SUMMARY: Lipid classes and fatty acid compositions of the muscles and eggs of wild and cultured sweet smelt in Korea from different habitats and fish culture farms were compared. Non‐polar lipid (NL) content was in proportion to total lipid (TL) content and higher in the cultured fish muscles and eggs than in the wild fish. Phospholipid (PL) content showed almost no difference between the wild and cultured fish muscles. The fish eggs contained approximately three times as much PL as the fish muscles. The prominent NL classes of the fish muscles were triglyceride (TG) and free sterol (ST), and additionally, sterol ester (SE) was one of the prominent NL classes in the fish eggs. Each of the cultured fish muscles or eggs had proportions higher in TG and lower in ST compared with those of wild fish, respectively. These NL class proportions in fish muscles showed almost no difference in association with their wild habitats, fish culture farms as well as sex, while those in the fish eggs differed significantly. The PL class proportions of the fish muscles were similar in all samples, except those of the fish cultured in Miryang City. The wild fish muscles were rich in 16:1n‐7, 18:3n‐3 and 20:5n‐3, whereas the fatty acid proportions showed almost no differences between fish habitats. The cultured fish muscles were rich in 18:1n‐9, 18:2n‐6, and 22:6n‐3, in which the fatty acid proportions showed significant difference between fish farms due to different diets.

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Changes in the proximate composition, lipid classes, and fatty acids were studied in chub mackerel Scomber japonicus and Japanese jack mackerel Trachurus japonicus muscles cooked using a frying pan, oven, and microwave oven. The moisture content was high in the raw samples (chub mackerel 65.5%, Japanese jack mackerel 60.5%) and decreased with cooking, especially in the frying pan method (chub mackerel 49.2%, Japanese jack mackerel 49.8%). In contrast, the protein, lipid and ash contents increased significantly with cooking in chub mackerel muscle (P<0.05). However, the lipid content of Japanese jack mackerel muscle showed no significant difference between the samples using the three cooking methods and the raw sample. The dripped lipid contents from the cooked muscles showed the highest levels in the frying pan samples and the lowest levels in the microwave oven samples. The percentage of non-polar lipid (NL) in the total lipid content was over 95% in the muscle lipids (10.43-21.86 g/100 g sample). Prominent fatty acids were 16:0, 18:1n-9, 22:6n-3 (docosahexaenoic acid, DHA), 16:1n-7 and 20:5n-3 (eicosapentaenoic acid, EPA) in both fish muscles and dripped lipids. There was no change in the EPA level in any of the fish muscles, by any cooking method. The percentage of DHA in the muscle of chub mackerel showed the lowest level in the frying pan sample and the highest level in the microwave oven and raw samples, and an intermediate level in the oven sample. However, the percentage of DHA in the Japanese jack mackerel muscle was not significantly different between the various cooking methods. From these results, the microwave oven and oven cooking methods showed relatively low levels of dripped lipid content and loss of n-3 PUFA compared with the frying pan cooking method.

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