| Popis: |
The liver tissue of the white seabream, Diplodus sargus, L. has been analysed. Fish specimens were obtained from the North Adriatic Sea, Croatia. The aim of this study was to determine the fatty acid compositions of neutral and polar lipid fractions from the liver of this fish appreciated in the mediterranean type of diet. Total lipids were extracted from the liver samples according to the method of Folch et al. The total lipid content, expressed on wet weight basis, amounted to 5, 9 +/- 1, 8 %. Neutral (triacylglycerols) and polar (phosphatidylinositol, phosphatidylserine, phosphatidylcholine, phosphatidlethanolamine) lipid fractions were separated from the total lipid extracts by thin-layer chromatography. The fatty acid compositions of neutral and polar lipid fractions were determined by gas chromatography of the corresponding methyl esters. There have been identified 18 different fatty acids. The unsaturated fatty acids were found to be very aboundant, comprising from 41, 9 to 74, 9 % of the total fatty acids. The major constituents of the total fatty acids identified in lipid fractions were polyunsaturates: docosahexaenoic (8, 1 – 23, 9 %), eicosapentaenoic (4, 5 – 8, 6 %) and arachidonic acid (4, 0 – 12, 0 %) ; monoenes: oleic (9, 8 – 19, 3 %) and palmitoleic acid (3, 9 – 10, 0 %) and saturates: palmitic (16, 8 – 34, 7 %) and stearic acid (4, 4 – 30, 0 %). The n-3/n-6 ratio, as a marker of biomedical importance for fish lipids was calculated. It was the highest for triacylglycerols, amounting to 4, 5. It was shown that the liver is a very good source of natural n-3 polyunsaturated fatty acids, which are well known for their many benefits in human health and diseases. |
