• Journal of Radiation Industry
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• v.5 no.4
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• pp.377-382
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• 2011

Poly(vinyl alcohol) (PVA) is an interesting material with good biocompatibility, high elasticity and hydrophilic chacrateristics. In this study, crosslinked hydrogels based on PVA, and poly(acrylic acid) (PAAc) were prepared by gamma-ray irradiation. PVA and PAAc powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make hydrogels. The hydrogels were then annealed in an oven at $120^{\circ}C$ for 10 min, 30 min and 50 min under nitrogen atmosphere. The properties of a hydrogel such as gel fraction, swelling behavior, thermogravimetric analysis (TGA) and adhesive strength as a function of PAAc content and annealing time were investigated. The gel fraction decreases with decreasing PAAc content and increasing annealing time. The thermal behaviors have shown different patterns according to the annealing time. The adhesive strength increases with increasing PAAc content.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1262-1267
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• 1999

Optimum reaction conditions for gel formation of rapeseed, Brassica napus, protein catalyzed by microbial TGase(transglutaminase) were evaluated by measuring breaking strength and deformation of gel. The polymerization of the protein gel was ascertained by SDS-PAGE and content of GL crosslinking$[{\varepsilon}-({\gamma}-glutamyl)lysine]$. In the reaction between rapeseed protein and TGase at $45^{\circ}C$ for 60 min, the breaking strength and deformation of the gel was the maximum at the ratio of 1 : 40 of enzyme to substrate. 10%(w/v) of rapeseed protein concentrate was optimum for gel production. The maximum breaking strength and deformation was shown at $45^{\circ}C$ The breaking strength increased linearly up to 90 min of the reaction time and remained unchanged. The breaking strength and deformation by TGase treatment was pH dependent and pH 7 was optimum for 10% rapeseed protein solution. SDS-PAGE analysis indicated that new band of highmolecular polymers were formed by the enzyme reaction, with disappearing the original bands of rapeseed protein. According to HPLC analysis. the content of GL crosslinking was increased from 0 to $7.14\;{\mu}mol/g$ gel for 90 min of the reaction time.

• Korean journal of food and cookery science
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• v.7 no.4
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• pp.63-69
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• 1991

This study was undertaken for the purpose of studying the physicochemical propery of mungbean and texture of mungbean starch gels. Mungbean starch gel made with different levels of oil were tested to investigate the textural characteristics by mechanical test. The results are summerized as fallows: The content of moisture fat, protein, and ash in Seonwha mungbean were shown to be about 13.19%, 1.02%, 23.57% 3.13% respectively. Those of Seonwha mungbean crude starch were 12.48%, 0.63%, 0.94%, 0.13% respectively. The gain of dry crude starch from peeled mungbean was 22.48%. Water binding capacity of Seonwha mungbean crude starch was 183.1%. The pattern of change in swelling power of Seonwha mungbean crude starch for increasing temperature increased slowly to $70^{\circ}C$, and then increased rapidly. The pattern of change in solubility was similar to that of swelling power. The amylose and amylopectin content were 22.5%, 77.5%. Brabender hot-paste viscosities of mungbean crude starch at 8% and 10% showed the similar amylogram patterns with peak vicosity. By the Rheometer measurement result of 8% 10% mungbean starch gel, Hardness and Fractuability tended to be decreased as the addition level of oil increased. Elasticity, Adhesiveness, Chewiness, L, a, and b value tended to be increased as the addition level of oil increased.

• Food Science and Preservation
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• v.20 no.3
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• pp.372-378
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• 2013

The objective of this study was to evaluate the quality characteristics of mungbean starch gels that were prepared with different concentrations (0, 0.5, 1.0 and 1.5%) of peach seed powders (PSP), which exhibit antioxidant characteristics. Mungbean starch gel samples were prepared and subjected to quality characteristics such as moisture content, general components, color, texture profile analysis, total polyphenol contents, DPPH radical scavenging activity, and sensory qualities. The L-value and the a-value for color decreased significantly, whereas the b-value increased significantly as the PSP concentration increased (p<0.05). In the texture profile analysis, the mungbean starch gel with 1.5% PSP showed significantly lower degrees of hardness, cohesiveness, springiness, gumminess and brittleness (p<0.05). The total polyphenol content was highest in the 1.5% PSP to which mungbean starch gel was added, which also showed a higher than 70% DPPH radical scavenging activity level in a dose-dependent manner (p<0.05). In the sensory test of the mungbean starch gel, its sensory scores for flavor and taste were highest in the 0.5% PSP to which mungbean starch gel was added.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.633-641
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• 1991

Mook, a traditional gel food in Korea, has been made from mainly acorn, buckwheat, and mungbean starches (Mook Starches). Corn, rice, wheat starches (Non-Mook Starches) are not used due to their weak gelation power. In order to know the effects of properties of starch on gelation, some physicochemical properties, molecular structure, and starch lipid of these six starches were investigated and compared with gel hardness. Both amylose content and gel hardness of starches were in order of mungbean, acorn, buckwheat, wheat, corn, and rice and these two parameters showed a very good correlation (r=0.95). The amyloses of Mook Starches had larger molecular size (${\overline}D.P._{n}=1,080{\sim}1,580\;vs\;670{\sim}1,120$ for Mook Starches and Non-Mook Starches, respectively), more average number of chain ($2.9{\sim}5.4\;vs\;1.7{\sim}2.5$), and shorter average chain length ($290{\sim}390\;vs\;390{\sim}450$) than those of Non-Mook Starches. Also, Mook Starches had longer average chain length ($22.2{\sim}22.6\;vs\;18.9{\sim}21.3$) of amylopectin and less starch lipid content ($0.12{\sim}0.49\;vs\;0.68{\sim}1.26%$) than Non-Mook Starches. These properties had good correlations with gel hardness (r=0.76-0.84). Consequently, the gelation power of Mook Starches was thought to be derived from their high amylose content and other properties of starches.

• Bulletin of the Korean Chemical Society
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• v.2 no.2
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• pp.60-66
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• 1981

The hypothesis that three classes of water exist in hydrogels, namely X water (free water-like), Z-water (bound water-like), and Y water (interfacial water-like), has been verified and generally accepted. To further check the validity of this hypothesis and to study the nature of X, Y, and Z water as conformation changes, several experiments have been done using Tactic Poly(2-hydroxyethyl methacrylate) (P-HEMA) gels. Thermal expansively data for tactic P-HEMA gel was obtained. In each case of isotactic and syndiotactic P-HEMA, the higher water content gels showed an extremely sharp volume change at $0^{\circ}C$, indicating the presence of normal free water-like. Lower water content gels showed no anomalous change in thermal expansion, indicating that the water is bound water-like. The medium water content gels exhibited intermediate behavior. These results were also confirmed by bulk gel conductivity measurments. The differential scanning calorimeter(DSC) experiment was simply introduced to further verify the bound water-like quantities which was obtained by the method of dilatometry and specific conductivity. Observing the amounts of X, Y, and Z water with the change of tacticity, the similar content of bound water-like may be due to the same primary structure of isotactic and syndiotactic polymer and the difference in free and interfacial water-like content may be due to the difference in secondary and tertiary structure of tactic polymer. Therefore, as the polymer conformation varies, the free and interfacial water-like content will be varied. In order to demonstrate these concepts, Russel et al.'s CPK space-filling molecular models of isotactic and syndiotactic P-HEMA was utilized.

• Journal of the Korean Ceramic Society
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• v.29 no.11
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• pp.870-876
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• 1992

Lead lanthanum zirconate titanate (PLZT, 6/65/35) powders, crack-free and dense thin films have been prepared by polymeric sol-gel process. Pyrolysis of the gel, crystallization and optical transmittance behavior of the PLZT thin film onto sapphire substrate have been studied. Esterification occurs during synthesis of PLZT complexation. Crystalline Pb phase was transiently formed near 450$^{\circ}C$. Content of perovskite phase in the films were increased with increasing thickness of film, but the kinetics of formation of perovskite phase in films was slower than that of powders. Transmittance of the films was decreased with increasing the temperature of heat treatment. Ferroelectric hysteresis loop measurements indicated increments of remanent polarization and coercive field for plenty more of perovskite phase.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.413-419
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• 1992

Deoxynivalenol producing isolates of Fusarium Graminearum R 6576 was grown on rice for 25 days at 19,25 and $28^{\circ}C$. Maximum production of deoxynivalenol(DON) by Fusarium graminearum R 6575 occurred at $28^{\circ}C$ and 20 days. Maximum concentration of 940 ppm DON were obtained after 20 days at an initial moisture content of 40%. A DON derivative, 15-acetyl-DON (15-ADON), was also found at concentrations of 150~300ppm after 5~10 days. Crude culture extracts were purified by water-saturated silica gel column chromatography which selectivity extracted DON when methylene chloride was as the mobile phase. Purity of crystallized DON was verified by thin layer and high performance liquid chromatography. Also this method was advantage method or production of DON and require little organic sorbent than the other methods.

• The Korean Journal of Ceramics
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• v.1 no.3
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• pp.160-164
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• 1995

Mechanical and chemical tests were performed on $Zro_2 \cdot SiO_2$ glass fibers manufactured by the sol-gel method and E-glass fibers-reinforced cement composites in order to investigate the interactions between glass fibers and cement matrices. Chemical attack leads to corrosion of the glass fiber surfaces. In the corrosion reactions, the surface of $30ZrO_2 \cdot 70 SiO_2$ glass fibers developed a densified concentric layer, which consists of glass corrosion products with much higher Zr and lower Si than the fresh glass fiber. The layer of reaction product is regarded to stiffen the cement matrices and provide a useful improvement to the mechanical properties. The addition of $ZrO_2$ content increases the corrosion resistance of glass fibers in cement by forming a passivating layer on the surface of glass fibers.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1181-1184
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• 2008

$GeO_2$/ormosil organic-inorganic hybrid films doped with neodymium ions and $TiO_2$/Ormosil organic-inorganic hybrid films dispersed with neodymium oxide nanocrystals are prepared by combining an inverse microemulsion technique and a low-temperature sol-gel technique. The effects of $Nd^{3+}$ concentration, $Nd_2O_3$ nanocrystal content, and heat treatment temperature on up-conversion and photoluminescence luminescence properties of the hybrid films are studied.