Chemical Components and Fatty Acid Composition of Lipids in Several Fresh Water Fishes except Cyprinidae in Lake Biwa

Abstract

The proximate composition of various tissues and the fatty acid composition of their lipids in several fishes except Cyprinidae in Lake Biwa were determined in order to evaluate the nutritive value of fresh water fish. The fishes examined were namazu Silurus asotus, nijimasu Salmo gairdneri, biwamasu Oncorhynchus masou rhodurus, ayu Plecoglossus altivelis, ohkuchibasu Micropterus salmoides, bluegill Lepomrs macrochirus, unagi Anguilla japonica, yoshinoboti Rhino- gobius brunneus, and isaza Chaenogobius isaza.
The results obtained were as follows.
(1) The contents of moisture, crude ash, crude protein and crude lipid in edible portions were 68.3-84.6, 1.0-3.1, 12.1-22.5 and 1.2-16.2%, respectively. The lipid contents in the edible portions of biwamasu and unagi were much higher than those in the edible portions of other fishes,
(2) Lipids of the edible portions were rich in palmitic acid (C_16:0, ), palmitoleic acid (C_16:1ω9)and oleic acid(C_18=1ω9).
(3) The content of total polyunsaturated fatty acid was lower in lipids of the muscles or the whole bodies of fresh water fishes than in those of the muscles of marine fishes.