• Journal of the Society of Cosmetic Scientists of Korea
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• v.20 no.1
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• pp.37-51
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• 1994

Empty cross-linked chitosan microcapsule was prepared by chemical cross-linking reaction using glutaraldehyde(GA). Chitosan bead was also prepared by coacervation method using sodium hydroxide. The technique involves the formation of a chitosan solution in the discontinuous phase of W/O emulsion. The factors influencing the emulsion stability have been examined to establish optimum conditions Chitosan microcapsules were useful for encapsulation of biological materials, and chitosan bead was useful to prepare the biologically active peptide-bound polysaccharide. As a model compound Gly-His-Lys, cell growth factor, was successfully coupled to chitosan bead.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.806-813
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• 2000

Attempts were made to evaluate possibilities of adding water soluble chitosan to milk for improving functionality of milk, and physico-chemical and sensory properties of chitosan added milk were studied. pH and acidity of milk with ethyl alcohol washed chitosan were close to those of control. Color and consistency of chitosan added milk were better with chitosan of lower molecular weight than with high molecular weight. Chitosan of high molecular weight resulted in increased consistency and browning of milk. Milk with less than 1.0% chitosan could be sterilized at $73^{\circ}C$ for 15 sec. with minimum protein coagulation and increase of consistency. Low molecular weight chitosan$(MW\;0.2{\sim}3\;kDa)$ accelerated the growth of Bifidobacterium bifidum, showing 10 times more cell population after 32 hrs incubation. Sensory tests showed that adding chitosan to the regular city milk resulted in significant difference in color and chemical off-flavor(p<0.05). When chitosan was added to coffee milk, there was no significant difference in sensory quality from control. The storage test showed that pH, acidity, consistency and color of coffee milk with 0.5% chitosan did not change markedly during 30 days storage at 0 and $5^{\circ}C$, but changed rapidly after 16days storage at $10^{\circ}C$. Bacterial counts increased when storage temperature was high, and the growth of bacteria was delayed in coffee milk with chitosan.

• Membrane Journal
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• v.23 no.6
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• pp.418-424
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• 2013

The PDMS-chitosan composite membranes were prepared by addition of 0.02~0.60 wt% chitosan to PDMS. In order to investigate the characteristics of these membranes, we used the analytical methods such as SEM and TGA. Gas permeation experiments was performed in $30^{\circ}C$, $4kg/cm^2$, the permeability and selectivity of $H_2$ and $N_2$ according to content change in composite membrane were investigated. The permeability of $H_2$ and $N_2$ for the PDMS-chitosan composite membranes increased when 0~0.20 wt% chitosan was added, and then decreased at higher wt% as chitosan content increased. The selectivity ($H_2/N_2$) of PDMS-chitosan composite membranes decreased when 0~0.20 wt% chitosan was added, and then increased as chitosan content increased. In the case of PDMS-chitosan in which chitosan was inserted to PDMS, thermal stability of PDMS was enhanced. Based on SEM observation, as the chitosan content within PDMS increased, the surface of the composite membranes became coarse and began to form holes.

• Korean Journal of Human Ecology
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• v.14 no.2
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• pp.321-330
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• 2005

The antimicrobial activity of PHB/chitosan films and the quality of white bread packaged with the films were investigated. Chitosan film showed the highest antimicrobial activity and PHB(L) film also showed high antimicrobial activity against Fusarium solani KCTC 6636 and Penicillium citreonigrum KCTC 6927. White bread packaged with chitosan film had good moisture retention. $L^*\;and\;b^*$ of white bread increased but $a^*$ did little change during storage regardless of the film kind. The TBA values of white bread packaged with chitosan or PHB(L) film slowly increased during storage. The springiness of white bread packaged with PHB(M), PHB(L) and chitosan film was high. The colony forming units of microorganisms for white bread packaged with chitosan film were low during storage. Therefore, PHB(M), PHB(L) and chitosan films were superior to PHB(H) and PHB films as package material for white bread.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.118-128
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• 1996

N-methyl, N-butyl and N,N-dibutyl chitosan derivatives were prepared by Schiff's base formation and hydrogenation in aqueous media. Furthermore quaternization of the chitosan derivatives was performed in N-methyl-2-pyrrolidone using methyl iodide to obtain water soluble cationic polyelectrolytes. It was confirmed that O-alkylation was occured as well as selective N-alkylation in these reactions. Chitosan and chitosan derivatives with quaternary ammonium iodide showed high flocculation power as the cationic flocculant. When tested on paper mill waste water, they showed high flocculation power, independing of pH range. The flocculation power was increased as the N-alkyl chain length was increased. Among them, N-butyl dimethyl chitosan ammonium iodide showed better flocculation power than chitosan. But, N,N-dibutyl-N-methyl chitosan ammonium iodide showed less flocculation powre than chitosan itself.

• KSBB Journal
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• v.10 no.5
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• pp.525-532
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• 1995

Chitosan derivative, of a sulfated N-acetyl chitosan was synthesized, and the inhibitory effects of this compound on the experimental and spontaneous lung metastallc B16/BL6 melanoma bearing mice were investigated. Position of substitution with sulfate in water-soluble sulfated derivatives of chitosan were analysed by 13C-nmr. The structure of N-acetyl chitosan 3,6 0-disulfate were confirmed. The tumor growth inhibition of B16/BL6 melanoma cells has been shown at the highest level of 77.6% when sulfated N-acetyl chitosan were administered at the dose of 100mg/kg. In the lung metastasls, the sulfated N-atetyl chitosan was administered to C57BL/6B mice bearing B16/BL6 melanoma cells by I.V. injection and the number of metastasis foci of melanoma were decreased by the dose dependent manner ranging from 20 to 100mg/kg. In the spontaneous metastasis, I.V. administrations of sulfated N-acetyl chitosan after tumor inoculation resulted in marked reduction of metastatic colonies. A sulfated N-acetyl chitosan was able to partially inhibit the tumor cell adhesion by migration to laminin. These results suggested that chitosan derivative, a sulfated N-acetyl chitoasn was able to inhibit to the experimental and spontaneous metastasis models as well as cell adhesion ability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.865-869
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• 2001

Isolation and identification of the major bacteria causing spoilage of buckwheat starch jelly, and the effects of chitosan concentrations (0, 0.5, 1.0, 1.5, 2.0%) on shelf-life and quality of buckwheat starch jelly were investigated. Eight strains were isolated from spoiled buckwheat starch jelly and identified as Serratia liquefaciens and Staphylococus lentus. During storage of buckwheat starch jelly for 6 days at 18$^{\circ}C$, viable counts were lower at higher chitosan concentrations, especially at 1.5% and 2.0%. Water activity was less reduced at higher chitosan concentrations. Color L* value decreased, and a* values increased slightly with storage periods. In sensory evaluation, buckwheat starch jelly containng 1.0% chitosan was evaluated the best, with lower overall acceptability at higher chitosan concentrations. Buckwheat starch jelly containing 1.0% chitosan showed a longer shelf-life by 1~2 days than the control.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1269-1276
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• 2003

In order to know the effect of atuoclaving on the heavy metal removal using chitosan, lead removal capacities and removal rates by various chitosans in aqueous solution were compared according to the various autoclaving time. The lead removal efficiencies and removal rates by the autoclaved chitosan were found to be on the order of 15 min(98％) ＞ 10 min(95％) ＞ 30 min(83％) ＞ 5 min(53％) ＞ 60 min(47％) ＞ 0 min(22％) chitosan. The molecular weight of chitosan was decreased by the increase of autoclaving time. Therefore, the heavy metal removal capacity was not well correlated to the molecular weight. Langmuir isotherm was well fitted to experimental results of equilibrium adsorption on chitosan. In order to examine the process of lead removal by the autoclaved chitosan, TEMs, SEMs and FT-IR analyses were used. The surface of autoclaved chitosan was much more porous and the lead removal was mainly occurred on the surface of chitosan. The structure of autoclaved chitosan was same as that of controlled chitosan.

• Textile Coloration and Finishing
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• v.11 no.3
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• pp.32-40
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• 1999

Chitosan fiber was prepared by wet spinning with various draw ratio. Chitosan fiber was coated with f-carboxymethyl keratein(SCMK) by extruding chitosan solution into 1 M NaOH solution containing 1% SCMK. Among three chitosan used in this study(chitosans of 5 cps, 50 cps, 100 cps), 50 cps chitosan gave the best tenacity and optimum concentration was 5%. SCMK coating increased the tenacity of chitosan fiber. Regardless of SCMK coating, tenacity and elongation of both chitosan fibers were increased with the increase of draw ratio. Chitosan fiber showed antimicrobial activity against Staphyloccus aureus showing 66∼72% of bacteria reduction rates. On the other hand, chitosan fiber coated with SCMK didn't show any antimicrobial activity.

• Journal of Nutrition and Health
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• v.38 no.9
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• pp.689-697
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• 2005

This study was conducted to fine out the preventive effects of chitosan and chitosan oligomer on the disorders of hepatic functions and lipid metabolism induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) using adult male rats (SD) for four weeks. Rats were fed chitosan ($4\%$) or chitosan oligomer ($4\%$) diets respectively before 3weeks of TCDD treatment (50 ug/kg BW) by intraperitoneal injection and then continually supplied these diets for one week until being sacrificed. The elevation of serum total and LDL cholesterol levels induced by TCDD treatment was significantly reduced in the rats fed chitosan diets. The increment of liver triglyceride levels caused by TCDD treatment was tended to suppress in all rats fed chitosan and chitosan oligomer diets. Fecal total lipid and cholesterol excretion were high levels in the rats fed chitosan diets. The hepatic cytosolic catalase activities significantly decreased by TCDD treatment appeared recovering trend by chitosan diets. In hepatic microsomal cytochrome p-450, NADPH cytochrome p-450 reductase, ethoxycoumarin-o-deethylase (ECOD) and benzphetamin N-demethylase (BPND) chitosan than chitosan oligomer diets apparently decreased the increasing levels by TCDD treatment. In histochemical observation the fat droplets and apoptosis of hepatocytes by TCDD treatment were markedly alleviated by chitosan and chitosan oligomer diets. These results indicate that chitosan, more than chitosan oligomer can exert preventive effects on some disorders of hepatic functions and lipids accumulation by TCDD.