Starfish (Asterias rubens) as a New Source of Marine Lipids: Effect of Season, Size and Oil Extraction Methods

The increasing demand for oils that contain health-beneficial omega-3 fatty acids calls for new resources or better utilization of existing resources, such as side-streams or underutilized resources to maintain a sustainable fishery. Starfish has been, until recently, an unexploited resource with limited utilization. Currently, starfish is processed into starfish meal for feed. However, the content of bioactive compounds, such as omega-3 fatty acids and phospholipids, could make it a new source of marine oil containing omega-3 fatty acids for human consumption. The aim of this study was to map the composition of bioactive compounds in starfish and starfish meal at different harvesting times to elucidate the content and variation over seasons. The results showed that starfish is a good source of marine omega-3 fatty acids and rich in phospholipids. Some variation was observed in the composition, especially for EPA bound to phospholipids, which was significantly higher in the spring. Traditional extraction using heat and mechanical separation was not applicable to the starfish, and neither was enzyme-assisted extraction. On the other hand, the supercritical CO₂ extraction method using EtOH as a co-solvent seemed to be a promising green technology for extracting not only non-polar lipids, but also polar lipids, such as phospholipids. However, the conditions for extraction need further optimization.