Lipids and of fatty acids of edible crabs of the north-western Pacific

Analyses of lipids and fatty acids in muscles and hepatopancreas of five commercially exploited crabs inhabiting the Sea of Japan and the Okhotsk Sea, namely Paralithodes camtschaticus, Paralithodes platypus, Chionoecetes opilio, Chionoecetes angulatus and Chionoecetes japonicus, have been carried out. The total lipid level (TL) in muscles ranged from 0.53% of wet weight (ww) to 1.57% of ww and the amount of phospholipids exceeded that of triglycerides. The TL contents in the hepatopancreas of all crabs were higher than in muscles and varied between 10.2% ww in C. angulatus and 19.8% ww in P. platypus, the major class of lipids being triglycerides. The main polar lipids in the hepatopancreas and muscles were phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Among polyunsaturated fatty acids (PUFAs), the n-3 fatty acids have dominated; 16:0, 18:1n-9, 20:5n-3 and 22:6n-3 were the main fatty acids contained in the tissues studied. In all the crabs, excluding C. angulatus, the PUFAs n-3/n-6 ratio in muscles varied between 7.02 and 10.3 while, in the hepatopancreas, the ratio varied between 4.00 and 6.62.