Odour characteristics of seafood flavour formulations produced with fish by-products incorporating EPA, DHA and fish oil

• Thermal degradation of EPA and DHA was analysed for fatty acids and volatiles.
• Aroma of fish powder systems with addition of ω-fatty acids was investigated.
• Hexanal, 2,4-heptadienal and 4-heptenal were found after heating EPA and DHA.
• EPA and DHA added to model systems increased the fish aroma compounds.
• Panellists only differentiated samples fortified with fish oil and EPA.

Thermal degradation of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids was investigated. As a novelty, EPA, DHA or fish oil (FO) were incorporated as ω-fatty acid sources into model systems containing fish powder produced via Maillard reactions. Aroma composition of the resulting products was determined and complemented with sensory evaluation. Heating of the oils led to a fast decrease of both, EPA and DHA, and to the development of characteristic volatile compounds including hexanal, 2,4-heptadienal and 4-heptenal, the most abundant being (E,E)-2,4-heptadienal (132 ± 44–329 ± 122 μmol/g). EPA and DHA addition to the model systems increased the concentration of these characteristic volatile compounds. However, it did not have a considerable impact on the development of characteristic Maillard reaction products, such as pyrazines and some aldehydes. Finally, the results of the sensory evaluation illustrated that panellists would chose samples fortified with FO as the ones with a more pleasant aroma.