• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.47-56
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• 1998

When rats are exposed to cadmium in their diet, the cadmium accumulates in the liver. This study was carried out to investigate the effect of chitin, chitosan and dithiocarbamate chitosan on the cadmium accumulation in liver of rats. For this experiment, 10 male Sprague-Dawley were used. The experimental groups were divided into four independent groups which were one control group and three experimental groups by cadmium alone treatment or chitin, chitosan and dithiocarbamate chitosan with cadmium. In order to investigate the eliminative effect of chitin, chitosan and dithiocarbamate chitosan on the cadmium accumulation in liver of rats, the cadmium concentration, the metallothionein level and the enzyme activitys were measured. The results obtained revealed the eliminative effect of cadmium in liver of rats by chitin, chitosan and dithiocarbamate chitosan. The effect of chitin on the cadmium elimination was less than that of chitosan and dithiocarbamate chitosan. Also it shows that the eliminative effect of cadmium by dithiocarbamate chitosan was the highest.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.319-327
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• 2000

This study was conducted to prolong the edible period of Kimchi by adding chitosan (0.25, 0.5%) and sodium salts of various organic acids(0.01~0.04M citrate, malate, lactate) . The edible period was estimated by measuring changes in pH. titratable acidity(TA), PH/TA ratio, ascorbic acid content and pectin fraction during Kimchi fermentation at 2$0^{\circ}C$. The results were compared by estimating the maturity of Kimchi fermentation. Kimchi with the chitosan showed higher pH and titratable acidity throughout the fermentation period than that without chitosan. The pH decreased during the fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-citrate, 0.5% chitosan+Na-malate and 0.5% chitosan+Na-lactate. But the titratable acidity increased in the order of control, 0.5% chitosan+Na-malate, 0.25% chitosan. 0.5% chitosan+Na-citrate, 0.5% chitosan and 0.5% chitosan+Na-lactate. The PH/TA ratio decreased in the order of control, 0.25% chitosan, 0.5% chitosan+Na-malate, 0.5% chitosan, 0.5% chitosan+Na-citrate and 0.5% chitosan+Na-lactate. Ascorbic acid content in Kimchi was the highest at the 3rd day and then decreased during fermentation. Ascorbic acid content in Kimchi containing 0.5% chitosan and organic acid salts was higher than others. Alcohol insoluble solids( AIS ) in Kimchi decreased during fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-palate. 7.5% chitosan+Na-lactate and 0.5% chitosan+Na-citrate. During fermentation, hot water soluble pectin (HWSP) of control increased, whereas HCI soluble pectin (HCISP) decreased. By addition of chitosan, however, the results became reverse. Chitosan addition appeared to be effective in improving preservation quality of Kimchi during fermention. The edible period become extended by using chitosan plus organic acids instead of using chitosan only. Overall. addition of 0.5% chitosan+Na-lactate seemed most effective in prolonging the edible periods during Kimchi fermentation.

• Journal of Nutrition and Health
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• v.31 no.2
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• pp.143-152
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• 1998

This study was conducted to investigate the effects of chitosan, chitosan oligomer and beef tallow of different levels on lipid metabolism in rats, Seventy male rats of the Sprague-Dawley strain were blocked into 10 groups according to body weight , and were raised for 4 weeks. Dietary fat levels were 20% en and 40% en, and chitosan and chitosan oligomer were given at levels of 05, 3%, and 5%(wt/wt) of diet. The results are summarized as follows, chitosan oligomer supplement decreased serum total lipid, as chitosan 양, and exhibited a tendency to decrease serum total cholesterol. Chitosan oligomer supplement tended to increase the HDL cholesterol ; total cholesterol ration as chitosan did. Liver total lipid and triglyceride concentration were lower in high fat groups than in low fat groups. Liver total lipid concentrations was decreased slightly by chitosan and sigfnificantly by chitosna ligomer. Epididymal fat pad total lipid. total cholesterol and triglyceride concentration were slightly decreased by chitosan and chitosan oligomer supplement, especially in high fat groups. fat absorptivity was decreased by low fat level, chitisan and chitosan oligamer supplement. Fecal excretion of total lipid and triglyceride were increased by high fat level, chitosan and chi샌무 oligomer supplement. However, fecal excretion of total cholesterol was increased by high fat level and chitosan supplement. This indicated that chitosan and chitosan oligomer were effective in interfering with lipid and triglyceride absorption, In conclusion, chitosan oligomer at levels of 3% and 5% has more effective lipid, cholesterol and triglyceride lowering activity than chitosan.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.107-113
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• 1998

This study was performed to investigate the effects of chitin, chitosan and dithiocarbamate chitosan on the cadmium accumulation in liver and kidney of catfish. The experimental groups were divided into four independent groups which were one control group and three experimental groups by cadmium alone treatment or chitin, chitosan and dithiocarbamate chitosan which cadmium. in order to investigate the effects of chitin, chitosan and dithiocarbamate chitosan on the cadmium accumulation in liver and kidney of catfish, the cadmium concentration, the metallothionein level were measured. The results obtained were as follows: 1. The cadmium concentrations in liver and kidney of catfish in cadmium alone treatment group were similar to that of the chitin treatment group, but chitosan and dithiocarbamate chitosan treatment groups were significantly decreased. 2. The metallothionein levels in liver and kidney of catfish alone treatment group were similar to that of the chitin treatment group, but chitosan and dithiocarbamate chitosan treatment groups were significantly increased. In conclusion, this study revealed the effect of chitin, chitosan and dithiocarbamate chitosan against cadmium accumulation in liver and kidney of catfish. It exhibited the highest effect at dithiocarbamate chitosan treatment group.

• Journal of Life Science
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• v.9 no.1
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• pp.17-21
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• 1999

Chitosan derivitives, a sulfated N-acetylchitosan was synthesized, and artificial skin of sulfated N-acetylchitosan and N-carboxyl butyl chitosan were investigated. Sulfated derivatives of chitosan were analyzed by {TEX}${13}^C${/TEX}-NMR and the structure on N-acetyl chitosan 3,6-O-disulfate were confirmed. Rabbits underwent a midline laparotomy followed either by a bilateral peritoneal sidewall abraison(3.0×1.5cm). The injured surface was then covered with 0.2mm thick sulfated N-acetyl chitosan membrane. Sulfated N-acetyl chitosan membrane was found to reduce postsurgical bleeding after abraison of peritoneal surface treated with sulfated N-acetyl chitosan membrane. Sulfated N-acetyl chitosan implanted rabbit showed quick wound healing than N-carboxybutyl chitosan. With a sterilization procedure of chemical sterilization, sulfated N-acetyl chitosan seem to be better substitutes than N-carboxybutyl chitosan.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.21-34
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• 2006

To investigate anti-HIV-1 activity of water soluble chitosans, sulfated chitosan derivatives were prepared in mild condition. Various sulfated chitosan derivatives (N-3,6-O-S-chitosan, N-desulfated 3,6-O-S-chitosan, 3,6-O-S-chitin, and 3,6-O-sulfated-N-(o-carboxybenzoyl) chitosan) were synthesized with sulfurtrioxidepyridene complex in pyridine solvent. Characterization of the sulfated chitosan derivatives was carried out by $^{13}C$ NMR and IR spectroscopies. To observe ionic reaction properties, pKas of the sulfated chitosan derivatives and chitosan of low molecular weight were estimated by potentiometric titration. The sulfated chitosan derivatives had high water solubility, pKas (pKa : 7.7) of N-3,6-O-S-chitosan and N-desulfated 3,6-O-S-chitosan were increased than pKa of water insoluble chitosan (pKa : 6.2), These results suggest the participation of electrostatic interaction of amino and sulfate groups on the sulfated chitosans. Anti-HIV-1 drugs, such as AZT, ddC, and ddI for anti-HIV activity had higher selective index compared with SCB-chitosan but N-3,6-O-S-chitosan has shown higher selective index compared with ddC and ddI as HIV drugs.. These results suggest that sulfated chitosan derivatives were expected as an anti-HIV drug with differential driving force mechanism against some nucleoside analogs drug in the future.

• Culinary science and hospitality research
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• v.8 no.1
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• pp.43-54
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• 2002

In order to enhance the functional characteristics of the white pan bread, chitosan had been added into a wheat flour at the level of 1, 3, and 5%. The effect of the chitosan had been analyzed by experimenting the changes of volume Our ing dough fermentation, comparing the loaf volume and the specific volume, sensory evaluating the quality of the bread, and checking the retrogradations process. The results were as follows; 1. When the chitosan was added at the level of 1%, the result of the fermentation showed the highest. However, as the level of the chitosan increased, fermentation had been delayed. 2. The volume of the bread also showed the highest result when the chitosan was added at the concentrate of 1%. Similarly, as the level of the chitosan increased, the volume became smaller than others The specific volume also revealed the same consequent. 3. The sensory evaluation of white breads also showed the best result when the chitosan was added by 1%. 4. The retrogradations process of white pan breads could also be further delayed when the chitosan was added by 1%. Consequently, when the chitosan was added at the level of 1% into the wheat flour dough based on baker's%, not only the product quality of the white pan bread became the best, but also we could see the possibility of producing a functional bread using the chitosan.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.323-329
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• 2004

The electrical and rheological properties pertaining to the electrorheological (ER) behavior of chitosan derivatives, chitosan, chitosan ammonium salt and chitosan phosphate suspensions in silicone oil were investigated. Chitosan derivative suspensions showed a typical ER response (Bingham flow behavior) upon application of an electric field. However, chitosan phosphate suspension exhibited an excellent shear yield stress compared with chitosan and chitosan ammonium salt suspensions. The difference in behavior results from the difference in the conductivity of the disperse phases due to the difference of their polarizability. The shear stress for the chitosan, chitosan ammonium salt and chitosan phosphate suspensions exhibited a linear dependence on the volume fraction of particles and 1.18 ,1.41 and 1.67 powers of the electric field. On the basis of the experimental results, the newly synthesized chitosan derivative suspensions found to be an ER fluid.

• KSTLE International Journal
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• v.5 no.2
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• pp.49-51
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• 2004

The electrical and rheological properties pertaining to the electrorheological (ER) behavior of chitosan derivatives, chitosan, chitosan ammonium salt and chitosan phosphated suspensions in silicone oil were investigated. Chitosan derivative suspensions showed a typical ER response (Bingham flow behavior) upon application of an electric field. However, chitosan phosphate suspension exhibited an excellent shear yield stress compared with chitosan and chitosan ammonium salt suspensions. The difference in behavior results from the difference in the conductivity of the disperse phases due to the difference of their polarizability. The shear stress for the chitosan, chitosan ammonium salt and chitosan phosphate suspensions exhibited a linear dependence on the volume fraction of particles and 1.18, 1.41 and 1.67 powers of the electric field. On athe basis of the experimental results, the newly synthesized chitosan dervative suspensions found to be an ER fluid.

• The Korean Journal of Food And Nutrition
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• v.13 no.3
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• pp.242-248
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• 2000

수산물 가공시 흘러나오는 폐수 중에 함유되어 있는 수용성 단백질을 chitosan에 흡착시키기 위하여 albumin과 hemoglobin, albumin-myoglobin 혼합단백질을 이용하여 chitosan과의 흡착 및 chitosan 제조조건에 따른 흡착효과와 chitosan의 수용성 단백질 흡착에 미치는 인자를 살펴본 결과는 다음과 같다. Chitosan위 탈아세틸화 조건을 60, 70, 80%로 달리하여, albumin, hemoglobin, albumin-myoglobin 혼합용액에 적용했을때 chitosan의 탈아세틸화도가 높을수록 chitosan과 단백질 사이의 흡착률은 높게 나타났다. 초음파 처리에 의하여 chitosan의 분자량이 작을수록 chitosan과 단백질 사이의 흡착률은 높게 나타났다. pH변화에 따른 chitosan과 수용성 단백질의 흡착률은 albumin 및 albumin-myoglobin 혼합용액에서는 pH 4.0에서, hemoglobin용액에서는 pH 7.0에서 흡착률이 높게 나타났다 chitosan과 수용성단백질과의 흡착에서 반응시간은 albumin및 albumin-myoglobin 혼합용액에서는 4시간, hemoglobin용액에서는 3시간까지 흡착률이 증가하였고, 그 이후의 시간이 경화하여도 흡착률의 증가는 거의 보이지 않았다. 수용성 단백질 용액에 NaCl 농도를 0.1M에서 1.0M로 증가시켜 첨가했을때 염의 농도가 높을수록 chitosan과 단백질 사이의 흡착이 잘 일어나지 않았다.