HomeInnovationAquaculture, reduction and upcycling of fish waste in proteins, Omega-3 and micronutrients

Aquaculture, reduction and upcycling of fish waste in proteins, Omega-3 and micronutrients

Innovation in aquaculture can allow the reduction of fish waste and their upcycling in proteins, marine Omega-3 fatty acids and various micronutrients. A study by the University of Stirling (Malcorps et al., 2021) – funded by the GAIN research project (EU, Horizon 2020) – examines the characteristics of some of the most widespread aquaculture fish in Europe, in view of the virtuous recovery of their by-products. (1)

1) Fish, consumption and needs of food security . Premise

The demand for products fish in Europe it is progressively increasing, as shown by EUMOFA data (European Market Observatory for Fisheries and Aquaculture Products). In 2021, spending on these products grew by 7%, to reach consumption per capita equal to about 23 kg/year. (2) The stock fish stocks on the other hand are decreasing, due to IUU (Illegal, Unreported and Unregulated fishing) to overfishing as well as pollution, climate change and other stressors for aquatic populations. (3)

Organic and regenerative aquaculture – integrated with algae, microalgae and molluscs – is the only one chance, as we have seen, to guarantee human beings adequate supplies of nutrients and micronutrients offered by fish species (4,5,6,7). In the medium term, the use of cellular agriculture is also envisaged to reproduce cells of various fish species, but the accessibility of this type of Alt-Fish in low- and middle-income countries (LMIC, Low-Middle Income Countries) will probably take further years. (8)

2) Fish, fish waste and food waste

Fish is largely underutilized due to a significant share of fish waste which is equally rich in nutrients and micronutrients but to date, beyond the rare hypotheses of fishmeal production for food use, (9) are destined for the production of feed or disposed of as waste.

The research is therefore oriented towards the development of efficient technologies forupcycling of fishing and aquaculture waste into food, nutraceutical and cosmetic ingredients. (10) The EcoeFISHent project, funded by the EU in HorizonEurope, begins, among other things, with the concentration of fish waste from industry and the retail. (11)

3) Nutritional value of fish waste

Scottish researchers (Malcorps et al., 2021) studied the characteristics of the most common fish in European aquaculture. Atlantic salmon, sea bass, sea bream, turbot and common carp (the only freshwater fish).

The fillets they represent on average 56% of the mass but the edible part, even before considering the extraction of nutrients and micronutrients with innovative technologies, reaches 70%.

The rejects they are characterized by their richness in Omega-3 fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), vitamins D and B12, iodine, selenium and other minerals.

4) Proteins and fatty acids

Proteins in fish waste from aquaculture they were found in a significant amount in the skin (20% the average, 23,4% that of the turbot in the upper extremity), the heads (13,1-20,2%), the frames (16,8, 19,4-15%), trimmings (lowest value 11,1% for common carp) and viscera (17,2-XNUMX%).

Fatty acids were found to be present to a greater extent in European sea bass (7,02 g/100 g), Atlantic salmon viscera (4,44 g/100 g) and common carp (4,07 g/100 g). Carp skin stands out for its saturated fat content (7,92 g/100 g), Atlantic salmon offal and trimmings and European sea bass for its polyunsaturated fatty acids (PUFA).

Omega-3s, EPA + DHA, were most significantly detected in the viscera of sea bass and in the heads, trimmings, skin of Atlantic salmon. Following, in the bones of the turbot. Among the aquaculture fish species examined, the common carp is instead the fish that shows the lowest values ​​of Omega-3 fatty acids. With variations always linked to the feed used.

5) How to reduce food losses (food loss)

The study under consideration (Malcorps et al., 2021) also proposes some solutions to reduce food losses in the processing phase of fish products (food loss), to increase the sustainability of processes in a circular economy logic.

5.1) Optimize made them.

Less selective processing than filleting can significantly reduce fish waste and increase the availability of edible parts (30 to 64% for turbot, 56% to 70% for salmon).

5.2) Upcycling.

The parts now considered fish waste should be recovered for human consumption, as is already largely the case in the artisan tradition and in the industrial processing of land animal carcasses.

6) Iceland Ocean Cluster, '100% Fish'

'100% Fish' is the project developed by Iceland Ocean Cluster to reduce waste and thus increase the profitability of fishing and aquaculture. Over the last 30 years, the use of fish by-products in Iceland has increased 30 times, to the point that today local cod producers use up to 80% of the raw material (compared to an average of 50% in the USA and Northern Europe).

Innovative technologies allow both the reduction and theupcycling of fish waste into a variety of food ingredients and products. As well as in bioactive compounds (peptides, collagen, chitin and chitosan, enzymes and biopolymers) for nutraceuticals, cosmetics and medicine. Fish in Iceland is valued in every way, even as a hide. (12)

7) Upcycling of fish waste, from Norway to Vietnam

Norway was one of the first countries to recognize fish by-products as a resource, with laws encouraging their use (for fish oil, feed and fertilizer) as early as 1639. Currently, Norway handles over 650.000 tons of fish by-products each year and the Atlantic salmon industry uses about 90% of its by-products.

Vietnam in turn, carefully separates and routes the pangasius fish waste to specific industries to reduce waste and create added value. And globally, there is growing interest in adopting strategies for other fish, crustacean and mollusc species.

8) Scotland, the case-study of the strategic use of fish waste from aquacultured salmon

Previous research of Sterling University (Stevens et al., 2018) – through exploratory scenarios based on a case-study – identifies that Scotland could increase food production from aquaculture Atlantic salmon waste by more than 60% from fish farms.

Il case-study expects a significant increase in by-product revenues (+803%) and sector profits (+5%), without the need to install new cages or use other marine resources. Moving the aquaculture industry towards a new era of production and processing, where to obtain a diverse range of products from a single species. (13)

9) Technological challenges

'The processing strategies and therefore the use of by-products depend on the food environment in general, including the consumption preferences which can vary greatly in Europe, from whole fish to various processed forms of different species.

Also, fish and seafood may contain chemical contaminants with related health implications and require investment in HACCP and decontamination to meet food quality requirements. (14) These attentions are obviously also required for the reuse of fish waste as ingredients for feed (e.g. protein meals and oils).

10) Provisional conclusions

'The analysis review highlighted the different nutrient profiles of by-product fractions, indicating that fish waste separation could offer better opportunities to maximize value addition and nutrient efficiency.

This could create incentives for processing and use, allowing the aquaculture industry to diversify its products and use marine resources more efficiently.

Consequently, increasing aquaculture production in terms of volume and value without using more resources is a perfect example of eco-intensification' (Malcorps et al., 2021).

Dario Dongo and Alessandra Mei


(1) W. Malcorps, RW Newton, M. Sprague, BD Glencross, DC Little (2021). Nutritional characterization of european aquaculture processing by-products to facilitate strategic utilisation. Front. Sustain. Food Syst., 20.10.21. Sec. Water-Smart Food Production, Vol. 5 – 2021. https://www.frontiersin.org/articles/10.3389/fsufs.2021.720595/full

(2) EUMOFA (2022). The EU fish market. https://www.eumofa.eu/documents/20178/521182/EFM2022_EN.pdf/5dbc9b7d-b87c-a897-5a3f-723b369fab08?t=1669215787975 The EU market overview https://www.eumofa.eu/the-eu-market

(3) Dario Dongo. Protection of fisheries and marine ecosystems, EU (in) action planGIFT (Great Italian Food Trade). 26.12.21

(4) Marta Strinati, Dario Dongo. Organic aquaculture, the latest chance. GIFT (Great Italian Food Trade). 25.2.19

(5) Marta Strinati. Algae and molluscs, aquaculture that regenerates the seasGIFT (Great Italian Food Trade). 10.11.19

(6) Giulia Paganini, Dario Dongo. 2022, the international year of artisanal fishing and aquacultureGIFT (Great Italian Food Trade). 3.1.22

(7) Dario Dongo, Alessandra Mei. Seafood Alg-ternative and Alt-Fish, microalgae in vegetable-based fish productsGIFT (Great Italian Food Trade). 12.4.23

(8) Dario Dongo. Cell cultured fish, the new frontier Biotech lands in EuropeGIFT (Great Italian Food Trade). 21.10.21

(9) Dario Dongo. Fishmeal, a huge unexpressed potential. GIFT (Great Italian Food Trade). 9.12.22

(10) Upcycling. Omega-3 from waste from the fish chainGIFT (Great Italian Food Trade). 29.10.21

(11) Dario Dongo, Andrea Adelmo Della Penna. EcoeFISHent, upcycling e Blue Economy in the fish supply chain. The EU research project. GIFT (Great Italian Food Trade). 18.10.21

(12) 100% Fish. https://www.sjavarklasinn.is/en/100-fish/Iceland Ocean Clusters

(13) Stevens, JR, Newton, RW, Tlusty, M., and Little, DC (2018). The rise of aquaculture by-products: increasing food production, value, and sustainability through strategic utilization. Mar. Policy 90, 115–124. doi: http://dx.doi.org/10.1016/j.marpol.2017.12.027

(14) Thomsen ST, Assunção R, Afonso C, Boué G, Cardoso C, Cubadda F, Garre A, Kruisselbrink JW, Mantovani A, Pitter JG, Poulsen M, Verhagen H, Ververis E, Voet HV, Watzl B, Pires SM (2022). Human health risk-benefit assessment of fish and other seafood: a scoping review. Crit Rev Food Sci Nutr. 2022;62(27):7479-7502. doi: 10.1080/10408398.2021.1915240

Alessandra Mei

Graduated in Law from the University of Bologna, she attended the Master in Food Law at the same University. You participate in the WIISE srl benefit team by dedicating yourself to European and international research and innovation projects.

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