• 한국식품과학회지
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• 제35권2호
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• pp.329-333
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• 2003

Fruits of 'Manita', a red pepper cultivar, and 'HL', a cultivar bred for single-harvest, cultivated by direct sowing method were harvested simultaneously. The red fruits were freeze-, sun-, indoor-, hot-air $(65^{\circ}C)$, and excessive hot-air (50% longer time) dried. For Manita. ASTA values of freeze- and indoor-dried red pepper were the highest $(153.6{\sim}168.4)$, and those of sun- and hot air-dried ones were $119.2{\sim}131.5$. Excessive hot-air drying decreased the redness by about $9{\sim}15%$ compared to normal hot-air drying. For HL, ASTA values $(150.3{\sim}171.7)$ of indoor-dried red peppers were much higher than other dried peppers. Red pigment in HL was destroyed easily during sun drying, showing values of only $49.2{\sim}69.2$. By excessive hot-air drying, the redness did not decrease, compared to normal hot-air drying. The organic acid contents of both cultivars were higher in sun- and hot-air-dried ones than freeze- and indoor-dried ones. Copsaicinoid contents of both cultivars decreased up to 22% by excessive hot-air drying compared to normal hot-air drying. Sugar contents were lower in all drying methods other than freeze drying for both cultivars.

• 한국약용작물학회지
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• 제14권1호
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• pp.8-13
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• 2006

삼백초의 유효성분과 선도유지에 적합한 건조방법을 구명하고자 건조방법을 달리하여 건조시킨 후 건조방법별 유효성분 함량과 선도를 조사한 결과를 요약하면 다음과 같다. 1. 건조방법별 건조시간은 양건에 비해 열풍건조와 동결건조시 $88{\sim}93%$ 단축되었다. 건물수율은 동결건조 > 양건 > 열풍건조 순으로 높았고, 건조후 수분 함량은 양건 > 열풍건조 > 동결건조 순으로 높았다. 2. 총페놀성 화합물과 quercetin 관련물질 함량은 동결건조 > 열풍건조 > 양건 순으로 높았으며, 열풍건조후 볶음 또는 건조전 증자 처리를 함으로써 감소되었다. 항산화 활성은 동결건조에서 가장 높았고, 열풍건조와 양건 간에는 차이가 없었으며, 열풍건조후 볶음 또는 건조전 증자 처리를 함으로써 증가하여 총페놀성 화합물과 quercetin 관련물질 함량과는 다른 경향을 보였다. 3. 적색도 (a)는 동결건조 < 열풍건조 < 양건 순으로 낮았다. 4. 열풍건조시 부위별 총페놀성화합물과 quercetin 관련물질 함량은 꽃 > 잎 > 세절 > 줄기 순으로 높았으며, 항산화 활성도 유사한 결과를 나타내었다. 부위별 적색도는 잎 < 세절 < 꽃 < 줄기 순으로 낮았다. 5. 삼백초의 유효성분과 선도유지에 적합한 건조방법은 세절하여 동결건조하거나 잎과 꽃만을 열풍건조하는 것이 효과적이었다.

• Journal of Advanced Marine Engineering and Technology
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• 제26권2호
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• pp.226-232
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• 2002

In tradition, there have been two kinds of drying methods, which are sun drying and artificial drying. The sun drying method which has been adopted traditionally has been replaced by the hot-air drying method which is one of the most general methods of artificial drying, with its simple drying system, low initial cost of drying plant, and easy operating method. But the hot-air drying method has some defects ; (1)much energy loss happens due to the discharge of hot air during the drying process, (2)control of drying rate is not easy on account of changing relative humidity of inlet air for uniform hot air temperature, (3)high temperature of floods in drying process brings about the production of low-grade drying products. Also, the hot-air drying method is inducing environmental and sanitary problems which are resulting from the emission of high temperature and high humidity air, including stick on the drying progress. Vacuum drying technique, whose drying time and 7uantity of exhausting energy is about 1/3 ~1/4 of hot air drying, is very excellent in the drying efficiency. As the results, it took about 20 hours for material to reach about 18% of the final moisture content in order to store products for a long time, from about 470% of the early moisture content at the beginning of drying, and maximum drying rate comes to about $0.35 kg/m^2hr$ at about 350% of the moisture content.

• Journal of Ginseng Research
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• 제33권4호
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• pp.361-366
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• 2009

과열증기 건조처리 후 열풍 건조한 인삼의 건조율이 열풍 건조만으로 건조한 인삼에 비하여 약 40%의 빠른 건조율을 나타내었다. 일반성분의 함량에 있어서 조지방, 조단백질, 조섬유 및 회분 함량의 경우 두처리구간 큰 차이가 없었다. 무기질 및 유리당 함량의 경우에 있어서도 두 처리구간 큰 차이를 나타내지 않았다. 조사포닌 함량의 경우 과열증기 처리 후 열풍건조한 인삼분말의 조사포닌 함량은 5.43% 그리고 열풍건조만 한 인삼분말의 조사포닌 함량은 5.4%로 두시료간 큰 차이가 없었다. 색깔의 경우 적색도를 나타내는 a값에서 과열증기 건조 후 열풍건조 처리한 인삼분말이 열풍건조한 인삼분말에 비하여 약간 높은 결과를 나타내었다. 인삼분말의 미생물 수의 경우 과열증기 건조 후 열풍 건조한 인삼분말이 열풍건조한 인삼분말에 비하여 일반세균 및 효모곰팡이가 약 2 log 정도 감소하였고 대장균군의 경우는 약 1 log 정도 감소한 결과를 나타내었다.

• 한국지열·수열에너지학회논문집
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• 제11권4호
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• pp.22-27
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• 2015

Quality characteristics of Shiitake mushroom using two types of dryers, energy-efficient heat pump hot-air dryer and electric heater hot-air dryer were compared. Energy consumed during drying by heat pump hot-air dryer and electric heater hot-air dryer were 22.8 kWh and 28.9 kWh, respectively. Total polyphenol content of heat pump hot-air dryer and electric heater hot-air dryer after drying were $290.55{\pm}10.56ppm$ and $192.99{\pm}6.53ppm$, respectively. No differences were observed between dryers in reconstitution rate and browning ratio after drying. Also, there were no differences between dryers in color value and ${\Delta}E$ value after drying. Shiitake mushroom drying at $45^{\circ}C$ by heat pump hot-air dryer was proved to be more efficient in energy consumption than by electric heater hot-air dryer.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.183-188
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• 2009

RFID method is a non-contact automatic identification technology, which attaches microchips and antennas to an object in a tag form, to send and process information sent to the network using wireless frequency. Drying and curing process is extremely important which minimizes the resistivity of RFID antennas. This research is about the drying characteristic of conductivity ink, and analyzes and compares the hot-air drying process and infrared drying process. Also, the research was done for the improvement in drying performance by using combined process of hot-air and infrared mechanism. The experiment result shows that the hot-air or infrared drying system used alone cannot meet the required performance in drying printing method using conductivity ink. The combined drying system of hot-air and infrared ray showed resistance low enough in short drying and curing time, and this mechanism makes drying and curing process for mass and continuous production possible on-line.

• 설비공학논문집
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• 제22권12호
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• pp.828-836
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• 2010

The drying is a process that involves coupled and simultaneous heat and mass transfer. When a wet solid is subjected to thermal drying, two processes occur simultaneously. Drying is classified according to heat transfer characteristics in terms of conduction, convection and radiation. In thermal drying, radiation is easier to control than conduction and convection drying and involves a relatively simple structure. In this study, we measured energy consumption, surface hardness of paint and surface gloss with variation of surface temperature of drying materials and drying time. Drying characteristics and energy consumption between heating panels and hot air heating have been presented. The present study shows that a dryer using heating panels is more effective than a hot air dryer from the viewpoint of energy conservation. The hot air dryer, however, was not optimized and more studies on various parameters related to drying will need to be investigated for definite comparison of drying characteristics of the dryers. The result, even if limited, would present the effective availability of paint drying.

• Preventive Nutrition and Food Science
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• 제20권2호
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• pp.143-147
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• 2015

Systematic study of how different drying methods, namely hot-air drying, vacuum-drying, and freeze-drying, affect color, browning index, degree of rehydration, water solubility, and vitamin C content is critical for utilizing pine needle powders (PNP) as a novel ingredient in functional foods. Samples prepared by vacuum-drying showed a significantly higher $L^*$-value, whereas higher $a^*$- and $b^*$-values were detected in the hot-air dried samples (P<0.05). The browning index was significantly higher in samples prepared by vacuum-drying compared to samples prepared by freeze-drying (P<0.05). Freeze-dried PNP exhibited a significantly higher degree of rehydration than hot-air dried samples (P<0.05). Water solubilities of freeze-dried and hot-air dried samples were significantly higher than that of vacuum-dried sample (P<0.05). Vitamin C was less destroyed during freeze-drying compared to hot-air or vacuum-drying (P<0.05). Freeze-dried samples displayed a clear porous structure and appeared to have a bigger space, whereas hot-air dried samples showed lower porosity than vacuum and freeze-dried samples.

• 한국식생활문화학회지
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• 제38권5호
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• pp.356-364
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• 2023

This study compared the physicochemical properties of soybean curd residue and black soybean curd residue produced by hot air-drying and freeze-drying. Regardless of drying method, the crude protein, crude ash, crude fiber contents, pH, L, a, b color values and water soluble index were higher in soybean curd residue, whereas total polyphenol contents and antioxidant activity were higher in black soybean curd residue. Significant differences in water absorption index, oil absorption capacity and emulsion activity were observed between soybean curd residue and black soybean curd residue in freeze-drying. On the other hand, the emulsion stability was not significant difference in both hot-air drying and freeze-drying. The crude protein and crude fiber contents of soybean curd residue were not significant difference between hot-air drying and freeze-drying. Freeze-drying resulted in higher crude ash contents, pH, water absorption index, water soluble index, oil absorption capacity, emulsion activity and emulsion stability than hot-air drying. Hot-air drying have caused significantly higher water contents, water activity, total polyphenol contents and antioxidant activity in soybean curd residue than freeze-drying. In conclusion, soybean type and drying methods affect the physicochemical and quality characteristics of soybean curd residue, which could be important factors in the manufacture of processed foods.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.51-60
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• 1997

We investigated the characteristics of air-and vacuum-drying heated by hot plates for 8~14cm-diameter logs or 6~12cm-thick pillars of Pinus koraiensis. And we evaluated the effects of longitudinal kerf and vacuum drying heated by hot plates. The vacuum drying times from green to 10.9~18.6% MC were 15 days, and these times were one-fifth compared to the air-drying times. The longitudinal kerfing had no significant, effect on drying rates during both air-drying and vacuum drying. But drying defects such as surface checks and V-shaped cracks were effectively prevented during air-drying and vacuum drying by longitudinal kerfing. The vacuum drying was more advantageous than air-drying for preventing of surface checks, end checks and V-shaped cracks, and especially, the vacuum dried pillars with longitudinal kerf were almost free from drying defects. In accelerated weathering conditions the resin did not exude for all specimens.