• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.189-195
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• 1978

Using the skins of conger eel, Astroconger myriaster, and hagfish, Eptatretus burzeri, from fillet manufactory, the optimum conditions of skin glue processing were investigated and physical ana chemical properties of the product were also determined. The yields of conger eel and hagfish skin to the total body weight were $10.6\%$ and $11.4\%$, respectively. The optimum processing conditions for conger eel skin glue were the extraction of skins which were previously tinted with $0.3\%$ calcium hydroxide solution for one hour, in water at pH 5.5 and $60^{\circ}C$ for four hours. The additional water was six times sample weight. In case of the hagfish skin glue, the liming time with $0.3\%$ calcium hydroxide solution was suitable for three hours, and the skins were extracted with water as much as nine times sample weight at pH 5.0 and $60^{\circ}C$ for three hours. The contents of crude protein of conger eel and hagfish skin glue were $91.5\%$ and $90.2\%$, respectively. The content of crude lipid was slightly higher than that of chemical grade gelatin. Relative viscosity, melting point, gelation temperature and jelly strength of conger eel skin glue were 13.6, $15.2^{\circ}C$, $6.2^{\circ}C$ and 13.0g respectively and those of hagfish skin glue were 12.9, $14.8^{\circ}C$, $4.3^{\circ}C$ and 23.3g respectively. The turbidity of conger eel skin glue and hagfish skin glue were slightly superior to those of dry glue.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.1-9
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• 1977

The purpose of this study is to complish a method of fish glue malting with residual products such as fish head and skin discarded from sea food processing. Using the skins of Alaska pollack and file fish from fillet packers, the optimum conditions of skin glue processing were investigated and physical and chemical properties of the product were also determined. The yields of Alaska pollack, Thelagra calcogramma, skin and file fish, Novodon modestus, skin to the total body weight were $4.6\%\;and\;5.0\%$ respectively. The optimum conditions for a $49.3\%$n yield Alaska pollack skin glue processing were considered the extraction of previously tinted in $0.1\%$ calcium hydroxide solution for 3 hours with the additional water as much as 3 times of sample weight at $70^{\circ}C$ for 3 hours under the controlled pH 5.0. The conditions for file fish skin glue were similar to those of Alaska pollack except the addition of five times of water to the weight of sample skin needed for extraction. The content of crude protein of Alaska pollack and file fish skin glue were $98.0\%\;and\;96.0\%$ respectively. The contents of crude ash and crude lipid were not different from that of chemical grade gelatin. Relative viscosity, melting point, gelation temperature and jelly strength of Alaska pollack skin glue marked 5.84, $21.8^{\circ}C,\;7.1^{\circ}C\;and\;10.0g$ respectively and those of file fish skin glue showed $5.79,\;25.0^{\circ}C,\;7.4^{\circ}C\;and\;11.6g$ respectively.The color and turbidity of Alaska pollack skin glue are slightly superior to those of file fish skin glue. It is supposed that the extract residue of skin glue is valuable for use the animal feeds by the results of amino acid composition. And the ratio of each amino acid content to the total amino acid of Alaska pollack and file fish skin glue is similar to that of chemical grade gelatin.