• Food Science and Preservation
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• v.30 no.5
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• pp.868-874
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• 2023

This study aimed to investigate the drying characteristics of Caragana sinica Rehder flowers, which are basic data necessary for increasing utilization. The flowers were harvested in mid-April and dried at different hot-air temperatures (50-90℃), and the physicochemical properties of the dried flowers were analyzed. It was found that the drying rate was proportional to the air temperature. The visual color of dried flowers was relatively strong in green when dried at 50℃, while browning was relatively severe when dried at 90℃. The greenness (-a^* value) of the mechanical color of the powder decreased with increasing temperature, and the yellowness (b^* value) decreased with increasing temperature above 70℃. The soluble solids of the hot water extract were maintained at a certain level after increasing up to 70℃, and the pH decreased with increasing temperature. The total polyphenol contents tended to increase with increasing temperature, and DPPH radical scavenging activity did not show a significant change after increasing up to 70℃. These results suggest that the hot-air drying temperature had a significant effect on the physicochemical characteristics of the C. sinica flower. The appropriate hot-air drying temperature was judged to be less than 50℃ for maintaining the unique color, and approximately 70℃ considering the high hot-water extraction yield and antioxidant capacity.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04a
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• pp.43-43
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• 1999

98년말 동일제지에 도입 설치된 Condebelt 설비는 세계 최초의 대형생산설비로 국제적 인 관심을 모으고 있다. 이러한 첨단 Condebelt 기술의 국산화를 위해서는 국내 원료 특성 에 적합하도록 공정최적화가 요청된다. 본 연구에서는 KOCC를 원료로 이용한 라이너지를 C Conde belt를 이용하여 생산할 경우 주요 공정변수에 따른 물성 변화를 평가하고, 이를 통하 여 Condebelt 공정을 최적화하고자 실험실용 파일로트 건조기를 이용하여 Condebelt 공정의 주요 변수가 지질에 미치는 영향을 검토하였다. 실험용 Condebelt 건조장치의 상부플레이트는 18WC까지, 하부플레이트는 냉각수를 이용 하여 40-80'C까지 조절이 가능하도록 설계하였으며, 유압을 이용하여 압체 압력과 시간을 변화시킬 수 있도록 하였다. 구축된 실험장치를 이용하여 Conde belt 공정의 주요 변수인 온도, 압력, 압체시간, 유입 지필의 건조도 변화에 따른 라이너지의 물성 변화를 평가하고 이를 실린더 건조된 종이의 물성과 비교하였다. 그 결과 본 연구에서 검토된 모든 건조조건에서 Conde belt 건조된 종이가 실린더 건조 된 종이보다 높은 강도를 나타내었으며, 투기저항성과 광택도 역시 향상되었다. 투기저항성 과 광택도는 강도적 성질과 달리 유입지 건조도가 높을수록, 상부플레이트의 온도가 높을수 록 그 효과가 저하되었다. 일반적으로 KOCC를 원료로한 라이너지를 Conde belt로 제조할 경우 상부 고온챔버의 온도를 160'C, 압체압력을 5 bar로 조절하는 것이 가장 좋을 것으로 판단되었다. 원료펄프의 조성에 따른 Condebelt 공정의 건조효과를 연구한 결과 모든 펄프에서 공히 C Condebelt 건조방법이 실린더 건조방법에 비하여 물성 향상 효과가 있는 것으로 나타났으 며, 그 효과는 펼프의 리그닌 함량이 높을수록 크게 나타났다. 또 Condebelt의 물성개선 특 성을 이용한 원료비 절감 가능성을 평가하기 위해 AOCC와 KOCC를 이용하여 단층지와 이 층지를 제조하고 물성을 비교평가하였다. 그 결과 Condebelt를 이용하면 KOCC의 비율을 증가시키더라도 AOCC만을 이용하여 실린더 건조한 종이보다 우수한 물성을 얻을 수 있었다. 이러한 연구를 통하여 Condebelt 공정이 국내 저급원료로 제조된 종이의 강도 저하를 극복할 수 있는 기술임을 확인하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.433-438
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• 2004

This study was conducted to develop a sweet pumpkin to intermediate materials for various processed foods and dried food having high quality. Factorial experiment design with three variables having three levels was adapted and response surface methodology was used to determine optimum conditions for osmotic dehydration of sweet pumpkin. The moisture content, weight reduction, moisture loss and solid gain after osmotic dehydration increased according to increasement of immersion temperature, concentration and time. The effect of concentration was more significant than that of temperature and time at given conditions. Sugar concentration and vitamin C content increased in accordance with increasement of immersion temperature, concentration and time during osmotic dehydration. Hardness was increased by increasing immersion time. The regression models showed very significant values and high correlation coefficients (R2) above 0.91, excepting hardness. The optimum condition for osmotic dehydration was 23$^{\circ}C$, 52$^{\circ}C$Brix and 80 min at the constricted conditions such as 60∼70% moisture content, above 3 mg/100 g vitamin C and more than 10 kg/$\textrm{cm}^2$ hardness.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.349-356
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• 2009

Logs with average diameters of 20~30 cm were dried with microwave to investigate microwave drying characteristic of log and determine the optimal drying conditions. Microwave dryer with output of 20 kW was controlled with respect to the temperature of log during drying. Japanese red pine logs with average diameter of 281.9 mm were dried safely by microwave to below moisture content of 20% within 48 hours. Chinese toon logs showed serious surface checks during microwave drying. Higher drying rates were found with higher initial moisture content.

• Proceedings of the KIEE Conference
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• summer
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• pp.1148-1150
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• 2004

본 논문에서는 $400^{\circ}C$ 이상의 과열 증기발생을 위하여 6kW급 유도가열장치를 개발하여 식품건조 시스템에 적용한 예를 보인다. 유도가열장치는 과열 증기의 온도를 제어하기 위하여 인버터 입력 전압을 $100\sim200V$로 가변제어가 가능하게 하였고, 인버터 입력 전압은 벅컨버터를 사용하여 기준 전압을 과열증기의 온도에 대한 전압 값을 사용하여 제어하였으며, LC 공진에 의해 발생한 전류로 증기 가열 챔버를 유도 가열하여 과열 증기를 발생하게 하였다. 발생한 과열 증기는 식품 건조를 위하여 건조로에 투입되어 고온 건조에서 식품의 건조시간을 단축시킬 수 있었으며, 식품의 손상을 줄일 수 있었다. 이의 검증을 위하여 유도 가열 장치를 설계/제작하여 실험하였으며, 식품 건조 테스트를 행하였다.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.2 s.2
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• pp.93-101
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• 2001

The objective of this study is to derive a shrinkage correction formula that considers temperature effect and to develop a methodology for the improved prediction of the long-term behavior of the FCM bridges by considering seasonal temperature variations in-situ. Thereby, current formulation were performed by using the actual experimental shrinkage data including seasonal temperature variation. The investigation of the long-term behavior of the FCM bridge was performed on the construction site in order to decide applicability of the shrinkage formula Numerical results by the general method indicates inaccurate values of total strain when considering real strain, whereas the applied method demonstrates a good agreement in the resultant strain. In consequently, the applied method will improve the prediction of the long-term deformation of the FCM Bridges.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.251-254
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• 2006

This study was conducted to identify changes of chemical components affected by different drying method and temperature conditions in leaves and stems of peony plant. Drying methods were the dried air heated $(50^{\circ}C)$, far-red ray $(50^{\circ}C)$, room temperature and oven dry $(50^{\circ}C)$. Drying temperature were 40, 50, 60, 70 and $80^{\circ}C$ on far-red ray dryer. Among the drying methods, the contents of components were the highest in far-red drying and normal temperature drying as compared with air heated drying and oven drying. Among the drying temperature conditions, the contents of components were the highest in drying temperature at $40^{\circ}C$ and decreased in high temperature of $70^{\circ}C\;and\;80^{\circ}C$.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.58-66
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• 2016

This study was performed to investigate drying characteristics and quality properties of dried persimmon with vacuum drying process. Drying characteristic curve of the dried persimmon showed that the constant rate drying period and falling rate drying period exist definitely. $_{\circ}Brix$, sugar content and hardness value of the dried persimmon increased as the vacuum pressure and heating temperature increased, but L value of the dried persimmon lower. The results indicated that the optimal conditions were at vacuum pressure of 40~50kPa abs., heating temperature of $30^{\circ}C$ and drying time of 3~4days.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.245-251
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• 2001

This research was conducted to study the changes in physical characteristics of mushrooms (Agaricus bisporus) as influenced by drying methods. Samples were dried using either hot air drying, vacuum drying, or freeze drying and changes in the color, browning index, hardness and rehydration rate were evaluated by response surface methodology. Hot air drying resulted in the fastest drying of sample as compared to other methods. The rate of drying was most affected by the environmental temperature rather than air velocity or vacuum pressure. The overall color difference increased as the temperature and air velocity increased. The overall color changes of the freeze dried samples were minimal as compared to those of fresh mushrooms. The hot air dried samples showed the greatest changes in the overall color, browning index as well as hardness. The freeze dried samples showed the best rehydration characteristic and maintained the best overall quality after drying.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.128-137
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• 1999

In this study, shiitake mushrooms were dried by hot air, vacuum and freeze drying methods and theire physical properties were compared. Since the pore size affects the amount of absorption, the characteristics of water sorption were investigated at various humidities and temperatures. Results showed that the freeze dried product had the greatest pore area and the highest absorption capacity. However, all the dried samples showed similar quality. The browning degrees were severely changed with increased relative humidities and temperatures. Among these drying methods, the freeze drying gave the greatest change in browning degree. The GAB monolayer moisture contents of the dried shiitake mushroom were $5.3{\sim}7.7%$. The prediction model was also provided using parameters such as relative humidity, temperature and pore area.