Proximate composition of dorsal muscles of chum salmon Oncorhynchus keta

This investigation was carried out in order to elucidate the characteristics of dorsal muscles of chum salmon with low gonadsomatic index caught on the Rausu coast, Hokkaido. The contents of chemical components such as moisture, protein, lipid, ash, extractive-M, astaxanthin and mineral were determined by the ordinary method for the muscles of two males and four females. As a result, there is no appreciable difference in the contents of all the nutritive components between male and female. Proximate compositions of the muscles of male and female were 68.3+/-0.10% and 68.25+/-2.23% moisture, 16.23+/-0.96% and 16.91+/-0.93% protein, and 13.21+/-0.62% and 12.58+/-0.65% lipid, respectively. The characteristic of dorsal muscles of the chum salmon was the high lipid content and low contents of moisture and protein. In addition, the fatty acid compositions of total lipid, neutral lipid and polar lipid were determined by GLC method. The major fatty acids of total lipid and neutral lipid were C 14:0, C 16:0, C 18:0, C 16:1, C 18:1, C 20:1, C 22:1, C 20:5 and C 22:6. On the other hand, the major fatty acids of polar lipid were C 16:0, C 18:0, C 18:1, C 20:5 and C 22:6. The sum of these acids was more than 90% of the total fatty acids in each lipid. Contents of Fe, Zn, Cu and P were almost coincident with that of other chum salmon, and the Ca content was slightly low.