• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.24-28
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• 2002

Effect of pretreatment processing (peeling time, drying temperature, sample type) on the quality of hot air drying peony roots was investigated. Peony roots were peeled for 0, 10, 20, 30, 60, 90 and 120 minute in the peeling machine after water washing. Sample types were whole or cut (thickness of 3mm). Temperatures of hot air drying were 30, 40, 50 and $60^{\circ}C$ The level of water contents in dried sample was $14{\sim}15%$. Drying time was muth reduced as the peeling time, cutting sample types and higher temperature. Contents of paeoniflorin were maintained highest amount (3.48%) in the non-peeling cut sample dried at $30^{\circ}C$ and lowest amount (2.29%) in the 120min-peeling whole one dried at $60^{\circ}C$. Skin color of dried peony roots was heavily discolored in the sample of non-peeling whole type dried at $60^{\circ}C$ and the color was dark brown $({\Delta}E\;was\;46.1)$. When considering shortening of drying time, preservation of active compounds and maintenance of color, the best pretreatment method of drying in peony roots was non-peeling, cut type processing.

• Food Science and Preservation
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• v.10 no.4
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• pp.476-481
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• 2003

As its high functional properties to be used as medicine or food, the cultivation of Agaricus mushroom has been expanded and iぉ commercialization required better storage methods that can extend its functional and nutritional value for longer period. We selected drying as the most plausible method to meet such requirement, and several drying conditions were investigated to locate the optimum drying condition that can be used to keep the quality of mushroom. Drying temperature of 50$^{\circ}C$, 60$^{\circ}C$, 100$^{\circ}C$ were selected to trace the drying time required to achieve the moisture content of mushrooms less than 10%. The drying temperature at 50$^{\circ}C$ required 29 hrs of drying time, while 100$^{\circ}C$ required only 10 hrs of drying tune. However, their quality characteristics on the following categories, on the degree of browning and color were investigated to find the optimum drying condition. In addition, sensory evaluation was conducted to evaluate the quality of dried mushrooms produced by each drying condition. The browning of the mushroom was evidently increased as the higher drying temperature was used and 50$^{\circ}C$ drying produced the most desirable quality of all in pileus or stipe. The aeon of browning intensified by drying temperature was comparable to the result of whiteness index value, which resulted lower L values as drying temperature increased. and the 50$^{\circ}C$ drying resulted the most highest L values among all drying samples. As the browning and whiteness results implied, the sensory evaluation result gathered from the present research indicated that the 50$^{\circ}C$ drying was the most favorable drying condition by scoring the most highest average scores on flavors, color, appearance, and overall acceptability conducted by the 10 evaluation panels.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.115-115
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• 2017

2013년 국내 시설(비닐, 유리 온실)에서 재배되는 토마토, 풋고추, 파프리카의 생산량은 총 632,315 톤으로 잎, 줄기 등 발생되는 부산물은 수확량의 약 30%에 해당되는 189,695 톤으로 추정되며 대부분 노지에 방치 유실되거나, 소각 처리된다. 본 연구에서는 이처럼 단순 폐기되는 농업폐기물을 재활용한 고형연료 제조에 필요한 건조장치를 개발하고 실험을 통해 그 성능을 확인하고자 하였다. 연구를 위해 건조용량 100 kg/hr인 실험실용 건조기를 제작하였다. 경상남도 진주시 농업기술원 온실에서 재배되는 파프리카, 토마토, 딸기, 가지, 고추 등의 부산물을 실험원료로 사용하였다. 원료성상, 원료이송방식, 송풍량, 건조온도, 건조시간에 따른 부산물 건조특성을 파악하였다. 원료를 비교적 짧게 절단하고 열풍이 배출되는 다공판위를 견인형 컨베어로 이송시키는 형태의 경우 건조실험 결과 세절된 원료에서 추출된 내부 수분이 외부로 유출되어 원료들 사이의 공극을 채워 건조공기가 원료층을 통과하지 못하게 하고, 특히 $100^{\circ}C$ 이상 고온에 노출되는 경우 원료표면에 잔류하는 유출 수분이 건조되면서 막을 형성하여 내부 원료들은 전혀 건조가 되지 못하는 현상이 관측되었다. 이러한 원료내부의 공극형성 불량으로 국부적으로 공기가 통과되는 부분만 집중적으로 급격한 건조가 진행되고 공급된 건조공기 대부분이 이 부분으로 유출되어 효과적인 건조가 전혀 진행되지 못하였다. 피건조물 사이의 공극형성을 위해 원료를 절단하지 않고 수행한 건조실험 결과 건조 풍량 및 온도에 따라 건조속도 및 처리용량이 다르게 나타나는 것을 알 수 있다. 특히 송풍량과 압력을 증가 시킨 건조 결과로 건조 상하층 간 불균일 건조 해소 및 건조속도, 건조능력에서 연구목표 치를 상회하는 결과를 보여준다. 특히 건조공기온도 $150^{\circ}C$ 이하에서 풍량을 증가시켜서 원하는 건조작업 수행이 가능함을 확인할 수 있었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.212-217
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• 2004

To make the germinated buckwheat tea, soluble solid contents, total flavonoid contents and organoleptic properties were investigated under various steaming time and drying temperature. The optimum condition of soluble solid contents were 6.93 min of steaming time and 73.59$^{\circ}C$ of drying temperature. Total flavonoid contents were maximum under the condition of 5.22 min of steaming time and 79.05$^{\circ}C$ of drying temperature. The optimum condition of overall palatability was 6.00 min of steaming time and 77.33$^{\circ}C$ of drying temperature. The optimum ranges of soluble solid contents, total flavonoid contents and overall palatability of the tea were 5.4∼7.0 min of steaming time and 75∼8$0^{\circ}C$ of drying temperature. The values expected in the optimum ranges were also similar to the experimental values.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.466-469
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• 2008

This study examined the effect of drying temperature on the qualitative properties of Chrysanthemum boreale M. flowers. The flower samples were dried in a hot air dryer at $40^{\circ}C$, $50^{\circ}C$, and $60^{\circ}C$, respectively, to attain a $23{\pm}1%$ moisture content. The time required to reach the target moisture content was 8.5-69 hr, and there was a very high negative correlation between log (spending time) and temperature. The Hunter color L- and b-values of the flowers were decreased with increasing drying temperature, whereas the a-value was increased. The volatile compounds contained in the dried flowers were determined by a solid-phase microextraction method. Twelve primary volatile compounds were detected and then quantified based on the GC chromatograms of the samples. The total contents of volatile compounds were increased with increasing drying temperature, and germacrene D and camphor were the main compounds in all samples.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.72-76
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• 1996

Hot air drying of Lentinus edodes was studied using the microcomputer drying system that can control the drying parameters such as air temperature, relative humidity and a weight-loss of water. The physico-chemical properties of dried products were measured in order to investigate the drying characteristics. The mechanism of water movement during air drying of Lentinus edodes closely followed the Page model. That was $M-M_c/M_0-M_c\;=\;\exp\;(-0.275t^{1.154})$ at $50^{\circ}C$ and 20% RH. The free amino acids increased with increased relative humidity. The color and browning degree increased with increased air temperature and relative humidity. The rehydration rate was low when the air temperature and relative humidity were high.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.25-34
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• 2018

This paper presents a heating source of carbon nanofibers for the efficiency and the drying performance of laundry dryer, and focuses on the applicability-evaluation of its source. To design the proposed heating module, experiments were conducted in terms of surface temperature and surface temperature distribution characteristics of carbon nanofiber lamps. The surface temperature of the lamps increased linearly with increment of a current to flow a lamp and revealing the increasing pattern as the length of the ramps is shorter. The proposed heating source was evaluated based on drying efficiency, moisture evaporation rate at laundry, and internal temperature of a drum during drying process. The drying efficiency satisfied a 45% which is specified in KS C 9319. The moisture evaporation rate and the internal temperature of the drum were respectively 98.88% and $61.1^{\circ}C$, which are similar to that of S's company dryer. From the evaluation and actual drying test results, the proposed carbon nanofiber lamp heating module is considered to be applicable as a heat source for laundry dryer in terms of drying efficiency and drying performance. it is possible to obtain a heat source at a high temperature, an excellent calorific value, an improvement in drying performance, and an effect of sterilizing laundry due to the emission of far-infrared rays. In addition to the applicability, the difference of the drying efficiency between the dryers was analyzed in detail based on the power consumption of the heat sources.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.74-84
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• 2005

The objectives of this study was to investigate the improvement of thermal kinetics for disposal of sewage sludge using thermal wind drying. The operational parameters varied are the temperature of $130{\sim}170^{\circ}C$ and evaporation velocity WD. Important parameters effect on thermal kinetics for evaporation of water in sewage sludge studied include the drying time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. The saturation point of water evaporation was observed at the drying time of 60 min in conditions of drying temperature $170^{\circ}C$ and drying time of 120 min by drying temperature $130^{\circ}C$ and WD=0.95 m/s. Operation at drying temperature of $170^{\circ}C$ led to higher rate of evaporation than those 130, $150^{\circ}C$ at WD=1.0 m/s and WD=1.0 m/s was higher than WD=0.5 m/s at drying temperature of $130^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.342-347
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• 2007

Physicochemical properties of onion powder as influenced by drying methods were investigated. Moisture contents of onion powder were 13.29%, 12.99%, and 10.78% for samples dried using hot-air dryer, freeze dryer, and vacuum dryer, respectively. There were no significant differences in crude fat, crude protein, and crude ash content (p>0.05) depending on the drying methods. Samples prepared by freeze drying showed a significantly higher L-value as compared with those prepared by hot-air and vacuum drying (p<0.05). Scanning electron micrographs showed that freeze drying produced smaller particle-sized sample which in turn resulted in the higher porosity of the sample. Freeze dried samples revealed significantly lower degree of rehydration than other samples (p<0.05) probably due to small particle size of the sample. Water solubility of freeze dried sample appeared to be higher than that of other drying methods while the swelling ratio of the same sample appeared to be lower than that of the others. Browning index was significantly lower in samples prepared by freeze drying (p<0.05) but not significantly different between samples dried by hot-air and vacuum drying. Vitamin C content was higher in freeze dried onion powder due to the lower temperature applied to the sample. Freeze dried onion powder contained significantly lower amount of total polyphenol and higher amount of total sugar as compared to other samples (p<0.05).

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.742-746
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• 2013

This study was conducted to investigate the effect of different steaming and drying temperature conditions on the physicochemical characteristics of pumpkin powder. All the samples were steamed for 30 or 60 s and then were dried using hot air at 40, 50, 60, and $70^{\circ}C$. The moisture content decreased with an increase in the hot-air drying temperature, while the soluble solid content and yield increased. The color values, L, a, and b of the pumpkin powder decreased with increasing hot-air drying temperature. The pumpkin powder, which was steamed for 60 s had the highest water absorption and water solubility indexes. The carotenoid content of pumpkin powder was mostly destroyed with the increase in the steaming and drying temperatures. The total sugar and reducing sugar contents increased with increasing steaming and drying temperatures. Thus, the steaming and dehydration temperature conditions influenced the physicochemical characteristics of the pumpkin powder.