Waste generated by the fishing industry — often treated merely as waste — may hide a high nutritional, environmental and economic value.
The discovery was made by a group of researchers led by the University of Aveiro (UA). Two by-products from Cape hake processing (Merluccius capensis) were analyzed: the trimmings (head and tail, usually discarded) and the leftovers resulting from the cutting and filleting process.
The study, published in the journal Applied Food Research, reveals that these materials are rich in bioactive lipids with potential applications in the food, pharmaceutical and cosmetic sectors.
In a statement, the scientists explained that advanced chemical analysis techniques were used to characterize in detail the lipids present in these by-products. The results show that, although both are valuable sources of beneficial compounds, they exhibit distinct lipid profiles.
The fish residues resulting from cutting and filleting revealed higher quantities of ash, proteins and total lipids, as well as higher levels of certain fatty acids, such as palmitic acid and oleic acid. On the other hand, the trimmings stood out for a greater abundance of phospholipids, particularly phosphatidylcholines, which are essential molecules for cell structure and with multiple industrial applications.
Despite these differences, the researcher João Monteiro notes, “both sub-products showed similar amounts of marine phospholipids and omega-3-rich phospholipids, including EPA and DHA, known for their benefits to cardiovascular and brain health.” The scientist also states that “the lipid extracts from both demonstrated significant anti-inflammatory activity in laboratory assays.”
“Cape hake is a case study, but the concept is much broader,” says the investigator. And he adds that “marine species with similar lipid profiles, notably other lean or semi-fatty fish rich in omega-3, likewise produce large volumes of by-products during industrial processing.”
The study also involved the collaboration of the Vasco da Gama University School, the University of Perugia (Italy), the Portuguese Institute for the Sea and the Atmosphere and the University of Porto.
Sustainable alternative to conventional lecithins
The research team is convinced that one of the most promising aspects of the study is the potential of these marine lipids as an alternative to traditional lecithins, usually obtained from soy or eggs.
Lecithins, explains João Monteiro, “are widely used as emulsifiers and stabilizers in the food industry, but there is growing demand for natural, sustainable ingredients with additional bioactive properties.”
Therefore, the phospholipids extracted from hake by-products could be used in the development of functional foods and nutritional supplements, addressing new consumer demands while simultaneously promoting the valorization of marine resources hitherto underutilized.
Positive economic and environmental impact
The valorization of these residues also represents an opportunity to make the fishing industry more sustainable, the researchers argue. By transforming by-products into high-value raw materials, João Monteiro notes, “it is possible to reduce waste, increase the efficiency of production processes and promote a circular economy in the fisheries sector.”
Beyond the food sector, the identified compounds could be applied in nutraceutical, pharmaceutical and cosmeceutical products, thanks to their bioactive properties, notably anti-inflammatory.
The researchers argue that future studies should focus on optimizing the extraction and purification methods of these lipids, in order to maximize their recovery and explore their full functional potential.
