The effect of neutral and oxidized lipids on functionality in hake ( Merluccius merluccius L.): A dimethylamine- and formaldehyde-forming species during frozen storage

Abstract

The effect of added cod liver oil and oxidized cod liver oil on protein solubility, apparent viscosity and emulsifying capacity was measured during frozen storage of vacuum packed minced hake ( Merluccius merluccius L.), a species which forms dimethylamine (DMA) and formaldehyde (FA) during frozen storage. The results indicate that the samples with oxidized lipids added showed the best functionality during storage and the untreated control produced the worst. The DMA content was found to be inversely related to the degree of oxidation of lipids as measured by the TBA index, suggesting that the apparent protective effect of unoxidized and oxidized cod liver oil on protein functionality is due to a lower rate of FA and DMA formation. Electrophoretic studies indicated that differences existed in the types of interactions responsible for aggregation in the different treatments.