• 한국식품과학회지
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• 제26권4호
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• pp.348-354
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• 1994

반응 조건을 달리하여 게껍질에서 chitin을 추출하고 이를 탈아세틸화하여 chitosan을 제조하였으며, 이들의 물리, 화학적 특성과 소화관내 기능성을 in vitro법으로 실시하였다. 이들 chitin질의 bulk density는 $127{\sim}208\;mg/ml$, 점도는 0.1% chitin의 경우 $80{\sim}581\;cP$, 0.5%, chitosan은 $80{\sim}3,670\;cP$로 다양한 수치를 나타냈으며, chitosan의 탈아세틸화도는 $81{\sim}93%$로 비교적 높았다. Chitosan 제조시의 알칼리 농도와 반응 온도가 일정할 때 반응 시간이 경과할수록 탈아세틸화도는 증가하였고, 점도는 감소하는 경향을 보였다. Chitin질의 보수력은 온도 상승에 따라 약간 상승하였고, $37^{\circ}C$에서 chitosan D가 가장 높았으며, bulk density가 낮을수록 높은 보수력을 나타냈다. Glucose 흡수 억제 효과는 bulk density가 낮고 보수력이 큰 chitin길이 더 컸고 chitosan D가 가장 높은 38%를 나타냈다. Chitin질의 bile acid 흡수 억제 효과는 투석 1시간 후에 $15{\sim}34%$를 나타냈고, pectin은 39%, cellulose는 9%를 나타냈으며 chitosan D는 3% 농도에서 34%의 가장 높은 억제 효과를 나타냈다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.18-24
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• 2001

The advantage of using Streptomyces griseus HUT 6037 in the production of chitinase or chitosanase is that the organism is capable of hydrolyzing amorphous or crystalline chitin and chitosan according to the type of the substrate used. We investigated the effects of the enzyme induction time and chitin sources, CM-chitosan and deacetylated chitosan (degree of deacetylation 75-99%), on production of chitosanase. We found that this strain accumulated chitosanase when cells were grown in the culture medium containing chitosanaceous substrates instead of chitinaceous substrates. The highest chitosanase activity was obtained at 4 dyas of cultivation with 99% deacetylated chitosan. The specific activities of chitinase and chitosanase were 0.91 and 1.33 U/mg protein at 3 and 5 days, respectively. From the study of the enzymatic digestibility of various degrees of deacetylated chitosan, it was found that (GlcN)$_3$, (GlcN)$_4$and (GlcN)(sub)5 were produced during the enzymatic hydrolysis reaction. The results of this study suggested that the sugar composition of (GlcN)$_3$was homogeneous and those of (GlcN)$_4$and (GlcN)(sub)5 were heterogeneous.

• 한국의류산업학회지
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• 제5권1호
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• pp.64-70
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• 2003

Water-insoluble chitosan with molecular weight of 2,000,000, 580,000, 80,000, and 40,000 and more than 90% of degree of deacetylation were prepared to test antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus (MRSA). As experimental method, the Shake Flask Method (SFM) and Modified Shake Flask Method (MSFM) were applicated. The anti-microbial activity of chitosan/acetic acid aqueous solution is consistent irrespective of Mw of chitosan. MIC value of SFM measurement was 0.2 ppm, and MIC value of modified SFM measurement was 25 ppm. But MIC value of chitosan/acetic add solution and chitosan treated cotton filter paper was equally 5 ppm. The antibacterial activities of chitosan were different in different test measurements employed. The antibacterial activities of chitosan/acetic acid solution and chitosan treated cotton filter paper were also different. Therefore, it needs to be pointed out that the test measurements of anti-microbial activity have some problems.

• 복식문화연구
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• 제12권6호
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• pp.999-1009
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• 2004

Chitin is a derived product from the shell of shrimp or crab. Chitosan, a deacetylated product of chitin, has widely been used in the biomedical sector, food industry, and textile industry. Chitosan exhibits fiber-forming property under certain conditions. Nonwoven fabrics made of chitosan fibers may have diverse applications in the industry. Previous studies have revealed that the dye uptake properties of natural dyestuffs improved by the chitosan pretreatment on the fabric specimens. In this case, fabric specimen is coated with acidic salt form of chitosan, which is different from the pure chitosan, since the coating process employes coating with the acidic solution of the chitosan and subesquent drying. In this study, chitosan nonwoven fabric samples were prepared from chitosan sample having deacetylation degree of $100\%$ and molecular weight of 650,000. Chitosan nonwoven fabrics maintain the form of $-NH_2$ end-group. These in turn exhibit higher dye uptake ability than the fabrics coated with chitosan acidic solutions do.

• 한국식품과학회지
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• 제27권1호
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• pp.6-10
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• 1995

대롱새우껍질로부터 Neutrase처리로 단백질을 제거하고 0.1 M EDTA 2Na로 무기질을 제거하여 키틴을 분리 정제하였다. 키틴의 정제시 Neutrase 3 mg/ml을 첨가하여 pH 6.0, $50^{\circ}C$에서 처리하였을 때 단백질 제거 효과가 제일 좋았다. Neutrase처리에 의한 단백질 제거, 탈 아세틸화도 그리고 칼슘, 인함량은 시판 키틴과 거의 비슷하였다. 분자량은 $1.2{\times}10^{8}$ dalton이었고 키틴의 수율은 28.5%이었다.

• 환경위생공학
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• 제14권2호
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• pp.46-55
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• 1999

This study compared the adsorption characteristics of heavy metal ions by crab shell, treated crab shell with 2N-HCl, treated crab shell with 4%-NaOH, chitin and chitosan.Using crushed crab shell, the heavy metal ions removal rates of $Cd^{2+}$ and $Zn^{2+}$ were about 70-80% in 45minutes, but the removal rates of $Cu^{2+}$, $Cr^{6+}$ and $Pb^{2+}$ was less than 10%, 10% and 30%, respectively. For the by-products crab shell by 2N-HCl treatment, it was shown that the removal rates of $Cu^{2+}$ and $Pb^{2+}$ were about 70-80% in 45minutes reaction. But, some problems were observed, that the contained protein in crab shell was changed into gel in the mixing solution after a few hours. For the by-products of crab shell by 4%-NaOH treatment, the removal rates of Pb and Zn were about 90% in 45 minutes, and those of capacity of chitin and chitosan powder was better than those of the other by-products. The more adding to the adsorbent dosages increased the removal rates, and the adsorption reaction was rapidly occurred in a few minute. Using 1.0 wt% chitin powder, the heavy metal removal rates were ordered $Cu^{2+}$(94%) > $Zn^{2+}$(89%) > $Cd^{2+}$(88%) > $Pb^{2+}$(77%) > $Cr^{6+}$(58%) in 45 minutes. Using 1.0 wt% chitosan powder, the heavy metal removal rates were ordered $Cu^{2+}$(99%) > $Pb^{2+}$(96%) > $Cd^{2+}$(79%) > $Zn^{2+}$(71%) > $Cr${6+}$(46%) in 45minutes. The degree of degree of deacetylation by prepared chitosan was 91%.The Freundlich adsorption isotherm of $Cu^{2+}$, $Cd^{2+}$ and $Zn^{2+}$, when it was applied to 1.0 wt% chitosan powder in minutes, can be acceptable very strictly. The equation constant (1/n) for $Cu^{2+}$, $Cd^{2+}$ and $Zn^{2+}$ were 0.54 0.41 and 0.23 respectively.

• 한국잠사곤충학회지
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• 제40권2호
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• pp.158-162
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• 1998

The chitin was isolated from various kinds of insects such as exuvia of Psacothea hilaris Pascoe, silkworm pupa, Agrius convolvuli or from cuticle of cockroach by treatment with dilute HCI and NaOH. The chemical and crystalline structure was characterized by FT-IR and X-ray diffractometer. All of the chitins extracted from insects showed characteristic ${\alpha}$-chitin peaks at the Bragg angle 2$\theta$=9.3$^{\circ}$, 19.4$^{\circ}$, and 23.5$^{\circ}$by X-ray diffraction analysis. The transition from chitin to chitosan was confirmed by IR spectra and the degree of deacetylation of the crab shell, silkworm pupa, cockroach, and Psacothea hilaris Pascoe was 70.9, 76.4, 75.5, and 74.1%, respectively. The double diffraction peaks of insect chitosan were observed at 2$\theta$=10$^{\circ}$and 20$^{\circ}$, indication the characteristic of hydrated crystalline structure of chitosan.

• 한국수산과학회지
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• 제28권4호
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• pp.397-400
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• 1995

Chitosan 용액의 물성학적 특성을 조사하기 위하여 chitosan 용액의 점도에 미치는 전단속도, 온도, 농도 및 염의 영향을 조사한 결과, chitosan 용액$(0.5\%)$의 유동곡선은 hysteresis loop가 나타나는 Bingham 유체와 일치하였고, $10^{\circ}C-40^{\circ}C$에서 Arrhenius 온도의존성을 나타내었다$(2\%,\;2.5\%,\;3\%\;chitosan$ 용액). 활성화 에너지는 3.25-8.35(kcal/g mol)로 전단속도가 높을수록 그리고 농도가 높을수록 증가하였다. Chitosan 용액의 겉보기점도는 농도가 증가할수록 지수적으로 증가하였고, 측정 온도가 높을수록 농도의존성은 낮았다. 한편 chitosan용액에 염을 첨가하였을 때 점도감소현상이 나타났으며, 염농도가 높아짐에 따라 점도의 감소폭은 줄어들었다 염의 종류에 따른 점도변화는 없었다

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권1호
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• pp.9-14
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• 2001

With the object of providing a temporary artificial periodonal ligament-like membrane around the dental implant, 10 Branemark type implants were coated with commercially available chitosan(Fluka Co., Buchs, Switzerland) which has a molecular weight of 70,000 and 80% deacetylation degree. Once this bioactive hydrophillic polymer(chitosan) contacts with blood or wound fluids, it becomes swollen and penetrates into the adjacent cancellous bone. Thus the interface between implant and surrounding bone is completely filled with chitosan. This tight junction in early healing phase enhances primary stability. The chitosan coated dental implants were implanted into the fresh patella bones from porcine knees, since the thickness of cortical bone is relatively even and their cancellous structure is homogenous. To test the shock absorbing effect, 1mm delta-rogette strain gage was installed behind the implant. The results showed 1. The principal strain peak value directed to the impact of coated implant was 0.064 0.018(p<0.05) and that of uncoated implant was 0.095(0.032 p<0.05). 2. The peak time delay of coated implant was 0.056sec(0.011 p<0.05) and that of uncoated implant was 0.024sec(0.009 p<0.05). It can be reasoned from this results that the chitosan coating has a shock absorbing effect comparable with a temporary artificial periodontal ligament.

• 한국식품과학회지
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• 제28권5호
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• pp.870-876
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• 1996

가시발새우 껍질을 부가가치가 높은 자원으로 활용하기 위하여, 이들로부터 키틴과 키토산을 제조하여 물리화학적 특성을 살펴 보았다. 가시발새우 껍질에서 추출한 키틴의 일반성분은 질소 6.84%, 지방 0.57%, 회분 0.32%였으며, 수율은 15.7%였다. 키토산은 질소함량이 7.52%였으며 지방과 회분함량은 각각 0.13%와 0.33%였다. 그리고 탈아세틸화도는 67.5%, 분자량은 $9.1{\times}10^5$이었으며 수율은 75%를 나타내었다. 키틴 및 키토산의 잔류 아미노산은 각각 2.64mg/g과 1.39mg/g 검출되었고, 그 중 lysine이 가장 높게 나타났다. 한편 키틴과 키토산의 IR 스펙트럼과 고체상태 $^{13}C-NMR$ 스펙트럼 data는 분자구조를 확인하는데 도움이 되었다.