• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.580-585
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• 2004

Respiration of 'Fuyu' persimmon (Diospyros kaki) fruits were measured in terms of oxygen consumption rate and carbon dioxide evolution by closed system experiments at 0, 5, and $20^{\circ}C$. Enzyme kinetics-based respiration model was used to describe respiration rate as function of $O_2\;and\;CO_2$ gas concentrations $(R=V_m[O_2]/K_m+(1+[CO_2]/K_i)[O_2])$, and Arrhenius equation was applied to analyze temperature effect. $V_m\;and\;K_m$ increased, while $K_i$ decreased, with increasing temperature. $K_m\;of\;O_2$ consumption was greater than that of $CO_2$ evolution at equal temperature. Inhibitory effect of reduced $O_2$ level on $O_2$ consumption was more prominent than that on $CO_2$ evolution. Activation energy of respiration decreased with reduced $O_2$ and elevated $CO_2$ concentrations. Activation energy of $CO_2$ evolution was greater than that of $O_2$ consumption. Permeable package experiments verified respiration model parameters by showing good agreement between predicted and experimental gas concentrations in package.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.189.1-189
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• 2003

‘부유’단감은 국내에서는 일반화되어 있는 PE필름 밀봉 저장방식으로 과실의 호흡에 의해 산소농도의 감소와 이산화탄소의 증가로 호흡이 억제되고 이에 따라 노화가 지연됨으로 과실의 저장수명을 증가시키는 방식이며, 최적저장온도는 -0.5~$0^{\circ}C$라고 보고되고 있다. 이에 본 실험에서는 상온유통을 고려하여 2$0^{\circ}C$에서 0.03mm, 0.05mm LDPE필름으로 포장한 경우와 무포장한 경우를 비교하여, 중량, 수소이온농도, 가용성고형분, 경도를 측정하고 이를 외관품질검사 결과와 종합적으로 검토하였으며, 또한 환경기체조성의 범위를 설정하기 위하여 산소농도(1~5%), 이산화탄소농도(5~15%)를 독립변수로 중심합성계획법(central composite design)에 의해 3단계로 부호화하였고 산소소비농도, 이산화탄소 발생속도, pH 당도, 경도를 종속(반응)변수로 결과를 이용하여 독립변수와 종속변수간의 함수관계를 규명하며, 독립변수들의 값의 변화에 따라서 반응량(종속변수)이 어떻게 달라지는 가를 예측하며, 독립변수가 종속변수인 반응량을 최적화(Optimize) 하는가와 어떤 실험계획법을 쓰면 가장 좋은 정도를 얻을 수 있는지를 규명하고자 한다.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.732-739
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• 2013

'Akihime' plums picked at mature stage (50-70% red coloration of the fruit skin) were stored at $1^{\circ}C$ under air or controlled atmosphere (CA) storage regime as following 3% $O_2$ + 1, 3, 5, and 7% $CO_2$ for 50 days for the purpose of assessing the effect of CA storage on the maintenance of fruit quality and the reduction of chilling injury. Fruits stored under CA storage regime showed reduced respiration as well as ethylene production rates compared to the fruits stored in air. Quality attributes including weight loss, Hunter 'a' values, soluble solids content, titratable acidity, and firmness showed smallest changes in fruits stored under CA conditions except for 3% $O_2$ + 7% $CO_2$. High incidence of physiological disorders including chilling injury, flesh browning, and decay were found in fruits stored under both air and CA of 3% $O_2$ + 7% $CO_2$. In our study, the CA storage regime of 3% $O_2$ + 5% $CO_2$ was found the most effective for maintaining overall fruit qualities of 'Akihime' plums produced in Korea, also delayed the development of chilling injury including lack of juiciness and flesh browning. From the results, storage at 3% $O_2$ + 5% $CO_2$ was selected as an optimal condition of 'Akihime' plum for extending storage life up to 50 days at $1^{\circ}C$.

• Analytical Science and Technology
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• v.26 no.6
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• pp.401-406
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• 2013

Oxygen($O_2$) consumption and carbon dioxide($CO_2$) excretion of a fertile chicken egg during incubation were measured by a gas mass spectrometer. A closed sample chamber was developed to collect gas samples during the 20 days of artificial incubation of both a fertile and an infertile egg. After leaving an egg in the sample chamber for an hour, using a gas-tight syringe, samples of 2 mL of gas were collected from the closed sample chamber and analyzed using a gas mass spectrometer in 2~4 day intervals. The $O_2$ consumption and $CO_2$ excretion of chicken embryos increased rapidly after 10 days from the starting point of incubation. After 20 days, 23 mL of $O_2$ was consumed and 16 mL of $CO_2$ was excreted per hour. Throughout the whole period of incubation, concentration of $O_2$ decreased 4.3 mol% and $CO_2$ increased only 3.1 mole%, i.e., the mole of consumed $O_2$ and the mole of excreted $CO_2$ were not the same. On the other hand, during the same period, concentration of $N_2$ increased about 1.3 mol% and the increased mole fraction of $N_2$ was comparable with the difference (1.2 mol%) between the mole fraction of consumed $O_2$ and excreted $CO_2$. Therefore, we can attribute the increase of $N_2$ mole% to the difference of mole fraction between consumed $O_2$ and excreted $CO_2$. In this study, through the analysis of gas, we could explain the respiration of a fertile chicken egg during incubation.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.133.1-133
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• 2003

복숭아는 다른 과일에 비해 조직이 연약하고 저장성이 매우 낮은 여름철 과일이므로 선별, 포장 및 유통과정에 세심한 주의가 필요하다. 따라서 출하.유통시 선도를 유지시켜 유통기한을 연장시킨다면 경제적 효과가 클 것이다. 국내에서 일반화되어 있는 PE필름 밀봉 저장방식은 과실의 호흡에 의해 산소농도의 감소와 이산화탄소의 증가로 호흡이 억제되고, 이에 따라 노화가 지연됨으로 과실의 저장수명을 증가시키는 방식이며, PE필름내 기체조성에 영향을 미치는 요소는 필름의 두께와 저장온도이고 저장온도가 필름의 두께, 즉 MA효과보다 과실연화에 더 큰 영향을 미치는 것으로 알려져 있다. 이는 필름의 두께가 얇을수록 봉지 내 산소농도가 높아져 호흡대사를 촉진하기 때문인 것으로 이해된다. 과육의 연화가 시작되면서 이취를 유발하는 아세트알데히드와 에탄올의 축적이 증가한다고 보고되고 있고 이는 저장고 내 고농도의 이산화탄소 처리 시에 나타난다. 따라서 본 실험에서는 상온 2$0^{\circ}C$에서 복숭아를 0.05mm LDPE필름으로 포장하여 경도, 당도, pH를 측정하였으며 $O_2$(1, 3, 5%), $CO_2$(5, 10, 15%)를 9구분으로 환경기체를 조성하고 중심합성계획법에 의해 반응 표면분석(RSM)을 하였고 갈변도검사 결과와 함께 종합적으로 복숭아저장에 필요한 최적조건을 규명하고자 하였다.

• Food Science and Preservation
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• v.5 no.3
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• pp.207-210
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• 1998

To prolong the shelf life of green chili pepper, packaging films such as 30 $\mu\textrm{m}$ low density polyethylene(LDPE), 20 $\mu\textrm{m}$ perforated polyolefin (SM250), 30 $\mu\textrm{m}$ cast polypropylene (CPP) and 15 $\mu\textrm{m}$ polyolefin (MPD) were used. LDPE showed a suitable gas concentration which consisted of 3-5% O$_2$ and below 5% CO$_2$for keeping quality of green chili peppers after 10 days. Though weight loss was 9.3% for SM250 after 5 days, others showed below 2.0% weight loss after 40 days. Green chili peppers inside CPP package revealed a great decrease in ascorbic acid content after 30 days. SM250 showed a less total microbial count among packages, but there was no great differences among packages.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.343-348
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• 2002

생버섯의 환경기체조절저장을 위한 적정 기체조성을 예측하기 위하여 팽이버섯과 느타리 버섯을 대상으로 호흡특성치를 측정 및 모델링한 결과 두 버섯의 호흡속도는 환경기체조성에 영향을 받는 것으로 나타났다. 버섯의 산소소비속도와 이산화탄소발생속도를 반응표면분석한 결과 느타리버섯의 이산화탄소발생속도를 제외하고는 $R^2$=0.9이상의 높은 상관관계를 나타내었다. 반응표면 분석결과를 이용하여 두 버섯의 적정 기체조성은 팽이버섯의 경우 1~2.5% $O_2$와 10.5-11.5% $CO_2$, 느타리 버섯의 경우에는 2.5~4.5% $O_2$와 11.5~13%$CO_2$가 적정 기체조성 것으로 예측되었으며 일반적인 생버섯의 저장기체조건에 포함되는 농도였다. 따라서 예측된 조건에서 생버섯의 환경기체조절 저장이 가능 할 것으로 판단되었다.

• Membrane Journal
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• v.25 no.5
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• pp.415-421
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• 2015

$SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ oxide was synthesized by solid state reaction method. Dense ceramic membrane was prepared using as-prepared powder by pressing and sintering at $1250^{\circ}C$. XRD result of membrane showed single perovskite structure. The oxygen permeability were measured under 0.21 atm of oxygen partial pressure ($P_{O_2}$) and between 800 and $950^{\circ}C$. The oxygen permeation flux of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ membrane was increased with the increasing temperature. The maximum oxygen permeation flux was $1.839mL/min{\cdot}cm^2$ at $950^{\circ}C$. Long period permeability experiment was carried out to confirm the phase stability and $CO_2$-tolerance of membrane containing Nb in the condition of air with $CO_2$ (500 ppm) as feed stream at $900^{\circ}C$. The phase stability and $CO_2$-tolerance of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ were investigated by XRD and TG analysis. The result of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ which exposed carbon dioxide for 100 hours indicated 8wt% of $SrCO_3$. But it was known that the level of $SrCO_3$ production dose not have a significant effect on oxygen permeability.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.304-309
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• 2002

신선농산물의 호흡에 영향을 미치는 인자를 들면 품목의 종류, 품종, 숙도, 저장온도, 산소농도, 이산화탄소 농도 등이다. 산소농도와 이산화탄소농도는 신선 농산물의 호흡속도에 영향을 주는 외적인 요인으로 분류되며 이들 인자들은 제어하기가 용이하며 모델링을 통하여 함수관계를 도출할 수도 있다. 따라서 환경기체조성을 변화시킨 상태에서 측정된 신선농산물의 호흡속도자료는 포장 및 저장을 위한 중요한 물성특성치로 이용된다. (중략)

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.398-401
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• 2000

The effect of volatile components on cell growth and polysaccharide production in suspension cultures of Aloe saponaria was investigated using an intelligent on-line gas control system which enabled to control the concentrations of oxygen, carbon dioxide and ethylene simultaneously. Aloe production was enhanced in the presence of exogenous ethylene in the concentration range of 5ppm and 15ppm. Maintaining high tension of carbon dioxide (5% v/v) was found to enhance polysaccharide production significantly.