• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.534-542
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• 2006

The protein contents of soy protein isolate (SPI) and soft wheat flours were 83.5% and 8.5%, respectively. The addition of SPI increased the protein content but decreased the sedimentation value. Alkaline water retention capacity (AWRC) value increased with SPI addition and was highly correlated with protein content. Increasing SPI flour content significantly decreased the maximum, minimum and final viscosities. Mixograph peak time was positively correlated with protein content and AWRC. The PH and specific gravity of the cake batter increased with increasing SPI content. The SPI addition reduced the loaf and specific loaf volume compared with soft wheat flour. The lightness of the cake crust decreased, while the redness and yellowness increased, with SPI flour addition. SPI addition resulted in a decrease of overall acceptability, but an increase in hardness.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.108-117
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• 2017

Laver, Porphyra, is distinctive for its high content of proteins and polysaccharides such as porphyran and hemicellulose. The chemical properties of the polysaccharides extracted with different extraction methods such as hot water, dilute acid(pH 4.0) or alkali solution(2N NaOH) were examined to investigate the suitable extraction conditions for porphyran and hemicellulose from laver. For porphyran extraction, dilute acid solution was more preferable to hot water and alkali solution because of its higher 3,6-anhydrogalactose content and lower protein content. However, alkali solution was more suitable to extract the hemicellulose because of higher mannose content indicating the extraction of mannan. To decrease contamination of the polysaccharides with protein, the dried lavers were pretreated with enzymes (Protamex, Flavourzyme, Alcalase, Viscozyme) before hot water extraction. All enzyme pretreatments increased the yield of polysaccharides by compared with control (enzyme unpretreated) and Flavourzyme pretreatment was most effective to decrease protein contamination in the polysaccharide. All viscosities of porphyran solutions pretreated by enzymes were lower compared to the control porphyran solution and showed pseudoplastic behavior with yield stress. In case of alkali extraction of residues obtained after enzyme hydrolysis and hot water extraction, protease pretreatment increased the mannose contents in the polysaccharide while the xylose content was increased by Viscozyme pretreatment.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.31-39
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• 2020

The effects of heat-moisture treatment (HMT) on the functional properties of high amylose rice starches (HARSes) purified from Korean rice varieties (A-type Goami and Singil and B-type Dodamssal and Goami2) were investigated. HMT was accomplished with moisture contents of 18 and 27% and heated at 100℃ for 16 h. While the amylose content, swelling power and solubility decreased after HMT, the water binding capacity and resistant starch (RS) content increased with increasing moisture content after HMT. The X-ray diffraction patterns of all HARSes did not change after HMT, but a decrease in the intensity of peak at 2θ=5° was observed in B-type HMT HARSes. While the starch granules aggregated after HMT, their shape and size remained unchanged. B-type HARSes exhibited higher gelatinization temperatures and lower pasting viscosities than A-type HARSes following HMT. The results, thus, suggest that while the crystalline intensity of B-type Dodamssal and Goami2 rice starches did not change after HMT, the RS content, water binding capacity, and pasting temperatures of all HARSes increased with increasing moisture content after HMT.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.524-536
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• 1994

Chitosan is known to be a good biocompatible natural polymer. Polyethyleneglycol monomethacrylates(PEGM) were grafted onto chitosan and their reaction conditions and properties of the graft polymers obtained were estimated. Using ceric ammonium nitrate(CAN) as the initiator, the optimum condition for graft polymerization was determined amount of the initiator and monomer concentrations and reaction time. Grafting yields such as total conversion, the percentage of grafting and the efficiency of grafting were calculated and examined the optimum reaction condition for high grafting yields. The percentage of grafting and total conversion were maximum at condition that the concentration of initiator was $4{\sim}5{\times}10^{-3}M$, the concentration of monomer was 0.5~0.6M, the reaction time was 2~3 hours and the reaction temperature was about $40^{\circ}C$. Thermal characteristics, solubility for chitosan solvents and inherent viscosity of synthesized graft copolymers were investigated. In high initiator concentration, characteristics of chitosan were greatly diminshed. In case of inherent viscosities, chitosan-g-PE-90 was 2.81 dl/g, chitosan-g-PE-200, 3.01dl/g and chitosan-g-PE-350, 4.93dl/g. And a tendency of viscosity increase depending on the length of ethylene oxide residue was confirmed. Degree of swelling, tensile strength, elongation of membrane prepared from graft copolymers were determined. Properties of graft copolymers were affected by percentage of grafting and length of ethylene oxides residue in polyethylene glycol monomethacrylates. Tensile strength, elongation and degree of swelling of graft copolymers were remarkably improved than chitosan. As percentage of grafting increased, the amount of drug permeation was also increased.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.237-244
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• 2017

Hyperbranched liquid crystalline polymers with azomesogenic and cholesteryl groups in their terminal positions were designed and synthesized by direct polycondensation reaction. The chemical structures and thermal and mesomorphic properties of the synthesized polymers were investigated by FT-IR, $^1H-NMR$, differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and polarizing optical microscopy (POM). The inherent viscosities (${\eta}_{inh}$) of the polymers were measured to be between 0.30 and 0.50 dL/g in phenol/p-chlorophenol/1,1,2,2-tetrachloroethane (25/40/35 = w/w/w). The degree of branching (DB) in these polymers ranged from 0.37 to 0.75; they, as amorphous polymer, showed glass transition temperatures ranging from 80 to $120^{\circ}C$; the polymers readily dissolved in most of the organic solvents used in the experiments. Only hyperbranched polymers with a cholesteryl group as their mesogenic group showed liquid crystalline phases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.6029-6038
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• 2013

In this study we attempt to modify the backbone structure and improve processibility of PBO having high melting and glass transition temperature. A series of aromatic poly(o-hydroxyamide)s(PHAs) were synthesized by direct polycondensaton of diacides containing diimide unit with two types of bis(o-aminophenol)s including 3,3'-dihydroxybenzidine and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane. PHAs were studied by FT-IR, $^1H$-NMR, DSC and TGA. PHAs exhibited inherent viscosities in the range of 0.34~0.65 dL/g at $35^{\circ}C$ in DMAc solution. The PHA 1 and 6F-PHA 6, introducing o-phenylene unit in the main chain showed excellent solubilities in aprotic solvents such as NMP etc. However, the PHA 3, having p-phenylene unit was not even dissolved perfectly with LiCl salt. 6F-PHAs were readily soluble at room temperature in aprotic solvents except 6F-PHA 3. But they showed better solubility than that of PHAs. The polybenzoxazoles(PBOs) were quite insoluble in other solvents except partially soluble in sulfuric acid. PBOs exhibited relatively high glass transition temperatures(Tg) in the range of 306~$311^{\circ}C$ by DSC. The maximum weight loss temperature and char yields of PHA3 and 6F-PHA3 showed the highest values of $658^{\circ}C$ and $653^{\circ}C$, 62.6 % and 62.1 %, respectively.

• Journal of KSNVE
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• v.6 no.1
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• pp.107-114
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• 1996

The damping characteristics of a cylindrical structure containing oil and bearing balls is investigated for external bending forces. The experimental data obtained through the use of bearing balls with viscous oil in a column is given and analyzed. The viscous action of the oil and inertia effects of the balls on the inside of column create a drag force. The drag force dampens the vibration of the column. This study aims to search for an optimum combination of oil and balls which would produce maximum damping. Machining oils of various viscosities along with ball bearings of various sizes place inside cantilevered aluminium tubes of various diameters to create a rig on which the damping properties of the oil and balls can be studied. The contileved tubes are studied in both horizontal and vertical positions in order to gauge the effect of gravity on the system. The actions of the ball in the column and damping characteristics are investigated according to the dimensionless terms. The Buckingham theorem is used to reduce the variables and to predict the damping of an oil ball column. Though the damping ratio remains fairly constant in the horizontal position of column, the damping ratio begins to increase as the ratio of the number of balls and column length rise above 0.28 in the vertical position of oil ball column. The ratio of the ball diameter to column diameter influences the damping ratio with an optimum diameter ratio. Slenderness ratio and gravity effects on the damping ratio ane investigated.

• 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.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.47-53
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• 1987

The physicochemical properties of kidney bean crude and refined starch were investigated. The results were as follows : Amylose content of refined starch was 77%. Blue values of crude and refined starch were 0.375 and 0.410, respectively. Ferricyanide numbers of crude and refined starch were 1.00 and 1.94, respectively, and alkalinumbers of crude and refined starch were 8.67 and 6.90, respectively. Amylose had molecular weight of 18067 and degree of polymerization was 112. Amylopectin had degree of branching of 3.7 per 100 glucose units and glucose units of 27 per segment of amylopectin. Water binding capacities of crude and refined starch were 202.1% and 169.4%, respectively. Both swelling powers of crude and refined starch were increased rapidly from $70^{\circ}C$ to $90^{\circ}C$ and their curves showed a single-stage pattern. The optical transmittance of 0.2% crude starch suspension was increased rapidly from $80^{\circ}C$ to $83^{\circ}C$ and that of 0.2% refined starch suspension was increased rapidly from $77^{\circ}C$ to $83^{\circ}C$. Brabender hot-paste viscosities of crude and refined starch at 6% and 8% concentation (solid basis) showed the similar amylogram patterns of c type with no peak vircosity.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.31-36
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• 1987

The purpose of this study is to investigate the physicochemcal Properties of the cowpea crude and refined starch and to present the basic data for physicochemical factor which gives the properties of Mook to cowpea starch gel. Water binding capacity of crude starch was 235. In and that of refined starch was 186.0%. The pattern of change in swelling power and solubility for increasing temperature started to increase at $60^{\circ}C$ and increased rapidly from $70^{\circ}C$, for both of crude and refined starch. The optical transmittance of 0.2% crude and refined starch suspensions were increased from $65^{\circ}C$ and showed rapid increasement during 68~$80^{\circ}C$, and their curves showed two-stage processes. The gelatinization pattern for 6n crude and refined starch suspensions were investigated by the Brabender amylograph. The corves showed the pasting temperature of $72.0^{\circ}C$ and $72.1^{\circ}C$, peak height of 11303.U. ($88.0^{\circ}C$) and 970 B.U. ($83.5^{\circ}C$) for crude and refined starch, respectively, and both showed high viscosities when cooling. Blue values for crude and refined starch were 0.369 and 0.376 respectively. Alkali number of crude and refined starch were 7.77 and 7.34, and reducing values were 3.60 and 2. 10, respectively. Amylose content of cowpea starch was 33.7%. Periodate oxidation of the starch fractions resulted that amylose had the average molecular weight of 23590, degree of polymerization of 146 and amylopectin had the degree of branching of 3.42, glucose unit per segment of 29.