L^{-1}$ ethylene 3 days after slicing was greater during storage than any of the other ethylene treatments. With slices pre-treated with ethylene, both immediately and 3 days after slicing, the rate of ethylene production tended to show an negative correlation with chilling injury. Chemical name used: 1-aminoethoxyvinylglycine (AVG).

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Water relations of plants under environmental stresses: role of aquaporins

  • Kang, H.S.;Ahn, S.J.;Hong, S.W.;Chung, G.C.
    • 한국식물생명공학회:학술대회논문집
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    • 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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    • pp.71-80
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    • 2005
  • Effects of low temperature ($8^{\circ}C$) on the hydraulic conductivity of young roots of a chilling-sensitive (cucumber; Cucumis sativus L.) and a chilling-resistant (figleaf gourd; Cucurbita ficifolia Bouche) crop have been measured at the levels of whole root systems (root hydraulic conductivity, $Lp_r$) and of individual cortical cells (cell hydraulic conductivity, Lp). In figleaf gourd, there was a reduction only in hydrostatic $Lp_r$ but not in osmotic $Lp_r$ suggesting that the activity of water channels was not much affected by low root temperature (LRT)treatment in this species. Changes in cell Lp in response to chilling and recovery were similar asroot level, although they were more intense at the root level. Roots of figleaf gourd recovered better from LRT treatment than those of cucumber. In figleaf gourd, recovery (both at the root and cell level) often resulted in Lp and $Lp_r$ values which were even bigger than the original, i.e. there was an overshoot in hydraulic conductivity. These effects were larger forosmotic (representing the cell-to-cell passage of water) than for hydrostatic $Lp_r$. After a short term (1 d) exposure to $8\;^{\circ}C$ followed by 1 d at $20\;^{\circ}C$, hydrostatic $Lp_r$ of cucumber nearly recovered and that of figleaf gourd still remained higher due to the overshoot. On the contrary, osmotic $Lp_r$ and cell Lp in both species remained high by a factor of 3 as compared to the control, possibly due to an increased activity of water channels. After pre-conditioning of roots at LRT, increased hydraulic conductivitywas completely inhibited by $HgCl_2$ at both the root and cell levels. Different from figleaf gourd, recovery from chilling was not complete in cucumber after longer exposure to LRT. It is concluded that at LRT, both changes in the activity of aquaporins and alterations of root anatomy determine the water uptake in both species. To better understand the aquaporin function in plants under various stress conditions, we examined the transgenic Arabidopsisand tobacco plants that constitutively overexpress ArabidopsisPIP1;4 or PIP2;5 under various abiotic stress conditions. No significant differences in growth rates were found between the transgenic and wild-type plants under favorable growth conditions. By contrast, overexpression of PIP1;4 or PIP2;5 had a negative effect on seed germination and seedling growth under drought stress, whereas it had a positive effect under cold stress and no effect under salt stress. Measurement of water transport by cell pressure probe revealed that these observed phenotypes under different stress conditions were closely correlated with the ability of water transport by each aquaporin in the transgenic plants. Together, our results demonstrate that PIP-type aquaporins play roles in seed germination, seedling growth, and stress response of Arabidopsis and tobacco plants under various stress conditions, and emphasize the importance of a single aquaporin-mediated water transport in these cellular processes.

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단감 '부유' 과실의 저장특성에 미치는 수확기 동상해 및 과수원 온도조건의 영향 (Effect of Frost Injury in Harvest Season and Temperature Condition of Orchard on Storage Characteristics of Persimmon (Diospyros kaki 'Fuyu') Fruit)

  • 곽용범;김승희;안광환;이창훈;강성구
    • 현장농수산연구지
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    • 제23권1호
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    • pp.67-80
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    • 2021
  • 단감 '부유'의 가을 동상해 발생과 과실생장에 미치는 식재위치의 표고와 농장의 온도환경의 영향과, 서리가 발생한 과수원의 과실 저장 특성을 알아보고자 경남 창원(과원 A)과 창녕(과원 B)의 경사지 과원에서 표고별(상, 중, 하)로 과실특성을 조사하고 서리가 발생한 후 수확한 과실을 MA저장 후 저장특성(품질, 저온장해)을 조사하였다. 수확기 전후(10월25일, 11월5일, 11월20일)에 조사된 두 과원의 과실의 생장 특성(과중, 당도, 경도)은 표고와 농장 요인의 유의미한 영향을 받지 않았다. 과실 착색은 표고 요인의 영향을 받았으며, 과실의 착색(hunter 'a')은 B 과원보다 A 과원에서 더 빨리 진행되었다. 수확기에 발생한 저온으로 인하여 과원 B의 하부에서만 약 2%의 과실에서 동상해 피해가 관찰되었다. 두 과원(A, B)에서 11월 5일과 11월 20일에 수확한 과실을 저밀도 폴리에틸렌 필름을 사용하여 MA저장 한 결과, 저온지 과원(B)보다 고온지 과원(A)의 과실 경도가 높게 유지되었다. 그리고 11월 5일에 수확한 과실은 약 80일 저장 후에도 건전과율이 과원 A에서 약 73%, 과원 B에서 약 85%로 높게 유지되었으나, 11월 20일(서리 발생 후) 수확한 과실은 A 과원의 과실은 약 80일 저장 후에도 76%의 높은 건전과율을 유지하였으나 B 과원의 과실 건전과율은 약 14%에 불과했다.

Free Amino Acids, Collagen Solubility, and Meat Quality in Pork (Longissimus Muscle of Yorkshire) as a Function of Chiller Temperature and Aging

  • Park, Beom-Young;Park, Kyoung-Mi;Kim, Jin-Hyung;Cho, Soo-Hyun;Kim, Nam-Kuk;Song, Min-Jin;Lee, Chang-Soo;Cho, In-Kyung;Choe, Ho-Sung;Ryu, Kyeong-Seon;Hwang, In-Ho
    • Food Science and Biotechnology
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    • 제17권1호
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    • pp.26-30
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    • 2008
  • This study was conducted to identify the effect of chilling temperature (-3 and $6^{\circ}C$) and aging (1- and 7-day) on objective meat quality, collagen solubility, and free amino acids in pork (longissimus muscle of Yorkshire). Warner-Bratzler (WB)-shear force indicated that variation in chilling temperature had no detectable effect on meat tenderness and tenderization during the 7-day aging period. Among the 13 detected free amino acids, only 3 amino acids (histidine, valine, leucine) were significantly affected by the temperature treatment (p<0.05). Collagen solubility was significantly increased at $6^{\circ}C$ treatment (p<0.05). There was a significant linear relationship (r=0.67, p<0.05) between changes in free amino acids and WB-shear force during the 7-day aging period. These results confirmed that chilling conditions had significantly affected collagen solubility, and meat tenderization occurred in direct proportion to an increase in free amino acids.