This study also shows that it is possible to reduce the use of fishmeal in farmed sea bass feed by using food industry by-products, without compromising the growth or nutritional value of the fish.
The study, led by researchers from CIIMAR, and published in the international scientific journal Aquaculture Nutrition, indicates that it is possible to reduce the use of fishmeal in farmed sea bass feed by using food industry by-products, without compromising the growth or nutritional value of the fish. The study also revealed a significant increase in the absorption of iron by fish, a mineral essential for human health. The research was carried out as part of the Pep4Fish project, funded by the Blue Bioeconomy Pact through the Recovery and Resilience Plan (PRR).
The Portuguese study “Locally-Sourced Animal Protein Hydrolysates in High-Plant-Protein Diets Can Promote European Seabass Growth and Nutrient Utilization, Reducing Reliance on Fishmeal” uses a circular economy approach, transforming food industry by-products – such as non-consumable parts of fish, blue shark skin and pig by-products – into high-value food ingredients for fish. These ingredients are obtained through a process that ‘pre-digests’ the proteins, transforming them into small particles that are easier for sea bass to absorb.
For 89 days, juvenile sea bass were fed diets that replaced part of the fishmeal with these innovative ingredients (hydrolysates). The results showed that the fish grew normally, maintained high feed efficiency and produced high-quality fillets with omega-3 levels suitable for a healthy diet. In other words, it was possible to reduce dependence on fishmeal, a limited resource, without any loss of quality for the consumer.
But the most innovative result of the study was the very significant increase in iron bioavailability. The diets tested allowed sea bass to absorb up to three times more iron than fish fed the traditional diet. In practice, this means that fish make better use of this essential mineral if they are fed the hydrolysates developed. The researchers explain that this effect is due to the way these processed proteins bind to iron, facilitating its absorption by the intestine.
This advance has a significant impact by promoting more sustainable aquaculture, which reuses by-products, reduces waste, decreases pressure on marine resources, and strengthens the autonomy of national fish feed production.
Promoted by the Blue Bioeconomy Pact and financed through the Recovery and Resilience Plan (PRR), Pep4Fish represents a strategic investment to make Portugal a European leader in the sustainable use of marine resources and the creation of more efficient, circular nutrition solutions with a smaller environmental footprint.
The project consortium brings together companies and research centres working together to develop hydrolysed protein and other functional ingredients capable of modernising aquaculture and strengthening the sector’s competitiveness. It is led by the ETSA Group and brings together nine partners: AgroGrIN Tech, B2E – CoLAB for the Blue Bioeconomy, CIIMAR, Seaculture, Savinor, Sorgal, Sebol, ITS – Sub-product Processing Industry and the School of Biotechnology of the Portuguese Catholic University.
