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.
