Lipid changes in muscle tissue of ray (Raja clavata) during processing and frozen storage

Abstract

The object of the work was to analyze different lipid compounds (fatty acids and classes of lipids-phospholipids, triacylglycerides, free fatty acids, sterols, and sterol esters plus waxes) of ray muscle (Raja clauata) and to determine the possible changes originated in frozen storage at temperatures of -18 f 1 and -40 f 2 O C during 36 and 180 days, comparing the influence that the particle size (8 and 12 mm) of the mince has on the quality of the frozen ray muscle. On day 0, the main fatty acids detected, except 20:5n - 3, showed higher levels in the previously minced samples. The triacylglycerides were observed in the whole muscle, and the phospholipids represented the majority fraction. During the time in which the sample remained frozen, independent of the particle size and the freezing temperature, the levels increased in the storage period and the majority of the fatty acids. 22:5n - 3 and 22:6n - 3 experienced only slight variations. After 180 days and when minced ray muscle was used, higher quantities of polyunsaturated fatty acids and n - 3 HUFA were observed in the greater sized particle samples