Cilj ovog istraživanja bio je odrediti stupanj oksidacije masti, sastav masnih kiselina i njegove promjene tijekom deset mjeseci skladištenja zamrznute ribe. Istraživanje je provedeno na osliću (Merlucius merlucius) i skuši (Scomber scombrus). Korištene su metode mjerenja boje, stupanj oksidacije, ekstrakcija masti po Smedesu i plinska kromatografija. U obje je vrste utvrđen nizak udio masti. To je za oslića očekivano. Skuša je inače masna riba, a niski udio masti u ovom istraživanju povezan je s vremenom ulova. U obje vrste najizraženije su promjene boje. Minimalne su promjene u oksidaciji masti i sastavu masnih kiselina tijekom skladištenja. Polinezasićene masne kiseline s vrlo povoljnim učinkom na ljudsko zdravlje, EPA i DHA, nisu se značajnije smanjile tijekom skladištenja, ali zbog niskog udjela masti, obje analizirane ribe ne predstavljaju značajan izvor EPA i DHA.

The aim of this study was to determine the degree of fat oxidation, fatty acid composition and its changes in the period of ten months of frozen storage. The research was conducted on hake (Merluccius merluccius) and mackerel (Scomber scombrus). The methods used in this study were color measurement, oxidation, fat separation method by Smedes and gas chromatography. Low fat content was detected in both species. In hake it was expected. Mackerel is otherwise the fatty fish and low fat content in this study was associated with the time of harvest. In both fishes the biggest change is observed in color. The change in the fat oxidation and fatty acid composition during storage were minimal. Polyunsaturated fatty acids with strong benefit on human health, EPA and DHA, have not decreased during storage, but due to low fat content, both analyzed species do not represent significant source of EPA and DHA