• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.737-744
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• 2001

This study was carried to investigate the changes in physical and chemical properties during preparation of Yukwa. Protein content of glutinous rice was decreased during soaking time and acid and pH values were increased while contents of lipid and ash were not changed. Particle size distribution showed thate average particle size of 7 days soaking treatment smaller than those of 3 days and starch damage of glutinous rice flour was increased during soaking time. The major flavor components after soaking were found ethyl ester acetic acid, ethanol, 2-butan -ol, 2-methyl 1-propanol, 1-butanol, 3-methyl 1-butanol and 1-pentanol, propanoic acid. Content of acetic acid and butanoic acid were rapidly increased during soaking time. Results for ratio of storage modulus(G') and loss modulus(G') in glutinous rice flour dough indicated $tan{\delta}$ was increased for a while and decreased as frequency increased. G' value was very similar with G' value after steaming which means rubber-like property while G' and G' value were changed after during storage time. Treatment at $-20^{\circ}C$ had the highest hardness for cutting degree of dough. There was no difference in color value between different water contents. Hardness of Bandegi (sheet) was decreased as water content increased and the highest popping value was obtained at 18% of water contents. Adding 3% soaked bean had higher redness value of Yukwa and lower value in yellowness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.827-832
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• 1998

Soybeans(Hwangkeum Kong) were stored at 5$^{\circ}C$, $25^{\circ}C$ and 35$^{\circ}C$ for 8 months to investigate the changes of the physicochemical properties. Less physicochemical changes were detected in the soybeans stored at 5$^{\circ}C$ than those stored at $25^{\circ}C$ and 35$^{\circ}C$. High temperature and long term storage caused a decrease in the nitrogen solubility index, whereas increases in acid value and organic acid content were detected. As the storage period was extended at high temperatues, the content of unsaturated fatty acids decreased, but the content of saturated fatty acids increased. Decoloration of soybeans was clearly recognized under high temperatures. The water soluble compoents such as total solids, nitrogen and reducing sugar during water-soaking at 2$0^{\circ}C$ for 16hrs were appreciably eluted from the soybeans stored for 8 months at high temperatures. The pH of the water extract slightly shifted to the acidic range.

• Journal of the Korean Wood Science and Technology
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• v.39 no.2
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• pp.156-162
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• 2011

To evaluate the bonding performance of reinforced glulam, the textile type of glass fiber and aramid fiber, and the sheet type of glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP) were used as reinforcements. The reinforced glulam was manufactured by inserting reinforcement between the outmost and middle lamination of 5ply glulam. The types of adhesives used in this study were polyvinyl acetate resins (MPU500H, and MPU600H), polyurethane resin and resorcinol resin. The block shear strengths of the textile type in glass fiber reinforced glulam using MPU500H and resorcinol resin were higher than 7.1 N/$mm^2$, and these glulams passed the wood failure requirement of Korean standards (KS). In case of the sheet types, GFRP reinforced glulams using MPU500H, polyurethane resin and resorcinol resin, and CFRP reinforced glulams using MPU500H and polyurethane resin passed the requirement of KS. The textile type of glass fiber reinforced glulam using resorcinol resin after water and boiling water soaking passed the delamination requirement of KS. The only GFRP reinforced glulam using MPU500H after water soaking passed the delamination requirement of KS. We conclude that the bonding properties of adhesive according to reinforcements are one of the prime factors to determine the bonding performance of the reinforced glulam.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1638-1644
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• 2001

The objective of this research was to evaluate alternative treatments for the best extraction condition for collagen from chicken feet. Various properties such as chemical composition, amino acid, pH, swelling percentage, yield and pure collagen, collagen loss, color (Hunter L, a and b) and electrophoresis of collagen from chicken feet treated by 5% acids (acetic acid, citric acid. hydrochloric acid and lactic acid) and soaking times (12, 24, 36 and 48 h) were evaluated. The crude protein, fat, ash and moisture contents of chicken feet was 17.42, 12.04, 5.98 and 62.05%, respectively. Amino acid composition of collagen from chicken feet indicated that the protein of collagen was markedly hydrolized by the hydrochloric acid treatment. The result of electrophoresis also supported this phenomenon. Both the swelling percentage of lactic acid and citric acid treatments were significantly higher than that of acetic acid and HC1 treatment. The pH of the acid treatments ranged from 2.43-3.62. According to the result of yield, pure collagen and loss of collagen, the best condition of extracting collagen from chicken feet was soaked in 5% lactic acid for 36 h. However, a brighter yellow color of collagen from all treatments was observed with a longer soaking time.

• Journal of the Korean Ceramic Society
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• v.44 no.4 s.299
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• pp.208-213
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• 2007

Alumina/silver ($Al_2O_3/Ag$) nanocomposites with Ag content up to 9 vol% were prepared from nanopowder by soaking method using ${\gamma}-Al_2O_3$ of needle type and spark plasma sintering (SPS). The mechanical properties of specimens were investigated three-point flexural strength and toughness as a function of the Ag contents. The maximum flexural strength of the alumina/silver nanocomposite was 850 MPa for the 1 vol% composite, and also higher than monolith alumina as about 800 MPa at 3, 5, and 7 vol% Ag contents. Fracture toughness by single edged V-notch beam (SEVNB) was $4.05MPa{\cdot}m^{1/2}$ for the 3 vol% composite and maintained about $4.00MPa{\cdot}m^{1/2}$ at 5, and 7 vol% Ag content. Microstructure of fracture surface for each fracture specimens was observed. Due to the inhibition effect of alumina grain growth, the average grain size of nanocomposites depends on the content of Ag nano particles. The fracture morphology of nanocomposite with dislocation (sub-grain boundary) by silver nano-particles of second phases in the alumina matrix also showed transgranular fracture-mode compare with intergranular of monolith alumina. Thermal conductivity of specimens at room temperature was about 40 W/mK for the 1 vol% Ag content.

• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.343-348
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• 2007

Alumina/silver nanocomposites were fabricated using a soaking method through a sol-gel route to construct an intra-type nanostructure. The pulse electric-current sintering (PECS) technique was used to sinter the nanocomposites. Several specimens were annealed after sintering. The microstructure, mechanical properties, critical frontal process zone (FPZ) size, and thermo-mechanical properties of the nanocomposites were estimated. The relative densities of the specimens sintered at 1350 and $1450^{\circ}C$ were 95% and 99%, respectively. The maximum value of the three-point bending strength was found to be 780 MPa for the $2{\times}2{\times}10 mm$ specimen sintered at $1350^{\circ}C$. The fracture toughness of the specimen sintered at $1350^{\circ}C$ was measured to be $3.60 MPa{\cdot}m^{1/2}$ using the single-edge V-notched beam (SEVNB) technique. The fracture mode of the nanocomposites was transgranular, in contrast to the intergranular mode of monolithic alumina. The fracture morphology suggested that dislocations were generated around the silver nanoparticles dispersed within the alumina matrix. The specimens sintered at $1350^{\circ}C$ were annealed at $800^{\circ}C$ for 5 min, following which the maximum fracture strength became 810 MPa and the fracture toughness improved to $4.21 MPam^{1/2}$. The critical FPZ size was the largest for the specimen annealed at $800^{\circ}C$ for 5 min. Thermal conductivity of the alumina/silver nanocomposites sintered at $1350^{\circ}C$ was 38 W/mK at room temperature, which was higher than the value obtained with the law of mixture.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.425-430
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• 2002

Physicochemical properties of chicken feet gelatin produced under acidic and alkaline conditions were investigated. Amino acid content of chicken feet gelatin was different from that of commercial gelatin due to the differences in raw materials and production process. Yield and hardness of chicken feet gelatin reached maximum at 24 h under acidic condition and at 1 week under alkaline condition, respectively. As the soaking period increased, viscosity and clarity increased under acidic condition, while decreased under alkaline condition. Color of the acid-treated chicken feet gelatin gel was more desirable than that of the alkali-treated on based upon L, a, b values. From gel permeation chromatography of the chicken feet gelatin, 12 subunits were detected. The amount of high molecular weight subunits, which is related to viscosity and hardness, of the alkali-treated chicken feet gelatin was twice as much as that of the acid-treated one.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.45-49
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• 2010

To reduce the astringent taste of lotus root, the effects of various treatment methods such as drying, soaking, steaming and roasting on the physicochemical properties and sensory characteristics were investigated. The following process conditions were selected: 1) drying (D), 2) soaking followed by drying ($SK{\rightarrow}D$), 3) steaming followed by drying ($ST{\rightarrow}D$), 4) drying followed by roasting ($D{\rightarrow}R$), 5) soaking and then drying followed by roasting ($SK{\rightarrow}D{\rightarrow}R$), 6) steaming and then drying followed by roasting ($ST{\rightarrow}D{\rightarrow$}. The tannin content of the lotus root was lowest when it was treated by steaming followed by drying ($ST{\rightarrow}D$). The astringent taste of lotus root was reduced by steaming, and the roasted taste was improved by roasting in terms of sensory and flavor characteristics. Consequently, lotus root treated by steaming and then drying followed by roasting ($ST{\rightarrow}D{\rightarrow}R$) showed the highest preference with respect to astringent and roasted taste.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.272-277
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• 1990

Some additives were applied to improve Yukwa(Popped rice snack) quality and process modifications were tested for cutting down soaking time and application of rice flour. Addition of soaked soybean (3%, w/w) to dough showed higher expansion rate and better physical properties with more acceptable quality by sensory evaluation of Yukwa. Baking powder, modified starch and alcoholic liquor, Mackeali(rice wine, turbid). Soju(distilled liquor) and Yakju(rice wine, clear), were no positive effect on quality of Yukwa but alcoholic liquor gave more fine texture than others. High temprature soaking $(60^{\circ}C)$ of rice for 3 hours which is near gelatinization temperature of rice starch. gave same quality of Yukwa comparing with long time soaking (12 hours) at room temperature. Extention of high temperature soaking (12 hours) did not improve the quality of Yukwa. The 100 mesh of rice flour by dry milling method was better in expansion rate and hardness than 40 and 80mesh but it was worse than ordinary wet milling. It was notified that milling method and milling mechines for Yukwa preparation should be studied in more detail.

• Food Science and Preservation
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• v.13 no.6
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• pp.686-690
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• 2006

Quality properties of legumes (Seoritae and red bean) with soaking of 3% NaCl solution and microwave dying were evaluated. The samples were soaking with 3% NaCl at $25^{\circ}C$ for 6 hr(Seoritae) and 12 hr(red bean). Moisture content of Seoritae and red bean after soaking are 35.8%, and 35.1% respectively. The samples were dried with microwave treatment and cooling with microwave treatment combination secondly to $12{\sim}14%$ for moisture content Hardness of Seoritae was decreased from $12,863g_f$ to $3,309g_f$. There was a difference between varieties on color value. Hardness of cooked rice with ratio of milled rice and legumes(7:3) was $3,165g_f$ which is lower value compared to regular cooked mixed rice. Sensory evaluation of cooked mixed rice showed that treated samples have higher scores on color, flavor, taste, texture and overall acceptability values than those of control.