• Title/Summary/Keyword: 냉풍

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Effects of Pretreatment and Drying Methods on Quality and Antioxidant Activities of Dried Jujube (Zizyphus jujuba) Fruit (전처리 조건 및 건조방법에 따른 건조대추의 품질특성 및 항산화 활성)

  • Kim, Jae-Won;Lee, Shin-Ho;No, Hong-Kyoon;Hong, Joo-Heon;Park, Chang-Su;Youn, Kwang-Sup
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.8
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    • pp.1242-1248
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    • 2013
  • This study was performed to determine the effects of pretreatment (NT: non-treatment, BTS: boiling treatment with 3% sodium chloride, DTG: dipping treatment in glycerol) and drying methods (sun drying, hot air drying, and cold air drying) on the physicochemical properties and antioxidant activities of dried jujube (Zizyphus jujuba Mill.) fruits. Our results show that moisture content is lower (P<0.05) with DTG, and that moisture content is lower with hot air drying compared to other drying methods. The bulk density was highest with BTS. The soluble solids content was highest with DTG. Additionally, the soluble solids content were highest in the following order: hot air drying> cold air drying> sun drying. The titratable acidity of hot air drying was highest of all the drying methods. The titratable acidity was higher with NT and DTG, and the brix and acid ratio of sun drying was higher than other drying methods. Among the drying methods, BTS showed the best browning-retarding effect, whereas boiling treatment affected quality and color. The total polyphenol content from hot air drying and NT or DTG treatment was relatively higher than the content from BTS. The flavonoid content was highest with BTS, and all dried jujube showed relatively high antioxidant activities. The sensory evaluation results indicated that the organoleptic scores for overall preference were higher in the NT and DTG treatment groups. These results suggest that pretreatment and drying methods affect the quality of dried jujube fruit, and show that glycerol treatment with hot air drying can be applied to the production of high quality dried jujube.

Comparison of the Physicochemical Properties of Meat and Viscera of Dried Abalone (Haliotis discus hannai) Prepared using Different Drying Methods (건조방법에 따른 건조 전복 (Haliotis discus hannai)의 이화학적 특성 비교)

  • Park, Jeong-Wook;Lee, Young-Jae;Park, In-Bae;Shin, Gung-Won;Jo, Yeong-Cheol;Koh, So-Mi;Kang, Seong-Gook;Kim, Jeong-Mok;Kim, Hae-Seop
    • Food Science and Preservation
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    • v.16 no.5
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    • pp.686-698
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    • 2009
  • We sought basic data for product development and storage improvement of abalone. We explored drying methodologies, such as shade drying, cold air drying, and vacuum freeze drying. We also examined various physicochemical features of both meat and viscera. Raw abalone meat had $78.88{\pm}1.01%$ moisture, $9.24{\pm}0.27%$ crude protein, and $10.05{\pm}0.81%$ carbohydrate (all w/w). The moisture level of dried abalone meat was highest after cold air drying, at $18.38{\pm}0.91%$, and lowest after vacuum freeze drying, at $1.05{\pm}0.05%$. The total amino acid content of raw abalone meat was $17,124.05{\pm}493.18\;mg%$, and fell after shade-drying to $12,969.92{\pm}583.65\;mg%$, and to $13,328.78{\pm}653.11\;mg%$ after cold air drying. The total free amino acid content of raw abalone meat was $4,261.99{\pm}106.55\;mg%$, and rose after shade-drying to $6,336.50{\pm}285.15\;mg%$, to $5,072.04{\pm}248.53\;mg%$ after cold air drying, and to $4,638.85{\pm}218.03\;mg%$ after vacuum freeze drying. The fatty acid proportions in raw abalone meat were $47.00{\pm}0.99%$ saturated, $22.18{\pm}1.05%$ monounsaturated, and $30.82{\pm}1.45%$ polyunsaturated. In the viscera, however, the proportions were $36.72{\pm}0.74%$ saturated, $25.44{\pm}1.12%$ monounsaturated, and $37.84{\pm}1.67%$ polyunsaturated. The contents of chondroitin sulfate in raw abalone were $11.95{\pm}0.35%$ in meat and $7.71{\pm}0.19%$ in viscera (both w/w). After shade-drying, the chondroitin sulfate content was $16.57{\pm}0.90%$ in meat and $9.24{\pm}0.50%$ in viscera. The figures after cold air drying were $16.17{\pm}0.79%$ and $12.44{\pm}0.61%$, and those after vacuum freeze drying $25.17{\pm}1.16%$ and $15.22{\pm}0.70%$ (thus including the highest meat content). The level of collagen in raw abalone was $69.80{\pm}3.07\;mg/g$ in meat and $40.62{\pm}1.79\;mg/g$ in viscera. Meat and viscera dried in the shade had $144.05{\pm}7.78\;mg/g$ and $44.16{\pm}2.39\;mg/g$ collagen, respectively, whereas the figures after cold air drying were $133.29{\pm}6.53\;mg/g$ and $69.20{\pm}3.39\;mg/g$, and after vacuum freeze drying $137.51{\pm}6.33\;mg/g$ and $60.61{\pm}2.79\;mg/g$. Volatile basic nitrogen values of raw abalone showed a higher content in viscera, at $19.01{\pm}0.84\;mg%$, compared to meat ($10.10{\pm}0.44\;mg%$). The value for shade-dried abalone meat was $136.77{\pm}7.37\;mg%$ and that of viscera $197.97{\pm}10.69\;mg%$. After cold air drying the meat and visceral values were $27.32{\pm}1.34\;mg%$ and $71.37{\pm}3.50\;mg%$, respectively.

Physicochemical and Organoleptic Qualities of Sliced-dried Persimmons as Affected by Drying Methods (건조방법을 달리한 감말랭이의 이화학적 및 관능적 품질 특성)

  • Kim, Yeon-Joo;Lee, Su-Jin;Kim, Mi-Yeung;Kim, Gui-Ran;Chung, Hun-Sik;Park, Hyun-Ju;Kim, Mi-Ok;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.41 no.1
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    • pp.64-68
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    • 2009
  • The effects of drying methods (hot air, cold air, vacuum, and infrared drying) on physicochemical and organoleptic qualities of sliced-dried persimmons (Diospyros kaki Thumb. cv. Cheungdobansi) were investigated. The weight of the sliceddried persimmons ranged from 9.30 to 12.01 g, the length from 3.55 to 4.06 cm, the width and thickness were from 3.17 to 3.73 cm and 1.82 to 2.04 cm, respectively. Hot air drying resulted in the highest hardness value as well as Hunter's L, a, and b values. Infrared drying showed the lowest L value and vacuum drying revealed the lowest a and b values. Moisture contents of the sliced-dried persimmons ranged from 38.04 to 46.41%, and soluble solid contents were 42.96-$48.44^{\circ}Bx$. The phenolic compounds and DPPH radical scavenging activity were high for infrared and vacuum drying methods, and all the sliced-dried persimmons showed relatively high antioxidant activities. The sensory evaluation results indicated that the organoleptic scores for the overall preference were high in the order of vacuum > infrared > hot air > cold air drying. These results suggest that the drying methods affected the qualities of the sliced-dried persimmons, showing that vacuum drying is the mast effective among the methods tested for manufacturing the high-quality sliced-dried persimmons.

Evaluation of the Economics of High Speed Machining Considering Environmental Effects (환경영향을 고려한 고속절삭가공의 경제성 평가)

  • Chang, Yoonsang;Kim, Sun-Tae
    • Clean Technology
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    • v.12 no.3
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    • pp.182-189
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    • 2006
  • In this study, high speed machining is evaluated with regard to economical and environmental effects. Considering environmental loads, machining costs are analyzed with the mathematical models of machining economics and cutting fluid loss. Data from the tool life experiments of high speed milling and turning are used for the analysis. The analysis of high speed milling shows that the machining cost decreases as increasing the cutting speed. In turning process, the cooling method using cutting fluid shows the minimum machining cost. Considering both machining and environmental costs, cooling method using cold air is superior to other methods.

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Performance Evaluation of Environmentally Conscious Machining using Super Low Temperature-Cold Air System (초저온 냉풍시스템을 이용한 환경친화적 가공의 성능평가)

  • Bae, J.C.;Lee, S.S.;Kang, M.C.;Kim, J.S.
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.1 no.1
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    • pp.48-54
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    • 2002
  • In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which take environmental aspects into consideration are being developed Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring eqipments under dry and compressed cold air machining.

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Performance Evaluation of Compressed Cold Air System for Environmentally Conscious Machining (환경친화적 가공을 위한 냉풍시스템의 성능평가)

  • 강명창;김정석;이득우;이승상
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.1008-1011
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    • 2002
  • In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which takes environmental aspects into consideration are being developed. Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring equipments under dry and compressed cold air machining.

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Characteristics of Environment-friendly Semi-dry Turning (환경 친화적인 세미드라이 선삭가공 특성)

  • 이종항;오종석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.385-388
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    • 1997
  • As the environmental regulations become stricter, new machining technologies are being developed which takes envi ronmenta 1 aspects into account . Since cut t ing oi I has some impact on environment. many researches are being carried out to minimize the use of cutting oi I. The methods for minimizing cutting oil usage includes the following techniques: I ) Cooling of tools and work piece. 2) Useage of compressed cooling air for the removal of chip. 3) Minimal useage of environment-friendly vegetable cutt:ngoiI for lubrication between chip and tools. Since the turning machine is continuous, tools are under constant thermal load and tool wear increases as the lubricative performance degrades. Also surface roughnesses have a direct influence on turning. In order to examine the characteristics of turningmachining, this work investigates experimentally the degree of tool wear and characteristics of surface roughness in relation to machining conditions, supply methods, and cooling methods.

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Optimal Flow Design of High-Efficiency, Cold-Flow, and Large-size Heat Pump Dryer (히트펌프를 이용한 고효율 냉풍 대형 건조기 유동 최적설계)

  • Park, Sang-Jun;Lee, Young-Lim
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.5
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    • pp.547-552
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    • 2011
  • Drying process, corresponding to a final process in the area of food engineering, requires a lot of heat energy. Thus, the energy efficiency is very important for dryers. Since the energy efficiency of heat pump dryers is much higher compared to that of electric dryers or other types of dryers, most of large-capacity dryers are adopting heat pump. In this study, shapes, positions and number of air-circulating fans, guide vanes, air inlet, outlet and top separator were varied for optimization of the flow of a large-capacity heat pump dryer. In addition, fans were modelled with performance curves and porous media were assumed for foods and heat exchangers. The simulation results were applied to the 12-ton dryer and the velocity distributions were experimentally examined. Finally, uniform drying in time was successfully accomplished through frozen pepper experiment.

Development of the mixed desiccant cooling dryer (복합 냉풍 건조기 개발)

  • Choi, Hyun-Woong;Kim, Young-Il;Park, Seung-Tae;Yoo, Kyung-Rok
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.242-247
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    • 2009
  • The present study has been conducted to reduce the cold air drying rate. According to the cold air drying method, the quality-excellent product could be made and there would be little change of color, taste and smell. As compared with the hot air drying, the cold air drying equipment has the superior dehumidification in a constant drying zone. However, in a falling drying zone that equipment is not energy-efficient because the drying period could be longer by the dehumidificated.

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Study in the Mixed Cooling Dryer Experiment (복합형 냉풍건조기 실험에 대한 검토)

  • Choi, Jin-Young;Kim, Se-Hwan;Park, Seung-Tae;Lee, Jong-Ho
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.254-259
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    • 2009
  • The mixed cooling dryer has been developed significantly by adopting both advantages of cooling dryers and desiccant dryers. In this study, it is introduced that the desired effect, such as drying rate period reduction and energy-saving, could be achieved only by adding the desiccant dryer if an existing cooling dryer is used. The experiment should be conducted for quite long time due to the material selection, so it is regrettable that there are not enough data.

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