• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.317-323
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides against three Gram-negative bacteria and five Gram-positive bacteria. Nine classes of hetero-chitosan oligosaccharides consisted of partially deacetylated chitosans; 90％, 75％, and 50％ deacetylated chitosans. Based on molecular weight, they were prepared using an ultrafiltration membrane reactor system. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity as compared with the 90％ and 50％ deacetylated chitosan, and the activity was dependent on their molecular weights. It was apparent that the growth of Gram-negative bacteria is less inhibited in the presence of the heterochitosans and their oligosaccharides than Gram-positive bacteria. These results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides depend on the degree of deacetylation, and their molecular weights.

• 한국의류학회지
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• 제28권6호
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• pp.807-818
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• 2004

The antibacterial activities of several types of chitosan were measured against Staphylococcus aureus and evaluated for their application to antibacterial textile finishing. The ％ reduction of bacteria of the chitosans prepared in our laboratory were between 72 and 87%. The two water-soluble chitosans with molecular weights 1,000 and 3,000 did not show antibacterial activities. The deacetylation of chitosan was appeared to increase antibacterial activity. The ％ reduction in bacterial density of the 86％-deacetylated chitosan solution was 56% where that of the 76％-deacetylated chitosan solution was only 17％ at 0.1% chitosan concentration. Molecular weights of the chitosans seemed not to affect antibacterial activities of chitosans. The antibacterial activity of the acid-soluble, 86%-deacetylated chitosan with 4 cps showed 98% of the ％ reduction at the level of 0.2％ chitosan. The ％ reduction of bacteria of this chitosan was higher at the higher concentration of acetic acid in the chitosan-bacterial mixture. The antibacterial activity was increased with the pH change over the range of 4.0 to 6.5. The 100% of the ％ reduction of bacteria was achieved within 4 hour incubation of the chitosan-bacterial mixture. According to the data obtained from the above experiments, the four chitosans among the six prepared in our laboratory were proved to be valuable for antibacterial textile finishing.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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• pp.236-238
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• 2004

Functional porperties such as CL, VP and EM did not affected by the addition of chitosans, however, level and MW of chitosans affected textural properties of LFSs, resulting in harder and springer texture of LFSs containing 0.3% MME chitosan as compared to others, Approximately 9 flavor compounds were different between RFC and LFS, and the addition of chitosans did not affected volatile compounds in the LFSs.

• 한국축산식품학회지
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• 제29권1호
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• pp.75-81
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• 2009

Product quality and shelf-life effect of sodium lactate (SL) in combined with chitosans with various molecular weights (MW) in low-fat sausages (LFSs) stored at $10^{\circ}C$ were evaluated. LFSs with SL and chitosans had 75-76% moisture, 1-2% fat, and 15.8-17.1% protein with a pH range of 6.3-6.6. Water holding capacity was decreased, but most textural properties were increased with the addition of chitosan with MW of 30-40 kDa. Hunter a (redness) values were also increased with the addition of sodium lactate and chitosans in combination with laccaic acid at the level of 0.05%, resulting in similar Hunter a value of 150 ppm of sodium nitrite. The combination of SL and chitosans slightly extended the shelf-life of LFSs approximately 3-6 days at $10^{\circ}C$, resulting in inhibition the growth of L. monocytogenes and E. coli O157:H7, as compared to the control. However, the inhibition of microbial growth at $10^{\circ}C$ was not as strong as that at $4^{\circ}C$. Thus, the storage temperature should be as low ($<4^{\circ}C$) as possible to have a maximum antimicrobial activity in LFS containing SL and various chitosans.

• 대한화장품학회지
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• 제24권3호
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• pp.89-95
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• 1998

The aim of this study is to elucidate the anti-microbial activity and anti-oxidative activity of water-soluble chitosan with a molecular weight of 5,000-200,000. Water-soluble chitosans have demonstrated a regular anti-microbial activity on the tested strians by the paper disk method. In the MIC (Minimum Inhibitory Concentration) test, CC-01 (MW=5,000) with the lower MW showed the higher MIC value than the higher MW chitosan. The MW of chitosan increase, the MIC decreases. MICs of 4 chitosans(CC-02∼CC-05) against S. aureusTCC 65389, E coli ATCC 8739, p. aeruginosa, ATCC 9027 and C. albicans ,ATCC 10231 were 7.0-39.O$\mu\textrm{m}$, whereas MICs of chitosans against A. niger were over 2.OmM. Formula containing chitosan showed higher anti-microbial activities than the formula made with the chemical preservatives(Methylparaben 0.2％ and Imidazolidinyl Urea 0.3％). Among 5 water-soluble chitosans, CC-03(MW=92,163) showed the most potent anti-oxidative activity (IC$\sub$50/ : 0.2mM). In conclusion, the water-soluble low molecular weight chitosan could be served as natural preservatives and antioxidant in cosmetics.

• 한국해양바이오학회지
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• 제1권4호
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• pp.282-291
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• 2006

물에 용해한 수용성 ${\alpha}$-chitosan (1, 8, 22, 43, 67, 616 kDa)과 ${\alpha}$-chitosan (282, 440, 746, 1,110, 2,025 kDa) 및 ${\beta}$-chitosan (577 kDa)의 chitosan-ascorbate(CA)를 막걸리에 chitosan량으로 0.002% 농도로 첨가하여 $25^{\circ}C$에 저장하면서 pH, 산도, 효모수, 세균수, 당도 및 알코올농도 변화를 조사하여 보존성을 평가하였다. 막걸리에 CA를 0.001, 0.002 및 0.003% 농도로 첨가한 결과 0.003% 이상에서는 떫은맛이 강하여 본 실험에서는 0.002% 농도로 첨가하였다. 그 결과, chitosan 무처리 막걸리는 저장 6일째에 pH 및 산도가 각각 3.9~4.3 및 0.4~0.7%의 범위로 나타났으며 후 발효가 지속적으로 진행되었다. 6일째 이후는 산의 생성과 alcohol 농도가 급격하게 감소하였으며, 초산발효가 병행되었고 막걸리 용기표면에 외관적으로 볼 수 있는 미생물이 번식하였다. 대부분의 수용성 및 산가용성 ${\alpha}$-chitosan은 대조구와 뚜렷한 차이를 보이지 않았으나 22 kDa의 ${\alpha}$-chitosan과 440 kDa의 ${\alpha}$-chitosan-ascorbate는 저장 18일째까지 pH는 각각 3.80~4.20 및 3.60~4.31의 범위였으며 산도는 0.4~0.6% 및 0.4~0.7% 범위로 타 처리구에 비하여 변화의 폭이 낮았다. 또한 효모수와 세균수가 상대적으로 낮을 뿐만 아니라 알코올농도의 감소율도 낮았으며 용기표면에 번식하는 미생물이 발생되지 않았고 관능검사결과 가식기간이 약 일주간 연장되었다.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.41-47
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides on the halophilic bacterium, Vibrio parahaemolyticus. Nine classes of hetero-chitosan oligosaccharides were prepared based on their molecular weights, using an ultrafiltration membrane reactor system with chitosanase and celluase, from partially different deacetylated chitosans, 90%, 75%, and 50% deacetylated chitosan, respectively. Thirty-two strains of V. parahaemolyticus were isolated from various marine organisms such as shellfish, shrimps, octopus, and seabirds. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity. The minimal inhibitory concentration (MIC) was 0.5 mg/ml on 14 strains of V. parahaemolyticus, and MIC of the rest strains (18 strains) was 1.0 mg/ml. In addition, MIC of most hetero-chitosan oligosaccharides was 8.0 mg/ml. The results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides against V. parahaemolyticus depend on the degree of deacetylation, their molecular weights, and strains tested.

• Food Science and Biotechnology
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• 제14권3호
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• pp.433-436
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• 2005

Chitosans were obtained with varying deacetylation times using the ${\beta}$-chitin isolated from Todarodes pacificus, and their deacetylation degrees and average molecular weights were determined. Films prepared with the squid chitosans were characterized by estimating their tensile strengths, percent elongations, water vapor permeabilities, degree of swelling, and temperatures of glass transition and thermal decomposition. The results suggest that the squid chitosan films were comparable to common crustacean chitosan films in regard of mechanical, moisture barrier, and thermal properties, although further, multilateral investigations are necessary to make a more definitive conclusion.

• 한국축산식품학회지
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• 제25권3호
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• pp.285-294
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• 2005

본 연구는 기능성 육제품 개발로 키토산이 육제품 내에서 어떠한 조직적인 특성을 나타내는지 알아보기 위해 저지방 소시지에 키토산을 첨가한 기능성 소시지를 제조하여 향미를 분석하였고 저장기간에 따른 이화학적 특성의 변화를 조사하였다. 돈육 후지로부터 추출한 염용성 단백질에 키토산을 첨가하여 pH와 점도를 측정한 결과 중분자 키토산 처리구의 pH는 대조구에 비해 첨가량이 증가할수록 증가하는 경향이며, 점도는 이와는 반대로 저분자 키토산 처리구는 첨가량에 따라 차이를 보이지 않았으나(p>0.05) 중분자 및 고분자의 경우 첨가량이 증가할수록 점도 값이 증가하는 경향을 나타냈다(p<0.05). 대조구와 유의적 차이를 보인 처리구는 중분자 그리고 고분자 키토산을 $0.6\%$ 첨가한 처리구로 특정 분자량의 키토산이 일정수준 첨가되면 점성이 증가되는 것을 알 수 있었다. 이는 조직감 검사에서도 볼 수 있듯이 중분자와 고분자 키토산을 첨가한 소시지가 저지방 대조구에 비해 대부분의 조직감에서 높은 값을 나타내었다. 가열 전 반죽의 pH, 가열 후 소시지의 pH, 가열 감량, 진공 감량 그리고 보수력에서는 저지방 대조구와 비교해서 키토산 첨가 효과는 나타나지 않았다. 향미 성분 분석 결과 저지방과 고지방의 경우 차이를 보일 뿐 대조구와 비교하여 키토산 첨가에 따른 향미의 효과는 없었으며 저분자 키토산을 $0.6\%$ 첨가한 처리구가 유화형 대조구와 유사한 향미 특성을 나타내는 것을 알 수 있었다.

• Animal cells and systems
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• 제1권2호
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• pp.337-340
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• 1997

The purpose of this study is to evaluate whether water soluble chitosan, a natural nontoxic chelator, can reduce fetal contamination of radiostrontium in pregnant mice. Various forms of water soluble chitosans (10% or 1% powder, or 1% solution) were given to pregnant mice before or after contamination of 0.005 uCi/B.W(g) Sr-85. Transplacental transfer of Sr-85 to fetus was $6.8{\pm}2.7%$ of injected dose, when Sr-85 was administered at the 20th day of pregnancy. Fetal radioactivity was significantly reduced when mother mice were treated with water soluble chitosan before contamination of Sr-85. Water soluble chitosans of 10% or 1% powder, or 1% solution significantly reduced fetal retention of Sr-85 to $2.3{\pm}0.7%$, $2.7{\pm}0.8%$, and $2.0{\pm}0.9%$, respectively. However, fetal contamination was not reduced, when water soluble chitosans of 10% or 1% powder, or 1% solution were administered after maternal contamination of Sr-85. From these data we can conclude that water soluble chitosan could reduce fetal contamination of radiostrontium in pregnant mice, when given before the pregnant mice were exposed to radiostrontium.