南極オキアミの脂質含量および脂質成分に及ぼす漁期の影響

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This work was carried out to examine the effects of fishing season, body length, and body section of Antarctic krill Euphausia superba on the content, component, and fatty acid composition of lipid which was extracted from krill immediatedy after catch. The lipid content increased from 1.11% of wen weight krill in the initial season of fishing (December) to 3.95% in the terminal season (February, next year). Phospholipid occupied 63.6% of total lipid in the intial season, but decreased to 44.5% in the ternimal one. Triglyceride increased from 5.5% to 30.1%. Per cent of free fatty acid in total lipid ranged from 0.4 to 4.2. Total cholesterol was constant for different fishing seasons. Fatty acid composition was different according to fishing season: C14:0, C16:1, and C17:1 increased, while C20:5 and C22:6 decreased, toward the terminal season of fishing. Almost no differences in lipid content, lipid composition, or fatty acid composition were recognized in krill of various body length, except gravid krill, caught in the same fishing net. The lipid conten of cephalothorax was about 2 times that of abdomen. In the lipid of cephalothorax, phospholipid was 44.0% and trglyceride was 36.0%; in that of abdomen, phospholipid was 52.0% and triglyceride 29.1%. Astaxanthin decreased in the total lipid toward the terminal season of fishing, but ranged in 3-4mg against 100g wet weight krill through the fishing season.