Fatty acid composition of thermally processed milkfish (Chanos chanos)

Abstract

The lipid profile of smoked, retort pouched milkfish (Chanos chanos) steaks were evaluated. Dressed milkfish steaks were brined in 2% brine solution and thereafter smoked at 70⁰C for 2 h. Samples were processed in two forms of dry-pack and in oil medium using refined sunflower oil. Linoleic acid (LA) was the major constituent of the filling medium (61.19%) and the unsaturated fatty acid content of the oil was 88.65%. This led to samples processed in oil to have high PUFA (51.18%) and LA (33.40%). PUFA Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) decreased after processing. The values in the raw sample before processing were 7.91% and 16.83% respectively, these decreased after processing to 5.99%, 4.08% and 3.73 for EPA and 14.96%, 11.79% and 7.96% for DHA. This study indicated that retort sterilization using smoking as a pretreatment had significant effect on fatty acid composition of milkfish. Though EPA and DHA reduced after processing, essential fatty acids LA and ALA increased. Despite the changes that were observed in the fatty acid composition of milkfish after processing, the ratio of omega-3 fatty acids to omega-6 fatty acid was within the acceptable standard recommended by WHO.

Keywords: Milkfish, retort sterilization, PUFA, eicosapentaenoic acid; docosahexaenoic acid, linoleic acid