Effects of processing and ice storage on lipid classes and fatty acids of ray muscle ( Raja clavata)

Abstract

The effect of ice storage on the lipid material (total lipids, lipid classes and fatty acids) of whole and minced ray muscle has been studied. Neither processing nor ice storage for seven days significantly changed ( p > 0.05) the total lipid content. The main fatty acids were: 22:6n-3, 16:0, 18:1n-9, 18:0, 20:5n-3, 20:4n-6, and 22:5n-3 in both whole and minced ray muscle. The contents of these fatty acids increased significantly ( p < 0.001) during seven days of storage in the ice state, except those of 20:4n-6 and 20:5n-3, which decreased significantly ( p < 0.01). The contents of the different fatty acids (saturated, monoenes, and polyunsaturated) increased significantly ( p < 0.001) owing to both mincing and storage in ice. Phospholipids, sterol esters + waxes, triacylglycerides, free fatty acids, and sterols were studied. Phospholipids were the main lipid group in ray muscle. No significant differences ( p < 0.01) were found as a consequence of mincing and ice storage in the contents of phospholipids and sterols. However, significant differences ( p < 0.01) appeared in the free-fatty-acid content after seven days of storage in ice, but mincing did not affect this.