The experiment was performed concerning the physical property, content of polysaccharides, and composition of alginates and metals of the wakame fronds before and after treatment with 3 percent acetic acid solution. The results obtained are as follows.
1) The breaking strength and the stifiness of the wakame fronds rose in a short time by treatment with acetic acid, and after that the rise was hardly observed.
2) The fraction of (WSP) decreased, and the fraction of water insoluble polysacchirde (WIP) inceased after treatment of the fronds with acetic acid.
3) The acid soluble alginate was found a little more in the WSP tha in the WIP, while after treating with acetic acid this alginate increased in the WIP.
4) About 50 to 60 percent of metals bound to polysaccharide of the fronds sliminated by treatment with acetic acid, and the rate of the metals beccame in the order of Na, K, Mg and Ca.
5) It is assumed that the increase of the WIP of the fronds made the fronds stiff after treating with acetic acid, and that the increase was due to the elimination of metals from the polysaccharides by treatment with acetic acid.
6) Sedimentation constants, polymerization degrees, molecular shapes, activation energies and bound water contents of Na-alginate scarcely by treatment with acetic acid.