• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.404-409
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• 1999

The studies were carried out to investigate antimicrobial activity of mixture of Caesalpina sappan L. and Lithospermum erythrorhizon extracts against lactic acid bacteria isolated from Kimchi. The effects of the mixture and crab shell extracts on the shelf-life of Kimchi were also investigated. The growth of heterofermentative lactic acid bacteria and homofermentative lactic acid bacteria was inhibited by 98% ethanol extracts of Caesalpina sappan L. and Lithospermum erythrorhizon. The pH of Kimchi containing mixed extracts of Caesalpina sappan L. and Lithospermum erythrorhizon extracts (1 : 1) and crab shell was lower than that of control during fermentation for 25 days of $10^{\circ}C$. The viable cells of Lactic acid bacteria of the mixed extracts and crab shell added Kimchi were lower than that of control during fermentation. The sensory quality of the mixed extracts and Crab shell added Kimchi was a little inferior to control for during fermentation of Kimchi.

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.55-63
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• 1999

The purpose of this study was to investigate the purification of chitin and chitosan for textile finishing agent from crab shell. Weight loss rate(removing Ca and protein), degree of deacetylation, solubility and MIC(Minimum growth inhibitory concentration) value of chitosan and molecular weight of the treated crab shell were measured. The results of this study were as follows : 1) Weight loss rate(removing Ca) of crab shell treated with HCI increased with the concentration of HCI and treatment time, but it became constant over 60 min. of treatment time. 2) Weight loss rate(removing protein) of crab shell treated with NaOH(0.5N∼2N) increased with the concentration of NaOH and treatment temperature and time, but it became constant above loot of temperature and over 200 min. of treatment time. 3) Degree of deacetylation of chitin treated with NaOH increased with the concentration of NaOH(40∼60％), but molecular weight decreased and thus MIC value increased. 4) Concentration of acetic acid should be above 0.3％ to dissolve chitosan easily. Solubility for chitosan was the highest with formic acid, and the next was acetic acid, hydrochloric acid, lactic acid and sulfuric acid in order.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.195-200
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• 2000

Chitin과 탈아세틸화된 chitosan은 중금속 제거에 효과적인 생물흡착제로 잘 알려져 있다. 그러나 본 연구의 결과 crab shell에 있어서의 중금속 제거효율이 순수 chitin과 chitosan에서 보다 더 뛰어남을 알 수가 있었다. 납, 카드뮴, 망간이온 제거실험에서 crab shell은 초기 2시간 이내에 모두 제거되었으나, chitin과 chitosan의 흡착 실험에선 14시간이 경과되어도 이들 중금속의 대부분 수용액 내에서 거의 제거되지 않았다. 구리의 경우 염의 형태에 따른 흡착의 영향을 chitosan에선 제거된 량이 Cu($SO_{4})_{2}$ > Cu($NO_{3})_{2}$ > Cu($Cl_{2}$)의 순으로 나타났으나 chitin에선 모두 흡착이 거의 안된 상태로 나타났다. 주사현미경 분석 결과 crab shell의 표면에 납이 축적되어 있는 상태를 확인하였다.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.185-190
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• 2005

An experiment was conducted to know the effects of crab shell, sericite ore, and charcoal powders on the growth, yield, and grain quality of rice. After application of 110-40-57 kg/ha of $N-P_2O_5-K_2O$, 3,000 kg/ha of crab shell and charcoal powders and 5,000 kg/ha of sericite ore powder were applied and incorporated into soil before transplanting of rice seedlings. The number of tillers and panicles, leaf area index at heading stage, N concentration of plants, and protein content and chalkiness of rice grains were increased with the application of crab shell powder, while the percentage of ripened stains and head rice and Toyo taste value were decreased. The yield of milled rice and other grain appearance and chemical and physical properties of rice grains were not affected by the application of crab shell powder. The sericite ore and charcoal powders increased protein content decreased Toyo taste value, but did not affect on the growth, yield and yield components and other grain qualities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.105-113
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• 1995

Procedures for isolatin of chitin have been developed from crab(Chionoecetes opilio) shell waste with 26. 65% chitin on a dry basis. Optimal conditions for demineralization of crab shell were 1N HCl at ambient temperature for 30min with a solids to solbent ratio of 1 : 15(w/v). Optimal deproteinization involved treatment with 5% NaOH at $65^{\circ}C$ for 1 hr with a solids to solvent ratio of 1 : 15(w/v). Effective decoloration was achieved by bleaching with 0.32% sodium hypochlorite solution for 3min with a solids to solvent ratio of 1 : 10(w/v). Particular attentin was given to characterization of the physicochemical properties of the crab chitin. Chitins, from four different mesh sizes of crab shell, did not show significant differences in nitrogen and ash compositions. Bleaching decreased the viscosity of chitin but did not affect its solubility.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.36-43
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• 2001

Chitosans were prepared from red crab chitin under various alkali treatment conditions(different alkali concentrations, reaction times and temperatures) and theirphysicochemical properties were investigated. The nitrogen content and deacetylation degree of red crab chitin were 6.15% and 22.17A%, respectively. By the IR spectra, red crab and reference chitin showed the sharp bands at 1650 $cm^{-1}$ / and 1550 $cm^{-1}$ /, which are characteristic of chitin. The nitrogen contents of prepared chitosans ranged from 6.19~7.48%. Thedeacetylation degree was increased from 63~76% and 48~78% with increasing reaction time and temperature, whereas viscosity was decreased. The nitrogen content and yield of red crab chitosan perpared from chitin with 50% NaOH, 1:25(w/v) for 3.0 hr at 120$cm^{-1}$ / were 7.26% and 85.0%, respectively. and viscosity, deacetylation degree and molecular weight, 67.0 mPa.s, 75.0% and 6.5$\times$10$^{5}$ Dalton, respectively. From the IR spectra, the amide absorption bands of red crab and reference chitosan became very weak, similarly. And at solid state $^{13}$ C-NMR spectra, C=O(carbonyl carbon) signals absent, whereas $CH_3$(methyl carbon) was residues. Chemical shift of $^{13}$ C-NMR spectra of red crab and reference chitosans were in good agreement with slight experimental deviation.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.115-126
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• 1998

In use of anaerobic bioconversion shellfish wastes present special problems, since the chitinous structures in the shell faction degrade very slowly in an anaerobic environment. Enzymatic pretreatment method was evaluated for improving the anaerobic bioconversion potential of blue crab processing wastes. An enzymatic pretreatment using chitinase enhanced the ultimate methane yield and biodergradation rate constant for total crab solid wastes by 15% and 19% respectively, above those of the untreated wastes. When the enzymatic pretreatment applied to the shell fraction alone, it resulted in increase of 34% in the ultimate methane yield and 38% in the reaction rate. The results indicate that anaerobic bioconversion of these wastes is technically feasible and enzymatic pretreatment will improve the efficiency of the process.

• Journal of the Korean Society of Food Culture
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• v.23 no.6
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• pp.667-680
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• 2008

The moisture contained in conventionally extracted red crab shell samples was lower than than in samples extracted using high pressure. In contrast, ash content increased as the extraction time increased and displayed no significant variation in high pressure extraction. Extraction time was influential, with lower lightness (L-value) being obtained in samples extracted at high pressure as compared to traditional extraction. However, large variation in a- and b-values resulted from traditional extraction. For both traditional and high pressure extraction increases in pH, salinity and saccharide content were noted with increasing extraction time, but these parameters did not vary substantially in red crab shell extracted at high pressure. The mineral content in samples extracted by high pressure was higher than in traditionally extracted samples. The mineral content increased with time, with marginally higher contents of essential amino acids and flavor enhancing amino acids noted following high pressure extraction. The contents of the flavor enhancing amino acids increased from 30?60 min, thereafter decreasing. Assessment of consumer acceptance revealed that, while traditionally manufactured red crab sauce was popular, sauce manufactured using a 60 min high pressure extraction was preferred. Extending the high pressure extraction time to 75 min produced a less sensory acceptable product, due to higher mineral and protein levels.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.729-735
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• 2002

In order to examine the inhibition effect of other heavy metal ions on the removal of heavy metal ions by crab shell in aqueous solution, 10 heavy metal ions $(Cr^{3+},\;Cd^{2+},\;Ni^{2+},\;Zn^{2+},\;Hg^{2+},\;Cu^{2+},\;Mn^{2+],\;Fe^{2+},\;Fe^{3+},\;Pb^{2+})$ were used as single heavy metal ions and mixed heavy metal ions, respectively. In single heavy metal ions, $Pb^{2+},\;Cr^{3+},\;Cu^{2+}$ were well removed by crab shell, however, $Cd^{2+},\;Ni^{2+},\;Zn^{2+},\;Mn^{2+}$ were not. The heavy metal removal increased as the increase of covalent index (Xm$^2$r), and the relationship classified heavy metal ions as 2 heavy metal groups $(Fe^{3+},\;Fe^{2+},\;Cu^{2+},\; Cr^{3+},\;Mn^{2+},\;Ni^{2+},\;Zn^{2+}\;group\;and\;Pb^{2+},\;Hg^{2+},\;Cd^{2+}\;group)$. In mixed heavy metal ions, the removals of $Fe^{2+},\;Fe^{3+},\;Pb^{2+},\;Cu^{2+}$ as 0.49 m㏖/g, regardless of the existence of other heavy metal ions, were similar to the result of single heavy metal ions experiment. The removals of $Mn^{2+},\;Cd^{2+},\;Ni^{2+}$ decreased as the existence of other heavy metal ions, however, the removal of $Zn^{2+},\;Cr^{3+},\;Hg^{2+}$ increased.

• The Korean Journal of Mycology
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• v.36 no.1
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• pp.22-25
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• 2008

Pleurotus eryngii is by far the best tasting oyster mushroom, well deserving of the title, the King Oyster. Popular in Europe, this stout, thickly fleshed mushroom, is one of the largest species in the genus. The effects of addition of crab shell to sawdust substrate for the growth of P. eryngii were investigated. Dried crab shell used in this study contained 55.2% C, 3.74% N, 5.57% $P_2O_5$, 6.44% Ca, and pH 6.9. The addition of 1% crab shell (v/v) increased the yield of the mushroom fruit-body by 34% comparing control (sawdust 80, rice bran 20; v/v), 0.03% CaO content of 1% crab shell treatment was higher than 0.01% CaO of control and period of primordia formation was similar regardless of the treatments.