• 한국식품과학회지
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• 제42권4호
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• pp.398-406
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• 2010

분자압축탈수 방법을 이용하여 기존의 다른 건조방법보다 우수한 탈수 및 건조된 생강을 얻고자 생강을 이용한 분자압축탈수법에 탈수제(maltodextrin) 첨가량, 탈수시간, 절단 두께를 다르게 한 후 반응표면분석법으로 최적화하여 생강의 탈수 및 건조 최적조건을 얻고자 하였다. 분자압축탈수 방법을 이용한 생강의 탈수제 첨가량을 증가시킬수록 탈수율, 복원율, 관능적 특성의 외관(external), 향기(flavor), 조직감(texture) 및 전체적인 기호도(overall acceptability) 등은 증가하였으나 색(color)의 경우 낮아졌다. 또한 탈수시간, 절단 표면을 증가시킬수록 탈수율, 복원율, 관능적 특성이 증가하는 경향을 나타내었다. 분자압축탈수를 이용한 생강의 최적조건 범위는 탈수제 첨가량이 70-82%, 탈수시간이 5.2-9.2시간 이고 절단 두께가 1.0-1.2 mm로 설정되었다. 따라서 분자 압축탈수 방법을 이용한 생강의 최적 탈수 및 건조조건은 탈수제 첨가량이 76%, 탈수시간 7.2시간, 절단 두께 1.1 mm가 적당한 것으로 나타났다.

• 한국식품저장유통학회지
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• 제17권3호
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• pp.358-364
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• 2010

분자압축 탈수공정에 의한 색도변화는 재사용 탈수액을 적용한 건조공정에서 원물과 유사한 색도를 나타내었다. 수분 및 수분활성도에서도 유의적 경향이 일치하였다. 탈수액의 농도와 첨가량에 의한 탈수율과 복원율의 변화에서는 탈수액의 농도 차이에 따라 탈수율은 달라졌으며 농도가 커질수록 탈수율이 증가하는 경향을 나타내었다. 복원율 역시 탈수액 농도가 낮을수록 완만한 복원율을 나타내었고 탈수액의 농도가 높을수록 복원율이 높았다. 탈수액의 첨가량에 의한 탈수율과 복원율에 변화에서는 첨가량이 다른 탈수제 차이에 따라 탈수율과 복원율이 달라졌으며 첨가량이 커질수록 탈수액 농도와 같이 뚜렷하게 탈수율이 증가하고 복원율이 높게 나타났다. 관능평가를 통하여 탈수액의 농도와 첨가량별 탈수액을 적용하여 분자압축 탈수건조한 생강시료를 비교 하였을 때 모든 항목에서 열풍건조가 가장 낮았고 외관의 경우에서는 동결건조한 시료가 우수하였지만 전체적인 평가에 있어서 탈수액을 이용하여 건조한 생강이 가장 우수하였다. 이 처럼 모든 품질평가 항목의 결과를 통하여 탈수액을 적용한 건조방법이 열풍건조와 동결건조보다 품질이 우수하고 시설과 가격에서 경쟁적으로 우수하며 활용가치와 기존의 건조방법의 단점을 보완해 주는 건조 방법으로 판단이 되어진다.

• 자원리싸이클링
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• 제10권6호
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• pp.43-52
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• 2001

This study was conducted to obtain granular crystalline gypsum that can be used as raw material for Plaster boards or cements from waste Plaster board. Gypsum could be Preferentially disintegrated to gypsum needle in $10\mu\textrm{m}$ or less size by hydration after the dehydration of crushed waste Plaster board. The finer the gypsum needle, it is easier to remove coarse impurities and to recover the gypsum needle. The optimum conditions for obtain the finer gypsum size were dehydration rate of 75~85%, solid concentration at hydration of 10~15%, agitation speed of 250~400 rpm, crushing size before dehydration of 2 cm or less. Gypsum of 98.21% grade was recovered with 99.0% yield as the undersize of 325 mesh wet screening followed by the dehydration-hydration process performed at the conditions of dehydration rate of 80%, solid concentration at hydration of 15%, agitation speed of 300 rpm, crushing size before dehydration of 2 cm or less. After the recrystallization of recovered gypsum, Plate-like gypsum of $151\mu\textrm{m}$ size with 99.49% grade was obtained as the oversize of 270 mesh in a wet screening.

• 한국식품영양과학회지
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• 제27권5호
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• pp.903-907
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• 1998

Mass transfer characteristics during osmotic dehydration of mushrooms(Agaricus bisporus) in sugar solution were studied as a function of sugar concentration, immersion time and temperature, and the effect of osmotic dehydration on browning inhibition of air-dried mushrooms was also evaluated. Increasing the sugar concentration, immersion time and temperature increased moisture loss, sugar gain, molality and rate parameter. The changes of sugar gain and rate parameter were more significantly affected by concentration than by temperature of sugar solutions, while 1$0^{\circ}C$ increase in temperature or 10 Brix increase in concentration had the same effect on water loss. Water loss, sugar gain, molality were rapid in the first period of osmotic dehydration especially in the case of higher concentration and temperature of sugar solutions. Effects of osmotic dehydration in sugar solution(60 Brix, 8$0^{\circ}C$) with 18 min of immersion time(O.D.=0.099) rior to air dehydration on browning inhibition of dried mushrooms were more significant than blanching in water(8$0^{\circ}C$) with the same immersion time(O.D.=0.330) and the control (O.D.=0.559).

• 한국식품영양과학회지
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• 제10권1호
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• pp.53-60
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• 1981

열풍에 의한 표고버섯의 건조현상을 속도론적으로 규명하기 위해서 건조속도를 좌우하는 두 가지 인자에 대해서 그 영향을 고찰한 후 선정된 조건에서 건조곡선 및 건조속도식을 유도하였다. 일정 풍속(1.5m/sec)하에서 온도의 변화$(45{\sim}55^{\circ}C)$를 주었을 때 수분의 감소는 지수함수적으로 감소하였으며 감소율은 온도가 높을수록 더욱 높았다. 온도를 $(45^{\circ}C)$로 고정시키고 풍속의 변화$(1.0{\sim}3.1m/sec)$를 주었을 때 2m/sec까지는 풍속이 빠를수록 건조속도가 높아졌으나, 그 이상의 풍속에서는 오히려 건조속도가 감소하였다. 따라서 풍속은 2m/sec에서 가장 건조속도가 높았다. 선정된 온도 $50^{\circ}C$, 풍속 2m/sec, 습도 38-41%의 조건에서 건조곡선 및 건조속도식을 유도하여 본 결과 $X=6.94e^{-0.345t}$와, $dx/dt=-2.39e^{-0.345t}$라는 Kinetic model 이 얻어졌다.

• Preventive Nutrition and Food Science
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• 제16권3호
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• pp.261-266
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• 2011

Supercritical $CO_2$ pretreatment before dehydration leads to a faster dehydration rate. The best supercritical $CO_2$ pretreatment conditions for the most effective dehydration were $45^{\circ}C$, 25 MPa and $55^{\circ}C$, 25 MPa. Increasing pressure of the supercritical $CO_2$ pretreatment system tended to accelerate the dehydration rate more than increasing temperature did. Samples pretreated at higher temperatures and pressures showed greater shrinking and pore distribution on scanning electron microscopy. Control samples maintained their cell walls, whereas samples pretreated at higher temperatures and pressures showed more cell disruption, and more pores were observed. Pore sizes of control and pretreated samples were about 100 and $70{\sim}80\;{\mu}m$, respectively. Samples pretreated at higher temperatures and pressures had smaller pores and a denser distribution.

• 복식문화연구
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• 제10권5호
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• pp.578-589
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• 2002

The purpose of this research was to analyze the residual water retention and to determine the number and species of microorganisms from the wet cotton fabrics in dehydration and drying process during washing. The drying rates of terrycloth and interlock knit under the rainy seasons were measured according to the dehydration and hanging methods, layers of fabric and pre-treatment agents. Microorganisms were isolated from the dried terrycloth by pure culture, and were identified by Biolog system. The results are as follow: The initial water retention of fabrics after dehydration decreased in the order of dripping>centrifuge>squeezing method, which affected the drying rate. The drying rates were faster by increasing surface area of fabrics. There was no significant difference in drying rate among the fabrics pre-treated with detergent, or fabric softener, or cationic surfactants such as Cetyltrimethylammonium bromide(CTAB) and Benzalkonium chloride(BC). Puedomonas aureginosa was found in the fabrics treated with a powder-type detergent. On the other side, there was no growth of microorganism in the fabrics treated with a liquid-type detergent (containing antibacterial agent), CTAB and BC.

• 한국태양에너지학회 논문집
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• 제23권1호
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• pp.29-38
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• 2003

To develope chemical heat pump using available energy sources, solar heat and other kinds of waste thermal energy, we have studied the material and heat transfer rate in the cylindrical bed reactor packed with Calcined Dolomite. Our results from the studies are as follows ; 1 The time needed to complete dehydration reaction at the wall side of the cylindrical reactor(r/rL=0.5) was shorter than that of the center(r/rL=0.0) as much as 12%. 2. Two dimensional (radial and circumferential) partial differential equations, concerning heat and mass transfer rate in the packed bed of calcined Dolomite, are solved numerically to describe the characteristics of the reaction in the cylindrical reactor. The solution reads rate of reaction in the packed bed reactor depends on the temperature and concentration of reactants. These results read the supplied heat transfers from the wall side of the cylinder to the center, dehydration reaction begins at the inner side of the wall of the cylindrical reactor and the dehydration reaction proceeds from the wall side to center of cylinder.

• Food Science and Biotechnology
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• 제18권1호
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• pp.202-206
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• 2009

Drying characteristics of fresh Korean-type rehmannia (jiwhang) noodle was investigated to determine drying kinetic parameters under the experimental conditions of 5 temperatures (30, 40, 60, 80, and $90^{\circ}C$). Drying curve of the noodle showed a biphasic pattern of decrease in drying rate with initial rapid drying followed by slow dehydration as the progress in drying. In all drying conditions, only falling drying rate period was observed and the drying rate of the noodle was greatly influenced by the drying temperature. The effective diffusion coefficients ($D_{eff}$) were determined by the diffusion model and their temperature dependency was determined using an Arrhenius equation. The activation energy ($E_a$) values for the drying of the noodle were 19.94 and 21.09 kJ/mol at the initial and the latter stage of dehydration, which were comparable to those of pasta or Japanese udong dehydration.

• 한국작물학회지
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• 제49권4호
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• pp.354-357
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• 2004

A simplified technique which cryoprotects zygotic embryos by encapsulation-dehydration was developed for the germplasm conservation of herbaceous peony (Paeonia lactiflora Pall.). The highest survival rate $(85\%)$ was obtained from embryos treated by encapsulation-dehydration. The zygotic embryos were precultured on MS medium containing 0.3mg/L $GA_3$ for 1 day. The precultured embryos were encapsulated in $3\%$ (w/v) alginate beads and immersed for 1 h in MS medium containing 2 M glycerol and 0.5 M sucrose. The encapsulated embryos were dehydrated for 5h by air drying prior to direct immersion in liquid nitrogen. This encapsulation-dehydration method appears to be a promising technique for germplasm cryopreservation of a herbaceous peony.