Background. As a result of consumer acceptance and low price production, sales of striped catfish fillets continue to grow. Striped catfish fillets, due to their white meat and lack of fish scent, can be an altemative to fish such as cod or hake. The paper analysed the influence of four different kinds of heat treatment: boiling with and without the addition of salt, frying, microwave cooking, microwave cooking without water) on the composition of fatty acids and the lipid oxidation and hydrolysis level of striped catfish fillets. Material and methods. Assays were performed on striped catfish fillets (Pangasius hypophthalmus, Sauvage 1878), which were bought from local supermarket. Fillets one year before expiration date were assayed. Quality of fish lipids was determined by an analysis of the following factors: peroxide value (PV), anisidine value (AsV), TOTOX value, conjugated dienes (CD), acid value (AV), along with an analysis of the composition of fatty acid (FA) via gas chromatography. Results. It was shown that conventional cooking and microwave cooking of striped catfish fillets results in an approximately 10% change in the amount of PUFA, including EPA and DHA, whereas the percentages of SFA and MUFA remain unchanged. The amount of the sum of EPA and DHA in 100 g of raw fillet was 16.5 mg, whereas after conventional cooking, microwave cooking and frying the sum of EPA and DHA was respectively: 12, 22 and 23 mg. It was observed that conventional cooking causes an average 10% loss of fat, a change not observed in case of microwave cooking. In spite of a substantial influence of heat treatment on the amount of both primary and secondary oxidation products, striped catfish lipids maintained good quality after the treatment - PV of every sample was below 3 meq 02/kg lipids, and AsV below 1.5. The addition of salt during boiling caused a 16-fold increase in the amount of peroxides and a fourfold increase in the amount of secondary oxidation products. Conclusions. A 100 g portion of fillet, depending on the applied method of heat treatment delivers between 12 and 23 mg of the EPA + DHA sum, which is as little as 2.5 to 5% of daily reference value for these acids. Taking into account that n-3 PUFA deficiency involves mainly long-chain acids, striped catfish fillets are not a valuable source of these acids, however, due to low fat content and a proper n-6/n-3 PUFA ratio they can be alter- native to products such as pork. When cooking catfish fillets in salted water it is worth bearing in mind that their oxidation level will greatly increase.
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