• Title/Summary/Keyword: 수분평형

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쌀 품종별 유과제조 특상

  • 신동화;김명곤;정태규;이현유
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.218.2-218
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    • 2003
  • 멥쌀로 동진, 삼강을, 찹쌀로 신선, 한강품종을 선택하여 유과제조실험을 하였다. 사용한 멥쌀의 아밀로오스 함량은 각각 18.5%, 찹쌀은 2-3% 수준이었으며 수침시(12$^{\circ}C$) 2시간 이내에 평형 수분함량에 도달하였고 멥쌀은 30%, 찹쌀은 42%의 수화도를 보였다. 쌀전분의 호화 개시 온도는 64.5-67.5$^{\circ}C$로서 멥쌀과 찹쌀에서 큰 차이가 없었고 유과반데기는 RH 75-84%에서 저장하면 튀김 적정 수분함량인 11-12% 수준에서 유지 가능하였다. 멥쌀과 찹쌀로 유과를 제조, 비교한 결과 멥쌀의 팽화도는 2.5-2.9$m\ell$/g(건물), 찹쌀은 9.1-10.8$m\ell$/g(건물)로 멥쌀이 유의적으로 떨어지고 반대로 경도는 유의적으로 높아졌으며 바삭바삭한 정도는 차이를 보이지 않았다. 비정상 젖산 발효균에 의하여 팽화도, 경도 등은 개선되지 않았고 튀김 기름으로는 콩기름과 미강유간에 차이가 없었다.

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Fixation of Sericin of Silk Fabric by Epoxy Resin (Epoxy수지에 의한 견직물의 Sericin정착)

  • 문영배;남중희
    • Journal of Sericultural and Entomological Science
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    • v.26 no.2
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    • pp.16-25
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    • 1984
  • The sericin fixation of silk fabrics by epoxy resins was studied in the presence of aqueous salt solution in different solvents at the indicated temperature for the desired time. Heavy weight gains were obtained in the reaction with glycerol diglycidyl ether (EX-313) and ethylene glycol diglycidyl ether (EX-810) catalyzed by potassium thiocyanate in such solvents as carbon tetrachloride and p-chloroethylene. The obtained results were summarized as follows; 1) The tested resins were found similar in reaction behavior to silk fabric. The effect of fixation and weight gains was higher in EX-810 than EX-313. 2) The weight gains were increased with reaction time and temperature, and degumming ratio reached a constant value in 90 min at 70$^{\circ}C$. 3) The weight gains and the degumming ratio reached an equilibrium at 3-5% of epoxy concentration. 4) The weight gains were remarkably influenced and increased by the concentration of salt solution. The degumming ratio reached an equilibrium over 0.5N concentration of salt. 5) The weight gains were increased with the dipping time in gently-sloping. The degumming ratio reached an equilibrium over 15 min dipping. 6) The effect of sericin fixation of hydrophobic solvents, such as Carbon Tetrachloride, p-Chloroeth-ylene, Cyclohexane, Xylene and Toluene, was found suitable. 7) The effect of drying temperature was not remarkable on the weight gains and the degumming ratio. 8) There was a slight decrease in the moisture regain of sericin-fixed silk and it may be possible to maintain the moisture regain in the sericin-fixed silk by the epoxy resins. 9) The results on testing physical properties of sericin-fixed silk fabric were as follows; The crease recovery was almost not different from undegummed fabric, but inferior to degummed fabric. The tensile strength was improving in accordance with the effect of sericin fixation, either the elongation did.

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Analysis of Water Balance by Relative Humidity in Closed Transplants Production System (폐쇄형 묘생산 시스템의 상대습도에 따른 수분 수지 분석)

  • 김진국;김용현;최유화;이명규
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2003.04a
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    • pp.58-63
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    • 2003
  • 폐쇄형 묘생산 시스템(closed system for transplants production)은 자연광이 투과되지 않도록 단열재로 구성되어 있어 시스템 내부와 외부의 공기, 물, 열 등의 교환이 기본적으로 제한된다. 또한 식물 생육에 필요한 관수량, 내부에 적절한 습도를 유지시켜 주기 위한 가습량 및 공조기구에 의한 제습량 등이 시스템 내에서 평형을 이루며 순환한다. (중략)

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Water Uptake, Cotyledon Damage after Imbibition and Hypocotyl Elongation in Soybean with Different Seed Size and Color (콩 종실크기 및 종피색에 따른 침종후 수분흡수특성, 자엽손상 및 배축 신장력의 차이)

  • Park, Keum-Yong;Kim, Seok-Dong;Ryu, Yong-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.4
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    • pp.331-338
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    • 1994
  • The experiment was conducted to determine if seed size and seed coat color of soybean might be effective in water uptake and cotyledon damage after imbibition, and hypocotyl elongation. Eight soybean cultivars were separated into two classes of large and small seed based on seed weight, and each class included two cultivars with yellow and black seed color, respectively. Small seed size group was superior in water uptake by seed for 24 hour in imbibition at $25^{\circ}C$ , but its differences decreased as soaking time increased. Small seed cultivars germinated faster and had better germination rate than large ones. However, cultivars with black seed coat showed more slow water uptake at initial time and faster germination than yellow seed, but in 24 hour after imbibition, cultivars with black seed coat had higher water uptake rate than yellow seeds. Small seed cultivar group showed no cotyledon damage in imbibition for 24 hour while large seed cultivars were damaged 78% of cotyledon, and black seed showed low cotyledon damage compared to yellow seed. Hypocotyl length was shorter in large seed rather than in small seed, but hypocotyl thickness in large seed was more thick than in small seed. In correlation coefficients, seed coat rate, embryo rate exhibited significantly negative association with seed weight, and the correlation of seed weight with water uptake in 3 hour after soaking was significantly negative, but in 24 hour showed positive correlation.

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Experimental Retrieval of Soil Moisture for Cropland in South Korea Using Sentinel-1 SAR Data (Sentinel-1 SAR 데이터를 이용한 우리나라 농지의 토양수분 산출 실험)

  • Lee, Soo-Jin;Hong, Sungwook;Cho, Jaeil;Lee, Yang-Won
    • Korean Journal of Remote Sensing
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    • v.33 no.6_1
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    • pp.947-960
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    • 2017
  • Soil moisture plays an important role to affect the Earth's radiative energy balance and water cycle. In general, satellite observations are useful for estimating the soil moisture content. Passive microwave satellites have an advantage of direct sensitivity on surface soil moisture. However, their coarse spatial resolutions (10-36 km) are not suitable for regional-scale hydrological applications. Meanwhile, in-situ ground observations of point-based soil moisture content have the disadvantage of spatially discontinuous information. This paper presents an experimental soil moisture retrieval using Sentinel-1 SAR (Synthetic Aperture Radar) with 10m spatial resolution for cropland in South Korea. We developed a soil moisture retrieval algorithm based on the technique of linear regression and SVR (support vector regression) using the ground observations at five in-situ sites and Sentinel-1 SAR data from April to October in 2015-2017 period. Our results showed the polarization dependency on the different soil sensitivities at backscattered signals, but no polarization dependence on the accuracies. No particular seasonal characteristics of the soil moisture retrieval imply that soil moisture is generally more affected by hydro-meteorology and land surface characteristics than by phenological factors. At the narrower range of incidence angles, the relationship between the backscattered signal and soil moisture content was more distinct because the decreasing surface interference increased the retrieval accuracies under the condition of evenly distributed soil moisture (during the raining period or on the paddy field). We had an overall error estimate of RMSE (root mean square error) of approximately 6.5%. Our soil moisture retrieval algorithm will be improved if the effects of surface roughness, geomorphology, and soil properties would be considered in the future works.

Moisture Sorption Characteristics of Powdered Soybean Curd (분말(粉末) 두부의 수분흡착(水分吸着) 특성(特性))

  • Kim, Dong-Man;Chang, Kyu-Seob;Yoon, Han-Kyo
    • Korean Journal of Food Science and Technology
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    • v.12 no.4
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    • pp.292-298
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    • 1980
  • In order to improve the storage stability of powdered soybean curd, moisture sorption characteristics of the curd stored at specific relative humidity and temperature were investigated. The results obtained are summarized as follows; 1. When the fresh soybean curd (2cm thickness) was dried in a hot air drier at $55^{\circ}C$, it took 18 hrs to reduce its moisture content from 85% to 8.8%, and drying rate was very high during the first 5 hrs. 2. Equilibrum moisture content (E.M.C.) of powdered soybean curd by freeze drying was higher than that of sample by got air drying, but the particle size did not influence E. M. C. 3. The monolayer value of freeze dried powder of high E. M. C was higher than that of the hot air dried(8.30 vs 7.35). 4. The free energy for moisture absorption of freeze dried powder at 11% RH were 1285.1 cal/mole, 1323.5 cal/mole at $15^{\circ}C$ and $30^{\circ}C$, respectively, and the free energy of freeze dried product was lower that of hot air dried product. 5. The moisture sorption rate constant was not affected by particle size, and it showed that the moisture sorption rate decreased as temperature was increased. The rate constant of powder produced by freeze drying were 0.00804 at $15^{\circ}C$ and 0.00696 at $30^{\circ}C$.

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Equations for Water Sorption Isotherms of the Mixture of Dried Soymilk Residue and Wheat Flour (건조(乾燥)한 콩우유 비지와 밀가루 혼합물(混合物)의 등온흡습성질(等溫吸濕性質)과 관계식(關係式))

  • Sohn, Jung-Woo;Kim, Woo-Jung;Kim, Sang-Soon
    • Korean Journal of Food Science and Technology
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    • v.17 no.2
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    • pp.101-106
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    • 1985
  • Dried soymilk residue(SMR) which was prepared by washing with ethanol and acetone, followed by drying at $60^{\circ}C$ was investigated for its sorption characteristics and the relationship between moisture content and water activity when it was mixed with wheat flour. During storage at $20^{\circ}C$ and various RH, an excess sorption phenomena was observed for solvent treated and dried SMR before equilibrium reached. A simple equation of log(dw/dt)=b log t+log a, where t is storage time(hr) and w is %$(H_2O)$ was drived for sorption or desorption rate of dried SMR at RH range of 12%-92%. From sorption isothermifigure, the moisture content(Mi) could be calculated from water activity by the equation of Mi=b Aw+a. The proposed equation was proved to have better fitness than those of the Smith isotherm equation or Lang and Steinberg equation for the mixture of dried SMR and wheat flour.

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Water Absorption of Naked Barley Kernels Differing in Pearling Degrees (정맥 수율별 쌀보리의 수분흡수)

  • Park, Sung-Hee;Kim, Kwan;Kim, Sung-Kon
    • Korean Journal of Food Science and Technology
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    • v.21 no.5
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    • pp.601-605
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    • 1989
  • Water absorption of the major kernels(7 and 10mesh sizes) of naked barley differing in pearling degrees at $25-50^{\circ}C$ was investigated. The time to reach equilibrium moisture content was reduced by half upon removal of over 20% of the outer layer of the kernel. Water absorption rate and diffusion coefficient of naked barley of 5% pearling degree at $40^{\circ}C$ were faster about 1.5 and 2.8 times than those of unpearled one. The activation energy of hydration for unpearled naked barley was 11.5kcal/mole, which was decreased by approximately 0.4kcal/mole upon increasing the pearling degree by 5%.

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Factors Affecting Hydration Rate of Black Soybeans (검정콩의 흡수속도(吸水速度)에 미치는 영향인자)

  • Kim, Woo-Jung;Shin, Ea-Sook;Kim, Chong-Kun;Yang, Cha-Bum
    • Korean Journal of Food Science and Technology
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    • v.17 no.1
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    • pp.41-44
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    • 1985
  • Dried black soybeans were soaked in water at the temperature range of $4^{\circ}C-100^{\circ}C$ and in the solution having various concentration of salt and sugar, in order to investigate their effects on water absorption characteristics. The hydration rate was determined by the method of weight gain during soaking. The times required to reach specified degrees of hydration were reduced logarithmically by increase of temperature, with showing a break point in their Z-values at $60^{\circ}C$. The temperature effect on hydrations of black soybeans was higher at the temperature below $60^{\circ}C$. Increase of NaCl or sucrose concentration in soaking solution reduced the hydration rate. The Z-values were changed at the concentration of 25% for sucrose and 16% for NaCl. The activation energy for hydration of 30%-50% was found to be 5.7-7.2Kcal/mole. The higher activation energy was required to reach higher degree of hydration.

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Effect of Coating Materials on the Stability of Spray-Dried Lactobacillus Powder during Storage (코팅된 젖산세균 분말의 저장 안정성에 미치는 효과)

  • Kim, Soojin;Lee, SangYoon;Han, Jong-Kwon;Lee, Jae-Kwon;Choi, Mi-Jung
    • Korean Journal of Food Science and Technology
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    • v.47 no.5
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    • pp.633-638
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    • 2015
  • Lactobacillus is a probiotic that suppresses the growth of pathogens while preventing constipation, diarrhea, and intestinal inflammation. However, various environmental conditions such as pH and temperature affect the growth of Lactobacillus. In this study, Lactobacillus plantarum was encapsulated with starch using a spray dryer to protect the viability of the organism during storage and to increase its acid tolerance. The lower water activity and storage temperature resulting from this method influenced the survival of L. plantarum. In encapsulated Lactobacillus powders, viability of Lactobacillus was increased during storage at $20^{\circ}C$ relative to that of L. plantarum stored at $35^{\circ}C$ in the same water activity conditions. Furthermore, L. plantarum encapsulated in starch with ginger showed increased viability when compared to non-encapsulated L. plantarum stored without treatment. Finally, based on a simulated digestion test, encapsulated L. plantarum survived at a pH of 2, whereas the non-encapsulated L. plantarum did not. Thus, coating the encapsulated powder with these materials was effective in maintaining Lactobacillus viability.