• Title, Summary, Keyword: freeze treatment

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Molecular Analysis of Freeze-Tolerance Enhanced by Treatment of Trinexapac-Ethyl in Kentucky Bluegrass

  • Hwang, Cheol Ho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.2
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    • pp.176-179
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    • 1999
  • Trinexapac-ethyl[ 4-(cyclopropyl- $\alpha$ -hydroxy-methylene)-3,5-dioxocyclohexane carboxylic acid ethylester] is a growth-retardant for plants by inhibiting a key step in biosynthesis of GA. A treatment of trinexapacethyl generally induces a reduction in vegetative growth and also inhibits heading. In addition, the trinexapacethyl was known to enhance the freeze-tolerance in annual bluegrass, however, the mechanism is not known yet. One possible reason for the enhanced freeze-tolerance may be the antifreeze protein known to be accumulated in intercellular space of the leaf during cold acclimation. In order to see the possible in-duction of the synthesis of antifreeze proteins by trinexacpacethyl, the apoplastic proteins extracted from Kentucky bluegrass treated with trinexapacethyl were analyzed by SDS-PAGE and the presence of the antifreeze protein was observed. In addition, western analysis showed the identity of the protein induced by both a cold acclimation and a trinexapacethyl treatment. It appears that an enhanced freeze-tolerance of the turf grass by trinexapacethyl is due to the synthesis and/or accumulation of the antifreeze protein similar to the enhanced freeze tolerance induced by cold acclimation.

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Preparation of Freeze-dried Cefazolin Sodium Bulk Powder with Good Flowability (유동성이 우수한 분체특성을 갖는 세파졸린 나트륨 진공동결건조 분말의 제조)

  • Cho, Jeong-Sik;Jeong, Eun-Ju
    • YAKHAK HOEJI
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    • v.42 no.3
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    • pp.284-289
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    • 1998
  • The effect of reaction condition, solvent addition and thermal treatment on the bulk density, crystallinity and chemical properties of the freeze-dried cefazohn sodium was inves tigated to prepare the cefazolin sodium powder for injection with good flowability. Crystalline cefazolin sodium powder with high untapped-bulk density (about 45%) and low compressibility (about 40%) was obtained by solvent addition to the very highly concentrated cefazohn sodium solution followed by subsequent thermal treatment before freeze-drying. The desirable solvent was low substituted alcohol such as isopropyl alcohol and anhydrous ethanol with the final concentration of about 9%. The pH adjustment and nitrogen gas purging during the reaction did not give significant effect on the chemical properties such as content, color, transmittance and pH of the reconstituted cefazolin sodium aqueous solution.

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Comparison of Physicochemical and Sensory Properties of Freeze-concentrated Milk with Evaporated Milk during Storage

  • Hwang, J.H.;Lee, S.J.;Park, H.S.;Min, S.G.;Kwak, H.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.2
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    • pp.273-282
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    • 2007
  • This study was carried out to compare the changes of nutrients, sensory and chemical properties of freeze-concentrated and evaporated milks during storage. For pasteurization, the freeze-concentrated milk containing 27% of total solid was treated with 150 rpm ozone for 5 min, and 99% of microflora was eliminated. Also, the activities of protease and lipase decreased 93.31% and 96.15%, respectively, and phosphatase showed negative activity. Total bacteria count was maintained below$2.0{\times}10^4$CFU/ml. During storage, TBA absorbance was lower in freeze-concentrated milk than that in the evaporated milk. The production of short-chain free fatty acids and free amino acids increased proportionally to the storage period in both samples. While the short-chain free fatty acid production was lower in the freeze-concentrated milk compared with that in the evaporated milk, the production of individual free amino acid was similar in both samples. In sensory evaluation, cooked flavor and color were much lower in the freeze-concentrated milk than that in the evaporated milk. Overall acceptability score was higher in the freeze-concentrated than the evaporated milk. Based on above results, ozone treatment for the freeze-concentrated milk pasteurization was positive at the elimination of microflora and enzyme inactivation. During storage, the freeze-concentrated sample minimized the change of color and TBA absorbance, the production of short-chain free fatty acid and vitamins than the evaporated milk. Therefore, the freeze-concentrated milk process in the present study resulted in the positive effect in minimizing nutrient loss and keeping quality of milk during storage.

In Vitro Development of Porcine Oocytes Following Intracytoplasmic Injection of Freeze-Dried Spermatozoa with Trehalose (Trehalose에 의하여 동결 건조된 정자의 돼지 난자 내 직접주입 후 체외 배발달)

  • Kang, Hwa-Hyung;Lee, Ji-Woong;Kang, Man-Jong;Kim, Kwang-Hyun;Moon, Seung-Ju
    • Journal of Embryo Transfer
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    • v.29 no.1
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    • pp.51-57
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    • 2014
  • The objectives of this study were to investigate the effects of trehalose as a cryoprotectant for porcine freeze-dried spermatozoa, to find the optimal freeze-drying time and storage periods of freeze-dried spermatozoa, and to find out pronuclear formation rates, cleaved rates, and embryo development through intracytoplasmic injection of freeze-dried spermatozoa on porcine oocytes. The survival rates of spermatozoa after freeze-drying with trehalose treatment were significantly higher than those of them without trehalose treatment (p<0.05). The highest survival rates were found at 75 mM trehalose treatment. The longer storage periods after freeze-drying seemed to have a lower survival rates. Development in culture of pig by ICSI with trehalose treatment were significantly higher than those of them without trehalose treatment (p<0.05). Shorter freeze-drying time of spermatozoa was resulted in the highest cleaved rates and embryo development.

A Fixed Grid Finite Volume Analysis of Multi-Dimensional Freeze Drying Process under Vacuum Condition (고정격자계에서 유한체적법을 이용한 진공동결건조 과정의 열 및 물질전달에 대한 연구)

  • Chi-Sung, Song
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.981-992
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    • 2004
  • Freeze drying under vacuum condition is a complex process that involves simultaneous heat and mass transfer, sublimation of ice, and motion of sublimation front. Proper treatment of the motion of sublimation interface is crucial for an accurate prediction of the freeze drying process. Based on the enthalpy formulation that has been successfully used in liquid/solid phase change problems. a fixed grid method. streamlined for the freeze drying analysis. was developed in this study. The accuracy of the fixed grid method was checked by solving a one-dimensional tray freeze drying and a two-dimensional vial freeze drying problem and then comparing the results with those by the moving grid method. Finally. the freeze drying characteristics of two-dimensional slab and axis-symmetric cylinder was investigated using the fixed grid method.

A study for conservation of plant-based cultural properties : on the subject of straw sandals excavated at Goongnamji in Buyeo (초본류 문화재의 보존처리를 위한 연구 -부여 궁남지 출토 짚신을 대상으로-)

  • Na, Mi-Sun;Kim, Ik-Joo;Kim, Soo-Ki
    • 한국문화재보존과학회:학술대회논문집
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    • pp.115-130
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    • 2004
  • Plant-based cultural assets using straw and grass as household goods of our people's have been used as indispensable tools for practical living for a very long time. However, only a limited number of artifacts were unearthed so far due to tile fragility of the material. For this reason, research on plant-based cultural properties had close to no progress, and the appropriateness of the PEG method, high-grade alcohol method, alcohol--ether-resin method, and Paraloid B-72 used in preserving plant-based cultural properties has not been sufficiently investigated. Therefore, this study examined the weight change rate by applying the methods of Primal MC-76 and vacuum freeze-drying used mostly as a earth-layer hardening material among PEG and acrylic resin, which are applied widely for preservation of waterlogged archaeological wood, as a means to preserve plant-based cultural properties along with the examination of the subject material, and an experiment was also performed on moisture absorption. The findings as a result were, first, the plant-based material being studied was found to be Typha (Typha orientalis Presl). Secondly, the weight change experiment applying $PEG\#400$ and $PEG\#4000$ confirmed a steady increase of weight if PEG -2Step is used for treatment. Third, in preserving all subject materials with soil, treatment with $PEG\#4000$, Primal MC-76, and vacuum freeze-drying showed that tile vacuum freeze-drying method resulted in the largest or $20\%$ reduction in weight, while Primal MC-76 resulted in $18\%$ and $PEG\#4000$ in $8\%$ of weight reduction. It was concluded that, considering the stability of soil measurement, this came to be because resin permeation was carried out along with tile drying process. Fourth, the weight changes were found to be around $10\%$ in various humidity conditions after the preservation treatment. The greatest weight change rate was seen in the case of $PEG\#4000$, particularly having chemicals gush out in a high humidity (RH $84\%$ or higher) environment. In the case of Primal MC-76 and vacuum freeze-drying methods, $6\~8\%$ weight changes were detected, and the lowest weight change was found in the case of the vacuum freeze-drying method. Fifth, as for color changes after treatment, blackening occurred most strongly with $PEG\#4000$, while Primal MC-76 and vacuum freeze-drying manifested colors closest to dry straw or grass. However, the texture of straw was not very evident in the case of Primal MC-76, due to a glossy surface, but vacuum freeze-drying was found to offer tile best result in terms of texture. Putting together the results of the above experiments, vacuum freeze-drying presented after being treated with PEG2-Step the most stabilized changes in weight, while it offered the smallest change in color as well.

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A Study on the Infrared Emission Properties and Freeze-thaw Resistance for Calcined Clay by Carburization Treatment (소성 점토의 침탄에 따른 동결융해 저항성 및 적외선 방사특성 연구)

  • Kim, Ki-Ho;Kim, Sang-Myoung;Kang, Byung-Chul
    • Journal of the Korean Ceramic Society
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    • v.45 no.7
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    • pp.387-394
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    • 2008
  • The Physical property changes of calcined clay by carburization were investigated studied. The carburization mechanism is the penetration of carbon which occurred during incomplete fuel combustion into crevice of clay structure. The experiments for elasticity and freeze-thaw resistance were conducted, and the results can be summarized as follows: Dynamic modulus of elasticity and also freeze-thaw resistance of calcined clay by carburization treatment increased more than 92% after testing 300 cycle, which was more improved than 88% of calcined clay. Therefore, it can decrease the possibility of winter-sowing, which is one the weakness of calcined clay. It is on the basis of the fact that the porosity of calcined clay by carburization treatment is about 12%, which indicates smaller pore spaces comparing with the 14% of porosity of calcined clay and those values were calculated by apparent porosity show and also supported by SEM images. Infrared emissivity of calcined clay by carburization treatment and calcined clay were respectively 0.92 and 0.9l at $80^{\circ}C$. However, those values were 0.91 and 0.88 at $200^{\circ}C$, which means infrared emissivity of calcined clay by carburization treatment shows 3.6% higher than the calcined clay. Moreover, within the wavelength range from 3 to $7\;{\mu}m$, while the calcined clay had low infrared emissivity, the calcined clay by carburization treatment had increased infrared emissivity. It is inferred that it was affected by carbon element that has high infrared absorptivity within this wavelength range.

A study on energy efficiency improvement of waste-water treatment system by freeze concentration method (동결농축법을 이용한 폐수처리시스템의 에너지 효율 향상에 관한 연구)

  • Kim, Jung-Sik;Lim, Seung-Taek;Oh, Cheol
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.5
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    • pp.467-476
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    • 2013
  • Freeze concentration method has advantages of high thermodynamic efficiency, low energy consumption and purified water re-use. In this study, freeze concentration waste-water system which was designed as the small and medium sized capacity was analyzed about the rate of electric power consumption and the daily treatment capacity to suggest the direction of system development. At first, power consumption and operation time of the system with fresh water precooler or without it was calculated by computer modeling and analysis. Subsequently, the change of design treatment capacity was applied to the system with fresh water cooler. As a result, the rate of electric power consumption was higher as 0.6 Wh/kg but daily treatment capacity increased in quantity as 19 % in the system with fresh water precooler. As design treatment capacity increased, the rate of electric power consumption was lower and daily treatment capacity was larger in quantity.

Storage Stability of Freeze Dried Loach for Instant Choo-o-tang (즉석 추어탕을 냉동 건조미꾸라지의 저장성)

  • 류홍수;문숙임;이수정;문갑순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.153-160
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    • 1999
  • Storage stability of boiled and freeze dried loach and antioxidative effect of Zanthoxylum schinifolium were studied to confirm the possibility in development of instant choo o tang(Korean traditional loach soup). Packaging and storage temperature did not cause a measurable change in in vitro protein digestibility and trypsin indigestible substrate within 45 days of storage but remarkable quality changes were occurred in all samples stored after 60 days. Vacuum packaging and low temperature storage(4 oC) had some effect in retarding protein quality deterioration due to delaying polyunsaturated fatty acid oxidation. Maximum peroxide value and TBA value were reached in 15 days, and there were a slow(TBA value) and rapid reduction(POV) after peaks were reached. In contrast, increasing brown pigment development and fluorescence intensity continued until 90 days of storage. Treatment of ethanolic extracts from Zanthoxylum schinifolium prior to freeze drying could protect against lipid oxidation of freeze dried loach products.

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Effect of Ginseng Polysaccharide on the Stability of Lactic Acid Bacteria during Freeze-drying Process and Storage

  • Yang, Seung-Hyun;Seo, Sung-Hoon;Kim, Sang-Wook;Choi, Seung-Ki;Kim, Dong-Hyun
    • Archives of Pharmacal Research
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    • v.29 no.9
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    • pp.735-740
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    • 2006
  • Lactic acid bacteria (LAB) quickly attenuate or are killed during the freeze-drying process and storage. The effect of some natural polysaccharides, which are known as potent antitumor and immunomodulating substances, on the viability of the LAB, Lactobacillus acidophilus and Bifidobacterium breve, on freeze-drying and storage were investigated. Among the polysaccharides tested, red ginseng polysaccharide (RGP) and chitosan significantly inhibited the cell death of the LAB during freeze-drying, and fucoidan and RGP most potently protected the cell death of the LAB during storage. The stabilities of the LAB on the addition of RGP and fucoidan were comparable to that of skimmed milk. However, white ginseng polysaccharide (WGP) did not promote storage stability. When 5% skimmed milk/5% RGP treated LAB were freeze-dried and stored, their viabilities were found to be significantly higher those treated with 5% or 10% RGP. The stabilizing effect of 5% RGP/5% skimmed milk during LAB freeze-drying and storage stability was comparable to that of treatment with 10% skimmed milk. Based on these findings, we believe that RGP beneficially improves the stability of LAB during the freeze-dry process and storage.