Impact of processing on n-3 LC-PUFA in model systems enriched with microalgae

Microalgae have already shown their potential as an alternative source of n-3 LC-PUFA. In this study, 5 different microalgal species (Isochrysis, Nannochloropsis, Phaeodactylum, Porphyridium and Schizochytrium) were added to an acidic model system and screened on their potential use in acidic food matrices. The impact of mechanical and thermal processing on the model systems was studied by analyzing the amount of n-3 LC-PUFA, free fatty acids, carotenoids, lipid polymers and the oxidative stability. A (limited) reduction of n-3 LC-PUFA was observed. Thermal alterations combined with the presence of free fatty acids seemed to be the causing factor for this decrease. Furthermore, the oxidative stability of model systems enriched with photoautotrophic microalgae was significantly higher than of those enriched with heterotrophic microalgae. It can therefore be concluded that photoautotrophic microalgae low in initial free fatty acid content are a promising source of n-3 LC-PUFA in thermally processed acidic food systems.