Phospholipids of tuna white muscle

The composition of the lipids from the white muscle of five tuna fish has been determined. Total extractable lipid varied from 0.5%舑10.3% of the tissue wet weight; phospholipid content ranged from 0.3%舑0.6%. The separation of the phospholipid components was made by column chromatography with activated silicic acid and stepwise elution, with increasing concentrations of methanol in chloroform. The components were identified by chemical tests and infrared (IR) spectra. Tuna white musele contained an average of 0.5% phospholipid on wet weight basis; 23% was cephalin, 54% lecithin, 8% sphingomyelin, 2% phosphoinositide, with small amounts of unidentified components. Ten to 30% of the lecithin and cephalin fractions were in the form of plasmalogens. The gas‐liquid chromatographic analyses of the 12舑22 carbon fatty acids of the lecithin, cephalin, and neutral fractions are presented. The cephalins were characteristically high in stearie acid and low in palmitic acid, in contrast to the lecithins.