• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.479-485
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• 2009

In this study, basic physical properties were measured for ASCO EQ85 cationic surfactant of triethanolamine-ester quaternary ammonium salt and effect of pH on softening performance on fabrics was investigated using zeta potential measurement and adsorption experiment by quartz crystal microbalance. The CMC of the surfactant was near $3{\times}10^{-3}mol/L$ and the surface tension at CMC was about 40 mN/m. The interfacial tension measurement between 1 wt% aqueous solution and n-dodecane measured by spinning drop tensiometer showed that interfacial tension slightly increased with an increase in pH but the equilibration time was not affected by pH. The surfactant adsorption was found to increase with an increase in surfactant concentration and was also affected by pH of surfactant solution. The friction factor for fabrics treated with ASCO EQ85 surfactant was shown to increase with pH and better softening effect was found under acidic conditions. Half-life for foams generated with ASCO EQ85 surfactant solution increased with pH, which indicated an increase in foam stability with pH.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.132-139
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• 2005

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.120-127
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• 2011

Purpose: The purpose of this study was to examine the effects of chromium chloride addition on coloration, mechanical property and microstructure of 3Y-TZP. Materials and methods: Chromium chloride was weighed as 0.06, 0.12, and 0.25 wt% and each measured amount was dissolved in alcohol. $ZrO_2$ powder was mixed with each of the individual slurry to prepare chromium doped zirconia specimen. The color, physical properties and microstructure were observed after the zirconia specimen were sintered at $1450^{\circ}C$. In order to evaluate the color, spectrophotometer was used to analyze the value of $L^*$, $C^*$, $a^*$ and $b^*$, after placing the specimen on a white plate, and measured according to the International Commission on Illumination (CIE) standard, Illuminant D65 and SCE system. The density was measured in the Archimedes method, while microstructures were evaluated by using the scanning electron microscopy (SEM) and XRD. Fracture toughness was calculated Vickers indentation method and indentation size was measured by using the optical microscope. The data were analyzed with 1-way ANOVA test (${\alpha}$ = 0.05). The Tukey multiple comparison test was used for post hocanalysis. Results: 1. Chromium chloride rendered zirconia a brownish color. While chromium chloride content was increased, the color of zirconia was changed from brownish to brownish-red. 2. Chromium chloride content was increased; density of the specimen was decreased. 3. More chromium chloride in the ratio showed increase size of grains. 4. But the addition of chromium chloride did not affect the crystal phase of zirconia, and all specimens showed tetragonal phase. 5. The chromium chloride in zirconia did not showed statistically significant difference in fracture toughness, but addition of 0.25 wt% showed a statistically significant difference (P<.05). Conclusion: Based on the above results, this study suggests that chromium chlorides can make colored zirconia while adding in a liquid form. The new colored zirconia showed a slight difference in color to that of the natural tooth, nevertheless this material can be used as an all ceramic core material.

• Food Science and Preservation
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• v.12 no.6
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• pp.546-551
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• 2005

The new developed production process and the coating equipment were used to prepare the alginate coated rice having functional property. Then, the quality characteristics such as proximate analysis, moisture sorption properties, influence on the retrogradation, sensory evaluation were investigated. The moisture content of the alginate coated rice was $16.5-18\%$ which is $1.5\%$ higher than the normal rice. About $0.3\%$ alginate was coated on the rice by the measurement of carbohydrate content after coating with $2\%$ alginate. The rice coated with higher alginate concentration showed the higher moisture absorption. The rice coated with $2\%$ alginate solution stored $30^{\circ}C$ and $85\%$ RH conditions for 6 weeks and it increased $1.8\%$ of the moisture content The alginate coated rice has delayed the retrogradation more than 6 hrs as well as got the higher scores for the appearance, stickiness, and taste. The alginate coated rice is a good source of the fiber in the nutritional aspect and it improves the quality and functionality of the rice.

• Culinary science and hospitality research
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• v.22 no.2
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• pp.29-43
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• 2016

Pesto were prepared with five different nuts including pine nut, sunflower seed, pumpkin seed, walnut and almond to examine the antioxidant properties(total polyphenols, total flavonoids, electron donating ability) and sensory test(attribute difference, acceptance). Pesto were measured based on color value, pH, viscosity, total cell numbers for 0, 5, 10, 15 and 20 days at $4^{\circ}C$. The higher total phenol and total flavonoid content of pesto added with various nuts was higher antioxidant capacity. Basil pesto added with sunflower seeds and walnuts were considered to be more functional more than pine nuts addition. The attribute difference test results was the color intensity, nut taste, bitter taste, coarseness, oily taste, thickness were evaluated significant difference kinds of nuts. Gloss, basil flavor, nuts flavor, basil taste were not evaluated significant difference in kind of nuts. The preference test results reveal that the appearance, taste, texture and overall preference level was the highest in PNP(pinenut pesto) and SSP(sunflower seed). L value, pH, decrease while a value, b value and viscosity increased as kind of nuts in during storage. Total cell number increased and then decreased a little at a certain point. When prepared pesto, SSP(sunflower seed) was the highest in antioxidant property, and change of color value, pH, viscosity, total cell number were the lowest. In addition to the use of pine nuts, sunflower seeds have been identified are possible.

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.127-133
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• 2014

The effect of Lactobacillus-fermented solution (LFS) at a concentration of 0, 1 and 2% on shelf-life extension in terms of total aerobic bacteria and on color, lipid oxidation, and sensorial characteristics of injected chicken breast meat was tested during a 9-day storage period at $4^{\circ}C$. Throughout the whole storage days, addition of LFS showed the significant inhibition of total aerobic bacteria counts in chicken breast meat compared with that of control. However, the addition of LFS to chicken breast meat resulted in the decrease of pH, the increase of $L^*$ and $b^*$ values, and the increase of lipid oxidation in chicken breast meat when compared with those of control at any given storage period (P<0.05). In addition, the chicken breast meat added with LFS was subjected to low scores in sensorial properties such as flavor, taste, tenderness, and overall acceptability. The results suggested that LFS can be used for improving the shelf-life of chicken meat processing product, however, further study to prevent the deterioration of quality such as lipid oxidation and sensorial property is needed.

• Journal of Life Science
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• v.14 no.1
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• pp.131-140
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• 2004

T7 bacteriophage gp4 is the replicative DNA helicase that unwinds double-stranded DNA by utilizing dTTP hydrolysis energy. The quaternary structure of the active form of T7 helicase is a hexameric ring with a central channel. Single-stranded DNA passes through the central channel of the hexameric ring as the helicase translocates $5'\rightarrow3'$ along the single-stranded DNA. The DNA unwinding was measured by rapid kinetic methods and showed a lag before the single-stranded DNA started to accumulate exponentially. This behavior was analyzed by a kinetic stepping model for the unwinding process. The observed lag phase increased as predicted by the model with increasing double-stranded DNA length. Trap DNA added in the reaction had no effect on the amplitudes of double-stranded DNA unwound, indicating that the $\tau7$ helicase is a highly processive helicase. Global fitting of the kinetic data to the stepping model provided a kinetic step size of 10-11 bp/step with a rate of $3.7 s^{-1}$ per step. Both the mechanism of DNA unwinding and dTTP hydrolysis and the coupling between the two are unaffected by temperature from $4∼37^{\circ}C$. Thus, the kinetic stepping for dsDNA unwinding is an inherent property of tile replicative DNA helicase.

• Culinary science and hospitality research
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• v.18 no.4
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• pp.255-265
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• 2012

This study aimed to determine the physicochemical and sensory qualities for yogurt dressing prepared with blueberry juice(0, 10, 15, 20, and 25%). As the amount of added blueberry juice increased, citric acid, malic acid and succinic acid contents increased, but tartaric acid, lactic acid and acetic acid contents decreased. The pH of control group(3.75) was higher than that of the others(3.68-3.48). Sweetness of yogurt dressings decreased as the amount of added blueberry juice increased. DPPH radical scavenging activity of the control group was 26.44%, whereas those of yogurt dressings with blueberry juice ranged from 63.16-87.46%. Color L and b values decreased significantly, whereas a value increased significantly by addition of blueberry juice. Viscosity of the control group was lower than those of the others. The sensory property results showed that yogurt dressing with 20% blueberry juice was rated best. It was also preferred most. These results suggest 20% of blueberry juice is the best substitution ratio for yogurt dressing.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.111-115
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• 2013

The optimum synthetic conditions of poly(p-phenylphenol) by horseradish peroxidase in dioxane:water (80:20 v/v) mixtures were studied. The stability against thermal degradation and structural properties of the synthesized phenolic resins were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The synthetic yield of poly(p-phenylphenol) increased upon the increase of the amount of enzyme up to 0.25 mg HRP/mL, then leveled off for further increase of the enzyme usage. When sodium acetate (100 mM, pH 4~6) and sodium phosphate (100 mM, pH 7~9) were used as the buffering salts for the aqueous component (20% v/v), the synthetic yield of the resin increased at higher pH of the aqueous buffer. But when the pHs of the aqueous buffer were 6 and 9, the synthetic yield strongly depended on the types of the buffering salts; if sodium phosphate was used instead of sodium acetate at pH 6, the yield decreased by about 15% and if sodium bicarbonate was used instead of sodium phosphate, the yield decreased by almost 20%. When the pH range of the aqueous buffer was from 4 to 7, the addition of a radical mediator, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS), up to 2 mM improved the synthetic yield of the resin by about 10%. TGA experiments revealed that the thermal stability of the resin synthesized in dioxane:water (100 mM sodium phosphate, pH 9) (80:20 v/v) was high having the char yield of 47% upon the heating at $800^{\circ}C$. DCS results showed that the structures of the polymers synthesized in acidic aqueous buffers were different from those of the polymers synthesized in the basic aqueous buffers. However, all the synthesized resins were found to have the property of the thermosetting resins.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1084-1091
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• 2015

Aquaculture of olive flounder started in the middle of 1980's and now farming has been taken place in many places along the coastal line in Korea. The taste of olive flounder has a good chewy texture because of high collagen content, low fat content, so it is popular for sliced raw fish. Olive flounder is popular among Koreans but the consumption pattern is uniformly so as to be used as sliced raw fish but not other ways. So, now there needs to develop high valued-processed food using olive flounder. This study was set to investigate the processing of terrine by using olive flounder, in which terrine is French style meat loaf that is well favored around the world. In this study, terrine was prepared by chopping olive flounder meat with 39 g egg white and 10 mL fresh cream (per 50 g fillet) and then seasoned with 5 mL lemon juice, 5 mL brandy, 0.05 g salt and 0.05 g pepper. The 25 g of dough was placed on a vinyl wrap, put with 2 g cheese, and layered an another 25 g dough, and then rolled up and wrapped by aluminium foil. Two different cooking methods were used for terrine processing in this study. Terrine-1 was cooked by vacuum sealed in polyethylene film ($20{\times}30{\times}0.05mm$) after boiling for 5 min and stored at $-20^{\circ}C$ for 7 days. Terrine-2 was prepared by vacuum sealed in polyethylene film ($20{\times}30{\times}0.05mm$) and stored at $-20^{\circ}C$ for 7 days. After 7 days, Terrine-1 was thawed and then heated up in microwave for 2 min (Sample-1), while Terrine-2 was thawed and then boiled in water for 5 min (Sample-2). Viable bacterial count, chemical composition, pH, salinity, hardness, TBA, free amino acid content, and sensory evaluation were measured for both Sample-1 and Sample-2. Especially, the scores of sensory evaluation of Sample-2 is slightly higher than that of Sample-1. On the other hand, there were no significant differences on color, odor, taste, texture, and overall acceptance between Sample-1 and Sample-2.