• Bulletin of the Korean Chemical Society
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• v.4 no.4
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• pp.162-169
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• 1983

The swelling and stress-elongation experiments have been performed for two kinds of gels of tactic poly (2-hydroxyethyl methacrylate) (P-HEMA) with varying crosslinker concentrations. The gels of isotactic and syndiotactic P-HEMA were swollen in aqueous salt solutions upon varying molal concentrations. The solute used were NaCl, $MgCl_2$, $Na_2SO_4$, $MgSO_4$ and urea. The water content at equilibrium swelling and the salt partition coefficient were determined, and stress-elongation curves of the gels were obtained. From these results, the effective number of chain (${\nu}_e$) and the Flory-Huggins interaction parameter (${\chi}_1$) were also obtained. The swelling experiment was also performed under varying solvents, and the degree of swelling was determined. The solubility parameter of P-HEMA was obtained as 13.4 (cal/mole)$^{l/2}$ using the correlation between the degree of swelling and the solubility parameter (${\delta}_1$) of solvents. The mechanical properties of syndiotactic P-HEMA is stronger than that of isotactic P-HEMA, and the water content of both gels become smaller when the crosslinking increases. Isotactic P-HEMA contains more water content than syndiotactic P-HEMA does.

• Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.31-39
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• 2022

To clarify the factors influencing the physical properties of fish after heat treatments, we investigated changes in the properties of proteins in the dorsal ordinary and dark muscle of yellowtail (Seriola quinqueradiata) heated under different conditions commonly used for the purposes of food hygiene. High-temperature/short-time heating (85℃ for 90 s and 75℃ for 60 s) affected the protein solubility more than low-temperature/long-time heating (63℃ for 30 min). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and differential scanning calorimetry showed that low-temperature/long-time heating reduced the degree of actin denaturation in fish compared with that by other heating conditions. In addition, collagen solubility was enhanced with low-temperature/long-time heating. Therefore, these results suggest that differences in the degree of actin and collagen denaturation are responsible for the enhanced meat tenderness and diminished meat shrinkage, resulting from low-temperature/long-time heating.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.20-25
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• 1996

Wood chips of oak(Quercus mongolica) and larch(Larix leptolepis) were exploded with the optimum condition. Main components of exploded wood were separated with hot hot water and methanol. The hemicelluloses were purified from hot water extracts and alditol complexs were prepared from purified hemicellulose. And also, cellulose nitrate was prepared from extractive residue and characterized. The results can be summarized as follows. 1. Amounts of carbohydrate(72~79%) in the crude hemicellulose of larch wood was more than those of oak wood(55~66%). 2. The crude hemicelluloses were mainly composed of oligosaccharides in oak wood but those in larch wood contained about 50% monosaccharides. 3. Decolorization of hemicellulose was successful with activated charcoal and ion-exchange resin treatment. The alditol yields were 56.3~82.9%. 4. The degree of substitution(D.S.) of cellulose nitrate was 1.95~2.87 and it showed a good acetone solubility.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.152-157
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• 2000

In order to select the optimum drying method for the production of cinnamon extract, water extract and 70% ethanol extract of cinnamon were prepared. And then several drying method of oven drying, vacuum evaporation, spray drying and freeze drying were performed. Content of cinnamic acid, cinnamic aldehyde, eugenol, tannin and free sugar, and antioxidant activity, degree of browning, pH, color value, turbity and solubility were compared. In water extract, contents of cinnamic acid, cinnamic aldehyde, eugenol were 29.45mg/100g, 94.86mg/100g, 120.75mg/100g and decreased to 4.76%∼44.21%, 5.30%∼48.05%, 3.66%∼21.83% by oven dyring, vaccum drying, spray drying respectively, but freeze drying showed a little decrease of those components. In 70% ethanol extract, effectual components decreased to 76.05%∼88.38% and 26.86%∼78.76% by freeze drying and vacuum evaporation respectively. Antioxidant activity decreased by drying and decreasing rate in 70% ethanol extract was lower than water extract. Degree of browning increased as the drying temperature increased. Tannin and free sugars were little affected by drying temperature. Solubility decreased in oven drying and 70% ethanol extract. Overall data suggested that optimum drying methods of cinnamon extract were freeze drying in case of water extract and freeze drying and vaccum drying in case of 70% ethanol extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.587-594
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• 2010

To develop commercially available food protein hydrolysates, the effects of different types of enzymes and substrates on bitterness and solubility of partially hydrolyzed food proteins were investigated. Four types of proteins (casein, isolated soy protein (ISP), wheat gluten, and gelatin) and five types of proteolytic enzymes (a microbial alkaline protease (alcalase), a microbial neutral protease (neutrase), papain, bromelain, trypsin) were used. To profile the pattern of hydrolysis, the degree of hydrolysis (DH) were monitored during 180 min of reaction time by pH-stat method. Casein showed the highest susceptibility to hydrolysis for all five proteases compared to those of ISP, gluten, and gelatin. In addition, the bitter intensity and solubility (nitrogen soluble index, NSI) of each protein hydrolysate were compared at DH 10%. Bitterness and solubility of protein hydrolysates were highly affected by DH and the types of enzymes and substrates. At DH=10%, casein hydrolysate by trypsin, ISP and gluten hydrolysates by either bromelain or neutrase, and gelatin hydrolysates by the five proteases tested in this study were highly soluble and less bitter.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.116-116
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• 1997

Complex formation of practically insoluble dexamethasone dipropionate (DDP) with ${\beta}$-cyclodextrin (${\beta}$-CD), dimethyl-${\beta}$-cyclodextrin (DMCD), trimethyl-${\beta}$-cyclodextrin (TMCD), 2-hydroxypropyl-${\beta}$-cyclodextrin (HPCD) and sulfobutyl ether ${\beta}$-cyclodextrin (SBCD) in water was investigated by solubility method at various temperatures. Water solubility of DDP was found to be 1.78 $\mu\textrm{g}$/$m\ell$ at 37$^{\circ}C$. Propylene glycol (PG)-water cosolvent increased the solubility of DDP, but the solubilization was not sufficient (8.93 $\mu\textrm{g}$/$m\ell$ in 20% PG). The addition of CD markedly increased the solubility of DDP in water, and A$\sub$L/ type phase solubility diagrams were obtained with ${\beta}$-CD, TMCD, HPCD and SBCD, where the apparent stability constants of the soluble complexes at 25$^{\circ}C$ were determined to be 1388, 216, 1054, and 1992 M$\^$-1/, respectively. However, DMCD remarkably increased the solubility of DDP, and showed an A$\sub$P/ type diagram, suggesting that DMCD forms a soluble complex of high order with DDP. The stability constant for the DDP-DMCD complex at 25$^{\circ}C$ was determined to be 19132 M$\^$-1/. The thermodynamic parameters were calculated for the inclusion complex formation in aqueous solution. CD (1${\times}$10$\^$-2/M) remarkably decreased the partition coefficients of DDP between isopropyl myristate/water in the order of TMCD < ${\beta}$-CD < HPCD < SBCD < DMCD, and in squalane/water system in the order of HPCD < TMCD < ${\beta}$-CD < DMCD < DMCD $\leq$ SBCD. This finding represents that, in a o/w type cream, cyclodextrin complexation with DDP may result in high concentration of DDP in aqueous phase. The permeation of DDP through a cellophane membrane was highly suppressed by the addition of CD, and the degree of suppression was different among CDs, indicating that CD may control the skin permeation of DDP. The dissolution rates of solid dispersions with CDs were much faster than those of drugs alone and corresponding physical mixtures. All DDP-CD solid dispersions exceeded the equilibrium solubility. Consequently these results suggest that complex formation of DDP with CDs may provide useful means to markedly enhance the solubility, and CDs are useful in the semi-solid preparations such as creams and gels for topical application.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.3
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• pp.87-96
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• 1994

This study was carried out to investigate the effect of hydrolysis by proteolytic enzymes on the functional properties of sesame protein concentrate. Sesame protein concentrate was hydrolyzed with papain, pepsin and trypsin to obtain 10% and 20% degree of hydrolysis. The nirogen solubility in water was increased with increasing the degree of hydrolysis. Bulk density was increased by enzymatic hydrolysis but water absorption capacity was increased only in the case of pepsin-hydrolyzed SPC. Higher fat absorption capacity was found in SPC with 10% DH than SPC with 20% DH. Emulsifying activity was also increased by enzymatic hydrolysis except SPC with 10% DH by papain.

• Korean Journal of Materials Research
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• v.21 no.12
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• pp.639-643
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• 2011

Zinc oxide as an optoelectronic device material was studied to utilize its wide band gap of 3.37 eV and high exciton biding energy of 60 meV. Using anti-site nitrogen to generate p-type zinc oxide has shown a deep acceptor level and low solubility. To increase the nitrogen solubility in zinc oxide, group 13 elements (aluminum, gallium, and indium) was co-added to nitrogen. The effect of aluminum on nitrogen solubility in a $3{\times}3{\times}2$ zinc oxide super cell containing 72 atoms was investigated using density functional theory with hybrid functionals of Heyd, Scuseria, and Ernzerhof (HSE). Aluminum and nitrogen were substituted for zinc and oxygen sites in the super cell, respectively. The band gap of the undoped super cell was calculated to be 3.36 eV from the density of states, and was in good agreement with the experimentally obtained value. Formation energies of a nitrogen molecule and nitric oxide in the zinc oxide super cell in zinc-rich conditions were lower than those in oxygen-rich conditions. When the number of nitrogen molecules near the aluminum increased from one to four in the super cell, their formation energies decreased to approach the valence band maximum to some degree. However, the acceptor level of nitrogen in zinc oxide with the co-incorporation of aluminum was still deep.

• Journal of Sericultural and Entomological Science
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• v.45 no.1
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• pp.46-57
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• 2003

This study was carried out to investigate the characteristics of the soluble sericins after degumming and after hydrolysis of insoluble sericin with various enzymes. Especially, the hydrolysis characteristics were examined in terms of molecular weight of the soluble sericin. Amino acid composition and molecular weight characteristics of the soluble sericins were also studied. When the insoluble sericin was hydrolyzed with kojizyme and flavourzyme, the solubility was highest at pH 7 and 50$^{\circ}C$. On the other hand, in the cases of protamex and alcalase, the highest solubility was obtained at 60$^{\circ}C$. In these cases, solubility increased with pH. In enzymatic hydrolysis, the solubility was increased with concentration of enzymes until 4 hours. After then, a slight difference was found along with treatment times. In enzymatic hydrolysis, the absorbance of the soluble sericin was increased with concentration of enzymes and treatment times. Average degree of polymerization was decreased with treatment time and concentration. The amino acid compositions were similar in low(low molecular weight by degumming) and high (high molecular weight by degumming). Those of PK (soluble sericin hydrolyzed with kojizyme), PP (soluble sericin hydrolyzed with protamex), and PA(soluble sericin hydrolyzed with alcalase) were similar to each other. Serine and tyrosine compositions were higher in low and high than those of PK, PP, and PA. However proline was absent in low and high. Molecular weights of the various sericins became higher as KP>high>PP>low>PA and those of KP and PA were 9,800 and 905 respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.607-611
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• 1999

Carrageenan are sulfated polymers containing galactose and anhydrogalctose units, and is used for its gelling, thickening, stabilizing, emulsifying, and suspending properties. However, carrageenan is limited to use beyond $0.03\%$ as food additives because of its high degree of gelling and viscosity with low solubility. The use of ultrasound significantly reduced the viscosity of $\lambda$-carrageenan solutions. The optimal parameters of ultrasound for reduction of carrageenan molecular weight were temperature, $10^{\circ}C$ ultrasound intensity, 114.7 $W/cm^2$ ; carrageenan concentration, $2\%$; treatment time, 10 min. The molecular weights of control, ultrasound peak 1, and peak 2 were approximately 250,000, 184,000, and 67,000 daltons, respectively. The lower molecular weight of $\lambda$-carrageenan showed the higher solubility, the lower alcohol precipitation ratio and the lower emulsifying capacity. Browning degree of both control and lower molecular $\lambda$-carrageenans was not significantly different.