Seasonal variation in the chemical composition of horse-mackerel (Trachurus trachurus)

Chemical analysis was performed on samples of horse mackerel (Trachurus tra churus L.) caught monthly off the Portuguese coast throughout a period of o ne year (May 1997-April 1998). In the period between August and January the amount of total lipids present was recorded showing a minimum in February. Protein content remained fairly constant during the whole one-year period. Seasonal variation of lipid classes was followed and fatty acid profiles o f total, polar and nonpolar lipids as well as that of phosphatidylcholine ( PC) and phosphatidylethanolamine (PE) were determined. The non-polar lipids were the ever dominant group, mainly composed of triacylglycerols. Phospha tidylcholine (PC) and phosphatidylethanolamine (PE) were the main phospholi pids mainly containing 20:5 omega3 and 22:6 omega3, but PE was richer in 22 :6 omega3. Thus this species is all year long an adequate element of the traditional P ortuguese diet, and contributes to the omega3 intake.