• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.423-428
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• 1998

The effective extraction methods and chemical components of crude polysaccharides of ascidian tunics were investigated. Tow extraction conditions, autoclaving or enzyme treatment, were applied. The proximate composition of ascidian tunics was not much different between those dried in raw (containing pigments) and those acetone treated and dried (decolorized), showing $50\%$ of carbohydrate and $40\%$ of protein. It was possible to extract up to $10\%$ of crude polysaccharides from ascidian tunics regardless of the extraction methods, autoclaving or enzyme treatment. In case of the latter the extraction yield by neutrase was higher than that with alkalase (Novo co.) or mixture 2000 (Pacific chemical co.). The most effective enzyme concentration and extraction time appeared to be 24 hrs of extraction with $3\%$ neutrase. On the other hand, in autoclave treatment, 6 hrs extraction showed most desirable extraction yield, about $9.7\%$. The compositions of amino acid of decolorized ascidian tunic (acetone treated group) and the crude polysaccharide from the autoclaving (water solubles) or neutrase treatment (enzyme digestibles) were similar to each other. Histidine was the highest both in the neutrase and autoclave treatment group and the yield were $29.2\%,\;20.4\%$, respectively, followed by aspartic acid and glutamic acid. Among the minerals, the content of Ca was significantly high, followed by Mg and Na.