Background: Fish and marine animals fat is a source of unique long chain polyunsaturated fatty acids (LC-PUFA): eicosapentaenoic (EPA), docosahexaenoic (DHA) and dipicolinic (DPA). These compounds have a beneficial influence on blood lipid profile and they reduce the risk of cardiovascular diseases, atherosclerosis and disorders of central nervous system. The proper ratio of n-6/n-3 fatty acids in diet is necessary to maintain a balance between the effects of eicosanoids synthesized from these acids in the body.
Objective: The aim of this study was the evaluation of total fat and cholesterol content and percentage of fatty acids in selected commercial smoked marine fish.
Material and methods: The studied samples were smoked marine fish such as: halibut, mackerel, bloater and sprat. The percentage total fat content in edible muscles was evaluated via the Folch modified method. The fat was extracted via the Bligh-Dyer modified method. The enzymatic hydrolysis was used to assesses cholesterol content in samples. The content of fatty acids, expressed as methyl esters, was evaluated with gas chromatography.
Results: The average content of total fat in 100 g of fillet of halibut, mackerel, bloater and sprat amounted respectively to: 14.5 g, 25.7 g, 13.9 g and 13.9 g. The average content of cholesterol in 100 g of halibut, mackerel, bloater and sprat was respectively: 54.5 mg, 51.5 mg, 57.5 mg and 130.9 mg. The amount of saturated fatty acids (SFA) was about 1/4 of total fatty acids in the analyzed samples. The oleic acid (C18:1 n-9) was the major compound among monounsaturated fatty acids (MUFA) and amounted to 44% of these fatty acids. The percentage of polyunsaturated fatty acids (PUFA) in halibut, mackerel, bloater and sprat was respectively: 31.9%, 45.4%, 40.8% and 37.0%. The percentage of n-3 PUFA in mackerel and bloater was 30.1% and 30.2%, while in halibut and sprat was lower and amounted to 22.5% and 25.6%, respectively.
Conclusions: In terms of nutritional magnitude the meat of mackerel and herring, compared to the meat of sprat and halibut has a much better n-3 PUFA content, while relatively low content of cholesterol.