• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.14-24
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• 1992

An attempt was made to prepare chitin from kuruma prawn shell and antarctic krill for industrial use, and new procedure for the preparation of chitin was developed. When antarctic krill powder and kuruma prawn shell powder were treated through the new procedures developed in this study, purified chitin, identified by IR spectrum and nitrogen content, was obtained. Molecular weight in formic acid of purified chitin was $1.56{\times}10^{5}$ for krill and $1.78{\times}10^{5}$ for kuruma prawn respectively. Degree of polymerization of N-acetylglucosamine was 750 for krill chitin and 850 for kuruma prawn chitin. Purified chitin showed a higher degree of acetylation, and was relatively rich in methionine residue.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.309-313
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• 2000

For the use of Antartic krill(Euphausia superba Dana) as food resource, general composition, extracting condition of chitin and quality characteristics of chitosan were investigated. General composition of frozen krill(Euphausia superba Dana) was consisted of moisture 79.0%, protein 13.1%, lipid 4.0%, VBN 7.7mg%, ash 2.7%, others 1.2% and that of dried krill powder was moisture 5.6%, protein 56.1%, lipid 18.8%, ash 11.4%, others 8.1%. The condition of chitin extraction from krill powder was treated with 1N NaOH at $40^{\circ}C$ for removing protein, 1N HCl for excepting mineral substances and methanol for decoloring. The yield of chitin by new procedure developed was 3.7%. The composition of extracted chitin contents was moisture 7.1%, ash 0.4%, protein 3.5%, lipid 3.1%. The results of degree of deacetylation in chitosan at 50% NaOH, $121^{\circ}C$, for 2 hrs was showed 82%. At the same alkali concentration and reaction concentration, a longer reaction time gave a decreased degree of deacetylation. The apparant viscosity was 0.09241 Pa in 1% chitosan from krill and 0.13826 Pa in standard chitosan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.45-50
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• 1992

To utilize shellfish by-products effectively, chitin, chitosan, and microcrystalline chitin were prepared from 6 kinds of crustacean shells(Antarctic krill, Euphausia superba; Red snow crab, Chinonecetes japonicus: Daelongsuyum shrimp, Solenocera prominentis: Lobster, Linuparus trigonus: Gasibal shrimp, Nephrops thomsoni: Blue crab, Portunus trituberculatus) and their functional properties were studied. Apparent volume(AV), settling volume(SV), water binding capacity(WBC), and fat binding capacity(FBC) of various chitins, chitosans, and microcrystalline chitins ranged from $3.1\pm0.1ml/g\;to\;27.0\pm0.2ml/g$ from $5.1\pm0.1ml/g\;to\;45.0\pm0.2ml/g,\;from\;318\pm40g/100g\;to\;2,382\pm12g/100g,\;and\;from\;235\pm20g/100g\;to\;2,169\pm20g/100g$, respectively, and the krill chitin and chitosan had the highest AV, SV, WBC, and FBC of them. Chitins and chitosans did not produce emulsion but microcrystalline chitins showed emulsifying properties. Emulsifying capacity and stability of various microcrystalline chitins ranged from $18.2\pm4.0\%\;to\;50.1\pm2.5\%\;and\;from\;15.2\pm3.5\%\;to\;31.1\pm1.0\%$, respectively. Dye binding capacity of microcrystalline chitins was higher than that of chitins or chitosans.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.1
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• pp.40-50
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• 1990

The purpose of this paper is to develop a colorant from krill, Euphausia superba, process wastes for use in food products. Carotenoproteins were extracted from preboiled krill processing offal(PKPO) and raw frozen krill processing offal(RKPO) with the aid of proteolytic enzymes. The long-term stability of the astaxanthin associated with the carotenoprotein by the addition of pretense inhibitor and antioxidant to the product were also investigated. Total astaxanthin contents of PKPO and RKPO were $35.1mg\%,\;22.1mg\%$ and those in carotenoproteins were $98.6mg\%,\;61.9mg\%$, respectively. The chitin contents of PKPO and RKPO were $6.9\%,\;4.5\%$, however, those of carotenoproteins were not determined. When $0.5\%$ trypsin was added to the extraction medium containing 0.5M $Na_3EDTA$ at $4^{\circ}C,\;74\%$ of astaxanthin and $83\%$ of the protein of PKPO were recovered as carotenoprotein in 24hrs. The amino acid profile in carotenoprotein was mainly composed of glutamic acid, methionine, aspartic acid and isoleurine. Their contents amounted to about 40% of the total amino acids, followed by alanine, phenylalanine, Iysine, leucine, threonine and tyrosine in that order, with a small amount of cysteine and tryptophan. The levels of essential amino acids were high as much as $38.3\%\~43.6\%$ of the total amino acids. The maximum observance of the carotenoid fraction from krill processing offal and from carotenoprotein was 469nm in petroleum ether. The separated components of carotenoprotein by TLC had Rfs $0.20\~0.23\;0.56\~0.60$ and $0.88\~0.91$. The carotenoids were comprised of astaxanthin, astaxanthin monoester and asthaxanthin diester in $25\~30\%\;,35\~40\%$and $40\~45\%$, respectively. The loss of carotenoids in the carotenoprotein can be prevented by the addition of pro-tease inhibitor(trasylol) and antioxidant(BHT) below $4^{\circ}C$.