Overfishing and growing pressure on marine ecosystems are driving the search for sustainable seafood alternatives. Within the LOCALITY project, two algae-enriched fish analogue prototypes, a vegan fish nugget and a jarred tuna alternative, have been successfully developed and scaled up. The work was carried out at the facilities of project partners GreenCoLab and IRTA, bringing algae-based seafood alternatives one step closer to the market.
Selecting the right microalgae
Earlier in the project, several algal species were thoroughly assessed for their nutritional, sensory and techno-functional properties. Based on the results, two microalgae were selected for further processing tests and formulation trials:
White Chlorella vulgaris has a neutral colour, which makes it easy to use in food products without affecting their appearance. It is a source of protein and unsaturated fatty acids and contains vitamin B12, a nutrient that is often lacking in vegan diets.
Vegan fish nuggets: produced at GreenCoLab
To develop the fish nugget analogue, the team tested various ingredient combinations and different inclusion levels of white Chlorella vulgaris biomass and a Tetraselmis chui extract. The aim was to reproduce the appearance, texture and sensory characteristics of fish while preserving the nutritional and functional benefits of the microalgae.
Production was successfully scaled up at GreenCoLab, resulting in 10 kg of product. The nuggets were then frozen and stored for an upcoming consumer study. This demonstrates that both microalgae can be used as viable ingredients in a fish nugget product.
Jarred tuna alternative: produced at IRTA
Tuna has a distinctive fibrous texture that is difficult to replicate. To achieve it, the team used extrusion, a food processing technology that aligns proteins into fibre-like structures. Both low- and high-moisture extrusion experiments were carried out using formulations containing plant proteins and microalgae. The best results came from combining low-moisture extruded soy protein with white Chlorella vulgaris and other ingredients.
Production was successfully scaled up at the IRTA pilot plant, yielding 80 jars with a total of 12 kg of product. The shelf-stable jars are being stored at room temperature ahead of consumer testing.
A step towards commercial algae-based foods
Together, these scale-up activities show that microalgal ingredients can be successfully incorporated into seafood alternatives and confirm their potential for industrial production and future commercialisation. The prototypes will now be used in LOCALITY’s planned consumer study and demonstration activities.
This work supports LOCALITY’s objective of delivering sustainable, vegan and algae-based food products at a near-commercial stage, while contributing to the protection of Europe’s aquatic ecosystems.
Photo credits for jarred tuna to IRTA and for the fish nuggets to GreenCoLab.