• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.128-132
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• 1998

7S globulin has been isolate from the defatted soybean meal(glycine max,. merill) by Sepharose-6B column chromatography and CM-Sephadex column chromatography. Coagulum of 7S globulin formed at a temperature of $65^{\circ}C$ in microbial enzyme treatment. In order to characterize the structure of the coagulum, three kinds of coagulum (enzyme-, calcium-and acid-induced coagulum)were compared througth the Scanning Electron Microscope(SEM). The network structure was found to be of two levels. First, there was an appearance on the molecular level in the form of strands. Second, there was a denser network with a fine structure.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.77-82
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• 1997

The comparison soy protein coagulation by heat-and enzyme-treatment are summarized. The gelation mechanism of glycinin by heating was mainly due to dissociation and aggregation of the basic subunit of 11S globulin. In case of 7S globulin, macro-soluble aggregates may be formed by noncovalent intraction more than 30min at 8$0^{\circ}C$. Whereas, coagulum occured by the microbial enzyme was more minuter than the other Ca-, HCI-coagulum. Heat treatment attacked the basic subunit of 11S globulin and this results agreed very, how-ever, preferred acidic subunit to basic subunit of 11S globulin and attacked the 7S globulin, that could produce coagulum products within 4~5min at $65^{\circ}C$.

• Journal of Nutrition and Health
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• v.26 no.8
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• pp.998-1005
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• 1993

This study was attempted to investigate the effects of enzymatic modification of milk protein with Meju protease on its acid clotting and digestibility. The proteases used in this study were isolated from Meju(fermented soybeans) and had specific acticity of 250 units/mg protein at pH 7.0. These proteases were found to be at least 3 different isoenzymes of different pH optima(pH 4.0, 6.0, 10.0). The optimum temperature was 5$0^{\circ}C$. Hydrolyzed skim milk showed 30.5% degree of hydrolysis for 1 hr. and 36.4% degree of hydrolysis for 3.5 hrs. of protease treatment at pH 7.0. Upon acidification to pH 4.0, skim milk produced large and dense coagulum, but the coagulum was getting smaller by protease treatment. Generally, digestability of skim milk at pH 4.0 was lower than pH 2.0. At pH 4.0, native skim milk and control group had problem with hydrolysis of skim milk protein. Among protease treated groups, 1 hour treated skim milk was most effectively hyrolyzed at pH 4.0.

• Polymer(Korea)
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• v.27 no.6
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• pp.596-602
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• 2003

A Polymeric emulsifier was synthesized by solution polymerization with 2-ethylhexyl acrylate, n-butyl acrylate, and acrylic acid. A series of polymeric emulsifier have been used in the emulsion copolymerization of 2-ethylhexyl actryacrylate and n-butyl acrylate. The size of the synthesized latex particles was around 145 nm and its distribution was very narrow. Emulsion with polymeric emusifier showed no coagulum after 7 cycles of freeze-thaw test, while the emulsion with traditional emulsifier exhibited coagulum after 2 cycles. The adhesion tests showed that the initial tackiness and peel strength decreased as the molecular weight and acrylic acid content of polymeric emulsifier increased, whereas the holding power increased.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.199-204
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• 1983

As a way of utilizing cheese whey to fortify sulfur-bearing amino acids to soybean protein, whey-soybean coagulum was made from whey-soy milk mixture and optimum conditions for coprecipitation of the two proteins were determined. Mixture of whey and soymilk in 1 : 1 volume ratio was coagulated at $0.005{\sim}0.5M$ of $CaCl_2$ concentration, pH $1.5{\sim}8.0$, and at $60{\sim}100^{\circ}C$, and absorbance at 500nm of filtrate from the coagulum was measured. Optimum conditions for the coprecipitation were 0.0125M of $CaCl_2$ concentration, pH $6.5\sim7.5$, and $70{\sim}80^{\circ}C$ which resulted in the minimum absorbance and also good physical properties of the curd.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.69-75
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• 1992

Viscosity changes of acidified milk at the various pH $ranges(5.2{\sim}4.2)$was measured as a function of temperature. The rate and extent of acid-induced coagulation of milk protein were monitored by turbidity changes as a function of temperature, preheating and salt. Relative viscosities of acidified milk were also measured. The coagulation of casein occurred in a specific pH range and was accompanied by a sharp increase in viscosity at pH of $5.0{\sim}5.2$, depending on the heating temperatures. Onset pH of coagulation and maximum coagulation rate were enhanced by increasing temperatures and preheating process and reduced by addition of salt. Relative viscosity of acidified milk was reversed at the same conditions, reflecting the size of casein coagulum formed was related to the coagulation rate.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.447-450
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• 2000

Microorganism, including some bacteria isolated from soil, were found to secrete an extracellular soymilk-clotting enzyme. Using this bacterial enzyme experiments were carried out to optimize the hydrolyzing conditions for the production of soy peptides. The soy peptides produced by hydrolyzing 11S globulin with enzyme treatment at $65^{\circ}C$, pH 6.1, for 1hr were found to have a accessible possibility. The obtained coagulum by enzymatic reaction was very flocculation with fine structural formation. Properties of peptide Y and W of the enzyme hydrolysates at pH 6.1 were superior to that of isoelectric precipitation because these peptides were miscible with water in all proportions.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.305-305
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• 2009

The carbon nano-structured materials could be applied to the fields of advanced fillers, templates, electrode materials, sensor, storage, and absorption materials. The polyacrylonitrile (PAN) based carbon nano-particles provide the remarkable properties of high specific surface area, large pore volume, chemical inertness, and good mechanical stability. In this study, well-defined carbon nano-particles were obtained through pyrolysis of polyacrylonitrile based particles. The precursor nano-particles were prepared by modified aqueous dispersion polymerization using hydrophilic poly(vinyl alcohol) in a water/ N,N-dimethylformamide mixture media. Synthesized precursor nanoparticles have relatively monodisperse particles ranging 80 ~ 250nm. Stable spherical particles are obtained without coagulum or secondary particles in our system. The characteristic of the carbon nanoparticles were investigated in terms of surface area, morphology, and size distribution.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.279-284
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• 1984

Microstructure of milk powder and cheese made from milk powder were observed by electron microscope. Freeze dried milk powder showed apple-like appearance. The cheese made from freeze dried milk powder had relatively flat surface and homogenous deposit in compare with classical processed cheese. Imported milk powder also indicated similar surface as well as freeze dried milk powder, however, the cheese made from imported milk powder had somewhat coarse surface structures with the spaces between casein matrix and deposit. Commericial milk powder showed irregular shape in size and coagulum which were possibly denatured in the course of drying. The cheese made from commercial powder indicted irregular and small deposit and porous structure. The porousity of the cheese seemed to be influenced by the degree of heat treatment. Denatured protein would be less dispersive than native in presence of polyphosphates. Fat globule and protein micelle of cheese made from skim milk powder get very adjacent to each other and showed compactness of micelles. It is thought that melting mechanism of skim milk powder was different from the melting of typical processed cheese.

• Clean Technology
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• v.11 no.1
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• pp.41-50
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• 2005

In this study, semibatch emulsion copolymerization of n-BA as adhesive component and MMA as coagulant component were carried out for the stable acrylic polymer latex in aqueous phase for polymer cement using LE-type nonionic surfactant as environmental friendly surfactant. The stable polymer emulsion was obtained with the increases of chain length(n) of this surfactant. The effect on the amount of LE-50 as nonionic surfactant were showed that the concentration of polymer latex were increased by increasing the amount of LE-50, whereas the average particle size were decreased by increasing the amount. The addition of functional monomer in initial reactor charge showed a significant effect on the final polymer concentration and the latex particle size. The single polymerization of each n-BA or MMA showed a very low concentration of polymer latex and very big particle size due to coagulation. In the polymerization composed of mixed monomer with MMA and n-BA, the larger the ratio of MMA to n-BA in the copolymers, the greater the amount of coagulum produced. It was found that a stable copolymers were obtained in the range of 15-35 % of n-BA. Moreover, incorporation of some functional monomers in addition to of main monomers became more stable polymer latex. Through DSC and IR analysis, the final polymer latex was composed by MMA/n-BA/AA/AM with a single Tg depending on the reaction conditions. As a result, the conditions of this acrylic polymerization could also be effectively controlled to get the desired final products.