輸入ブラウンフィッシュミール中の脂質の性状

Abstract

The extracted lipids from imported brown fish meal were analyzed with respect to the following items: optical density at 450 mμ in benzene, TBA value, carbonyl value, cholesterol content, and fatty acid composition. Also the lipids were separated into seven fractions by silicic acid adsorption, alkali extraction, and Florisil column chromatography. Oxidized fish oil and white fish meal lipids were also examined to compare the results with those of brown fish meal. The results obtained are as follows; 1. Brown fish meal lipids show higher optical density, and TBA ratio (450mμ/530mμ), and lower cholesterol content than white meal lipids. Lower TBA value, and higher carbonyl and acid values are observed in the brown meal lipids but the difference from that of white meal lipids is not so distinct. 2. While the white meal lipids contain high 20:5 and 22:6 acids in the fatty acid composition, brown meal lipids show little amounts of these acids and high amounts of saturated and monounsaturated acids. 3. Compared with the results of oxidized fish oil, brown meal lipids show particularly higher optical density and TBA ratio, but their acid values and fatty acid composition patterns are similar to those of the 53°-7 day-oxidized fish oil. And furthermore, the weight patterns of the separated fractions of the former, though having an exceptional case out of five samples, are more consistent than that of the latter. This could possibly be attributed to tissue proteins in the meal where the lipids retained in the brown meal are protected from thorough oxidation.