The changes of fatty acid composition in sun dried, oven dried and frozen hake (Merluccius merluccius) and sardinella (Sardinella aurita)

M El Cafsi, I Rabeh, K Telahig

Abstract

The fatty acid composition and fat quality alteration of the round sardinella (Sardinella aurita) and the European hake (Merluccius merluccius) fillets during the frozen storage (-30°C), sun drying and controlled oven drying (temperature = 60°C, air velocity = 2 m/s and relative humidity = 20%) were investigated. Results show that the fresh fillets of the S. aurita and M. merluccius were particularly rich in polyunsaturated fatty acid mainly the Docosahexaenoic Acid (DHA) and eicosapentaenoic acid (EPA). Changes in the saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-3 polyunsaturated fatty acids (n-3PUFA), n3/n-6 ratio, atherogenic (AI), thrombogenic (TI) and polyene indices (PI) revealed that both freezing and drying (solar and oven) processes affected the lipid nutritional quality at different degrees in the two studied species. The frozen storage induced a high alteration of the sardinella fillet fat; however, the hake was more susceptible to the oven drying treatment.