Supercritical CO2 extraction increases the recovery levels of omega-3 fatty acids in Tetraselmis chuii extracts

Tetraselmis chuii is a microalgae marketed as ingredient meeting the acceptance criteria for novel foods established by the European Union and can be an important source of healthy fatty acids (FA). The aim of this research was to characterize the FA profile of T. chuii fractions obtained by supercritical carbon dioxide (SCCO2) extraction operating with two sequential co-solvents and to evaluate the effect of biomass pretreatment (freeze/thaw cycles followed by ultrasounds). T. chuii biomass was confirmed to be an important source of omega-3 FA, mainly due to the abundance of α-linolenic acid, and pre-treatment significantly improved the lipid yield. Other omega-3 FA, such as 16:3, 16:4, 18:4, 18:5, 20:3 and 20:5, were also detected in different proportions. When SCCO2 extraction of pretreated and un-pretreated T. chuii was compared with conventional solvent extraction, the nutritional quality indices of the extracts were improved by the use of SCCO2. •Tetraselmis chuii was confirmed as an important source of omega-3 fatty acids (FA).•Supercritical CO2 (SCCO2) extraction improved the FA profile of T. chuii.•Freeze/thaw cycles combined with ultrasounds increased SCCO2 extraction yield to 5.2%.•SCCO2 lipid yield was 0.98% and 4.21% with EtAc and EtOH co-solvents, respectively.•SCCO2 lipid extracts obtained from pretreated T. chuii contained 44% of omega-3 FA.