• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.306-310
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• 2005

The comparison in release rate constant and properties of extracts from extruded raw ginseng and extruded white ginseng was conducted to apply extrusion process for manufacturing of released ginseng tea bag. Dry raw ginseng and white ginseng powder were extruded at 20∼30% moisture content and 200∼300 rpm by using an experimental twin-screw extruder. Browness and redness (both indicated the releasing of saponin and ginsenosides) were increased with the increase in the screw speed and the decrease of moisture content. Crude saponin and water solubility index (WSI) of both ginseng also share the same behaviour against the level of screw speed and moisture content, as well as browness and redness. The particle size effects of extruded raw ginseng at 20% and 28% moisture content on absorbance of released extract at 260 up to 560 nm, WSI, and water absorption index were determined. While particle size decreased from 800∼1000 nm to 200∼500 nm, absorbance and WSI are decreased. Absorbance and WSI shown increasing level while moisture content was decreased. In conclusion, the formation of pores by expansion and disruption of cell wall in extrusion cooking were obviously responsible to increase the amount of released extract of extruded ginseng and its WSI as well. The extrusion process turns out be the efficient process for manufacturing of commercial ginseng tea product than those of other thermal processes.

• Clean Technology
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• v.18 no.1
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• pp.57-62
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• 2012

Aqueous poly (vinyl alcohol) (PVA) solution was modified by using hydrophobic vinyltriethoxysilane (VTEOS) and then adding different amounts of poly (acrylic acid) (PAA) to the resulting solution. Thermal and mechanical properties, contact angle, water vapor transmission rate (MVTR) and oxygen gas transmission rate ($O_2TR$) of the film samples fabricated by these solutions were investigated. The glass transition temperature (Tg) of the VTEOS-modified films was sightly increased and the value remained unchanged according to the amount of PAA. The tensile strength of the VTEOS-modified films was found to be 9.48~10.72 $kg/mm^2$ which showed no significant difference compared with that of PVA. The film prepared with VTEOS-modified PVA/PAA (= 90/10), of which the swelling and solubility were measured to be 198% and 0%, respectively, showed improved water-resistance. The MVTR and $O_2TR$ for the PET film (thickness 50 ${\mu}m$) coated with VTEOS-modified PVA/PAA (= 90/10) film (thickness 2.5 ${\mu}m$) were measured to be 11.04 $g/m^2/day$ and 3.1 $cc/m^2/day$, respectively.

• Journal of Plant Biology
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• v.24 no.1
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• pp.31-45
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• 1981

The purpose of this study aimed to study effects of fire on vegetation and soil properties after the first growing season in Mt. Chiak. 1. With the basis of importance value of species in each stand, status of species was assessed for three categories; Increaser species, Decreaser species, and Neutral species. 2. Biomass was 2.2 times higher on burned area than unburned. This indicates that biomass was remarkably increased after fire. 3. To evaluate similarity, coefficients of similarity among communities were obtained, and correlation coefficients were also estimated. These indices showed that burned and unburned community were markedly different.. $B_1$-stand and $B_1$-stand appeared most similar to each other among stands. 4. Species diversity was greater in burned than unburned stands. 5. Soil pH value and organic matter content in burned area were significantly higher than those in unburned area. However, soil water content was lower in burned area. There was no effect of burning on soil pH value and water content at 15~20 cm depth of soil. 6. All chemical compositions except sodium were much higher in soil surface. The decreases in sodium levels at surface were probably resulted from the rapid leaching due to the increased solubility and decreased capacity for adsorption of sodium in comparison with potassium or calcium. Among chemical compositions of soil amount of nitrogen showed least difference between the burneb and unburned surfaces soil.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1138-1143
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• 1997

This study was carried out to investigate the meat color and water holding capacity (WHC) characteristics of PSE, RSE (reddish-pink, soft, exudative), RFN (reddish-pink, firm, non-exudative) and DFD pork quality, also the relationship of lightness $(L^*-value)$ and WHC to drip loss were examined. When WHC in M. longissimus dorsi muscle by filter paper press method was measured at 45 min postmortem (45 min p.m.), DFD meat indicated the highest WHC, RSE and RFN pork were significantly different (p<0.05). WHC measured at 24 hr postmortem were not significantly different between RSE and RFN pork (p.0.05). Drip loss (%) were significantly different among the four quality group, but cooking loss (%) of PSE, RSE and RFN pork were not significantly different, except DFD. PSE pork indicated the lowest salt soluble protein solubility. The correlation between drip loss and $L^*-value$ was r=0.61, drip loss increased with increasing $L^*-value$. Also drip loss were moderately correlated with $WHC_{4.5\;min\;p.m.}$ (r=-0.47), with $WHC_{24\;hr\;p.m.}$ (r=-0.52). When drip loss was predictable from $L^*-value$ and WHC, $L^*-value$ was superior to evaluation by WHC.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.757-762
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• 2005

Characteristics of cereals prepared by extrusion-cooking and freeze-drying were compared. Parameters used were water solubility index (WSI), water absorption index (WAI), paste viscosity, and sterilization. Variables for extrusion process were barrel temperature at die section (70, 90, and $110^{\circ}C$) and moisture content (25 and 30%). WAI and WSI of extruded cereals were higher, whereas trough, breakdown, and final viscosity were lower than those of raw and freeze-dried cereals. Plate counting revealed no microbes in extruded cereals, whereas microbe colony was observed in freeze-dried cereals. Extrusion-cooking at low temperature resulted in better sterilization of microbes than freeze-drying for preparation of instant cereal drinks.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.108-118
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• 2001

This study was performed to investigate the bioconcentration of IBP, methidathion and piperophos. The BCFs(bioconcentration factor), depuration rate constants for three pesticides in zebrafish(Brachydanio rerio) were measured by OECD guideline 305. The concentration of test pesicides were one-hundredth and one-thousandth concentration of 96-hrs L $C_{50}$ in accordance with OECD guideline 305. The results obtained are summarized as follows: The average BCF values of IBP were 5.31(n=4) and 7.30(n=4) at one-hundredth and one-thousandth concentration of 96-hrs L $C_{50}$ . The average BCF values of methidathion were 8.72(n=4) and 11.25(n=4), the average BCF values of piperophos were 34.30(n=4) and 42.60(n=4). Depuration rate constants of IBP were 0.09( $h^{-1}$ ) and 0.08( $h^{-1}$ ), half-life of IBP were 7.70 and 8.66 at each tested concentration. The concentrations of IBP in zebrafish at low and high concentrations rapidly decreased after 12(0.243$\mu\textrm{g}$/g) and 12 hours(0.040$\mu\textrm{g}$/g). Depuration rate constants of methidathion were 0.40( $h^{-1}$ ), half-life of methidathion were 1.73 at one-hunderdth and of 96-hrs L $C_{50}$ , repectively. The concentrations of methidathion in zebrafish at high concentrations rapidly decreased after 6 hours(0.18 $\mu\textrm{g}$/g). Depuration rate constant of low concentration was no measured because methidathion in zebrafish was depurated in 6 hours. Depuration rate constants of piperophos sere 0.15( $h^{-1}$ ) and 0.44( $h^{-1}$ ), half-life of piperophos were 4.62 and 1.58 at each tested concentration. The concentrations of piperophos in zebrafish at los and high concentrations rapidly decreased after 12(0.26$\mu\textrm{g}$/g) and 6 hours(0.015 $\mu\textrm{g}$/g). It was suggested that high BCF of piperophos was due to high Kow(octanol-water partition coefficient). The possibility of bioconcenration was not likely to be high because of its $K_{DEP}$(depuration rate constant) in the evniroment. It was suggested that low BCF of methidathion showed lowest Kow as well as the most rapid $K_{DEP}$. Therefore, the possibility of bioconcentration was not occured in the enviroment. It was suggested that the BCF dtermined for IBP was lower than that of other pesticides due to high Sw(water solubility), show $K_{DEP}$. Therefore, IBP revealed little bioconcentration effect on in aquatic ecosystem.ystem.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.290-299
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• 2006

Objectives: The purpose of this study is to evaluate the effect of ethylene glycol analogs on modulus of elasticity and ultimate tensile strength of moist, demineralized dentin matrix. Methods: Dentin disks 0.5 mrn thick were prepared from mid-coronal dentin of extracted. unerupted, human third molars. 'I' beam and hour-glass shaped specimens were prepared from the disks, the ends protected with nail varnish and the central regions completely demineralized in 0.5M EDTA for 5 days. Ultimate tensile stress (UTS) and low strain modulus of elasticity (E) were determined with specimens immersed for 60 min in distilled water $(H_{2}O)$, ethylene glycol $(HO-CH_{2}-CH_{2}-OH)$, 2-methoxyethanol $(H_{3}CO-CH_{2}-CH_{2}-OH)$, and 1,2-dimethoxyethane $(H_{3}CO-CH_{2}-CH_{3}-OCH_{3})$ prior to testing in those same media. Modulus of elasticity was measured on the same specimens in a repeated measures experimental design. The results were analyzed with a one-way ANOVA on ranks, followed by Dunn's test at ${\alpha}\;=\;0.05$. Regression analysis examined the relationship between UTS or E and hoy's solubility parameter for hydrogen bonding $({\delta}_{h})$ of each solvent. Results: The UTS of demineralized dentin in water, ethylene glycol, 2-methoxyethanol, and 1,2-dimethoxyethane was 24 (3), 30 (5), 37 (6), and 45 (6) MPa, ${\times}$ (SD) N = 10. Low strain E for the same media were 16 (13), 23 (14), 52 (24), and 62 (22) MPa. Regression analysis of UTS vs ${\delta}_{h}$ revealed a significant $(p\;<\;0.0001,\;r\;=\;-0.99,\;R^{2}\;=\;0.98)$ inverse, exponential relationship. A similar inverse relationship was obtained between low strain E vs ${\delta}_{h}\;(p\;<\;0.0005,\;r\;=\;-0.93,\;R^{2}\;=\;0.86)$. Significance: The tensile properties of demineralized dentin are dependent upon the hydrogen bonding ability of polar solvents $({\delta}_{h})$. Solvents with low ${\delta}_{h}$ values may permit new interpeptide H-bonding in collagen that increases its tensile properties. Solvents with high ${\delta}_{h}$ values prevent the development of these new interpeptide H-bonds.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.778-784
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• 2005

It has been found that the addition of cosurfactant is necessary in order to expand three phase region containing middle phase microemulsion in ternary systems containing alkyl ethoxylate (AEO) nonionic surfactant, commercial lubricant and water. Phase behavior in the surfactant systems with addition of cosurfactant over a temperature range of 30 to $60^{\circ}C$ showed different trends depending on surfactant, temperature and chain length of alcohol added. For the $C_{12}E_4$ system, addition of n-pentanol and n-hexanol both produced a three phase region over a wide range of temperatures but the middle-phase formed was found to be a $L_3$ or D' phase which would not facilitate solubilization of high molecular weight lubricants. On the other hand, for the $C_{12}E_5$ system, the middle-phase microemulsion was found to be formed with addition of a rather long-chain alcohol such as n-hexanol, n-heptanol, n-octanol, or n-nonanol. The results shown with the addition of cosurfactant was understood in connection with interfacial tension measurements and composition analysis. The inability of the hydrocarbon region of the surfactant films to incorporate the large lubricant molecules and high solubility of a hydrophobic surfactant are thought to be the chief reasons for poor solubilization with D' phase.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.356-363
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• 2009

This study was carried out to investigate the effect of hot boning and curing condition on the quality characteristics of ground chicken breast. Treatments were cured by four conditions follows; control (general curing method), T1 (after hot-boning and then immediately cured), T2 (after hot-boning and immediately cured, then frozen), and T3 (after hot-boning, immediately frozen, refrigerated and then cured). The pH of chicken breast in the state of pre-rigor was 6.22. The pH of cold storage or freezing chicken breast meat respectively were 5.70 or 5.61. The pH of T1 and T2 treatments were significantly higher than those of control and T3 treatment (p<0.05). After stored for 1 wk, the pH value of T1 treatment had a higher value than those of other treatments. T1 treatment had the highest water holding capacity and the lowest cooking loss among all treatments, regardless of the cooking methods. The reduction in diameter for T1 and T2 treatments was lower than those of control and T3 treatment (p<0.05). T1 treatment had the lowest fat loss and moisture loss among all treatments, and the emulsifying capacity of T1 treatment was the highest. The protein solubility of T1 treatment was significantly lower than that of T3 treatment.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.169-178
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• 1996

Target parameters such as water solubility index (WSI), intrinsic viscosity (IV), water holding capacity (WHC), oil holding capacity (OHC), soluble dietary fiber (SDF) and microstructure were investigated on three different screw configurations during twin-screw extrusion of wheat bran. WSI of raw wheat bran (RWB) was 13.7%, while that of extrudates ranged $16.3{\sim}23.2%$ when extruded using screw configurations with 5 reverse screw elements (RSE). It was found that the moisture content of RWB greatly affected WSI of extrudates. IV of wheat bran extrudates increased from 10.6 ml/g of RWB to $37.86{\sim}44.37\;ml/g$ of extrudates extruded using 3, 4 and 5 RSE, whose trend was highly related to the moisture content of RWB and the extrusion pressure. Multiplication of IV and soluble solid (SS) content exhibited good correlation $(R^2=0.85)$ with specific mechanical energy (SME). The results suggested that SS and molecular size are an important factor governed by the SME in solubilization of wheat bran. WHC increased with increasing feed rate and moisture content, while OHC decreased. SDF increased from 2.68% of RWB to $4.32{\sim}6.48%$ of extruded wheat bran, indicating the significant breakdown of cell wall components. Microstructure of the extrudates showed the distinct patterns of degradation and solubilization of cell wall structure, depending on the moisture content of RWB.