The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020). To FCT for the contracts of J. Pinela (CEECIND/01011/2018) and L. Barros (through the institutional scientific employment program-contract). This work was funded by the European Regional Development Fund (ERDF) through the Competitiveness and Internationalization Operational Program (POCI), within the scope of project HealthyPETFOOD (POCI-01-0247-FEDER-047073), and by BBI-JU through the H2020 Project AQUABIOPRO-FIT
“Aquaculture and agriculture biomass side streams proteins and bioactives for feed, fitness, and health promoting nutritional supplements” (Grant number 790956).
The efficiency of the microwave-assisted extraction (MAE) technique on recovering nutritional and bioactive oils
from salmon (Salmo salar) side streams was evaluated and compared to Soxhlet extraction. The response surface
methodology (RSM) coupled with a central composite rotatable design was used to optimize time, microwave
power, and solid/liquid ratio of the MAE process in terms of oil yield. The optimal MAE conditions were 14.6
min, 291.9 W, 80.1 g/L for backbones, 10.8 min, 50.0 W, 80.0 g/L for heads, and 14.3 min, 960.6 W, 99.5 g/L for
viscera, which resulted in a recovery of 69% of the total lipid content for backbones and heads and 92% for
viscera. The oils obtained under optimal MAE conditions showed a healthy lipid profile as well as cytotoxic,
antioxidant, anti-inflammatory, or antimicrobial properties. These results highlight that oils from underutilized
salmon by-products could be exploited by different industrial sectors under the circular economy approach.
