"Meat from algae": how microalgae and soy become the future cutlets

Who can we trust with the new protein for the frying pan planet? Materials scientist Stefan Guldin (TUM/TUMCREATE, Proteins4Singapore project) shows an unconventional answer: microalgae + soy. In a recent article in Nature, he explains how raw materials are obtained from single-cell cultures with 60-70% protein, and then “tuned” its self-assembly and texture to imitate the “meat” bite and juiciness. The context is Singapore’s “30 by 30” goal: to produce 30% of food locally by 2030 in a land-scarce environment, where compact algae bioreactors look especially logical.

Background of the study

Alternative protein sources are not a fashionable whim, but a response to several bottlenecks at once: population growth, climate constraints, land and water shortages, and in some megacities, the vulnerability of import-dependent supply chains. Singapore is a case in point: the country imports the lion's share of its food and has set a "30x30" goal - to produce 30% of its diet domestically by 2030. In such a geography, compact bioreactors and closed photobioreactors with microalgae are logical: they require almost no soil, operate all year round, and are scalable "by city" rather than "by hectare."

Microalgae are interesting not only for their “vertical” production. A number of strains ( Chlorella, Nannochloropsis, Arthrospira/“spirulina” ) provide 50-70% protein in dry matter, and polyunsaturated fatty acids, pigments and antioxidants come along with the protein. Protein concentrates and isolators can be obtained from such biomass – “building blocks” for food systems. Their advantage over many land-based crops is the flexibility of composition through control of cultivation conditions and independence from seasonality: production batches are easier to standardize.

But the "green powder" does not turn into a "cutlet" by itself. Algal proteins have a specific profile of taste and aroma (chlorophylls, "marine" note), variable solubility and gelation, and strong cell walls make digestibility difficult if not processed correctly. Hence the technological conveyor: fractionation, bleaching/deodorization, adjustment of functional properties (emulsification, water retention, viscoelasticity). At the same time, drying and separation of biomass must be done energy-efficiently, otherwise part of the environmental and price gain is lost; add here the "novel food" regulation and the issue of allergens - and it becomes clear why the path from the reactor to the counter is long.

The key to the “meat” experience is structuring. Protein concentrates must be forced to self-organize into a fibrous, layered microstructure that provides an elastic “bite” and retains juices and fat. This is achieved through shear fields, extrusion, microphase separation control, and the addition of lipids/aromatic precursors. In practice, algal protein is often blended with soy protein: this makes it easier to hit the right amino acid profile, improve texture formation, and “knock down” the algal flavor. The final barrier is the consumer: we need recipes for local cuisines, blind tastings, and clear labeling. This is why materials science and sensory tools are added to food chemistry algorithms: without them, “algae meat” will remain a laboratory demonstration, not a product that people will buy a second time.

Why microalgae?

• Protein to the brim. Some types provide up to 60-70% protein in dry matter - comparable and higher than typical sources.
• Urban format. They grow in reactors, almost without land and with a small water footprint - convenient for a megacity like Singapore.
• Flexible processing. Protein fractions are extracted from biomass, which can be used as texture "constructors".

What is Guldin's team doing?

The research focus is how to make plant proteins behave like "meat". The materials science approach is decisive here: by controlling the self-organization of protein threads and their interaction with water and fats, it is possible to assemble the desired microstructure - layering, fibrousness, elasticity. This is the case when the "physics of soft matter" works to taste.

• Raw materials: a mixture of microalgae and soy proteins - a balance of taste, nutrition and price.
• Process: extraction → selection of self-assembly conditions → mint/chew and juiciness tests → recipe adjustments.
• Venue: TUMCREATE/Proteins4Singapore consortium - a bridge between foundations and food technologies to meet the needs of the city-state.

What is already clear - and what is slowing down the "alt-meat" on algae

• Pros:
  • high protein density and complete amino acid profile in a number of species;
  • scalability in closed systems;
  • the prospect of reducing carbon and water footprints.
• Challenges:
  • taste and aroma (chlorophylls, “marine” notes) require masking and bleaching of pigments;
  • functional properties (solubility, gelling) vary between species and depend on processing;
  • economics and regulation: stability of crop supply chains, standardization of protein concentrates.

Why Singapore (and not only) needs this

Singapore imports >90% of its food and aims to produce 30% of its food locally by 2030. Compact microalgae reactors + protein processing into "meat" products are a way to add grams of protein per square meter and reduce vulnerability to supply shocks. The same is true for cities with land and water shortages.

How to make a "meat bite" from "green porridge"

• Structure: controls microphase separation and orientation of protein fibers (extrusion, shear fields) - hence the fibrousness and "wave" when bitten.
• Juiciness: encapsulates fats, binds water with hydrocolloids - imitation of "meat juice".
• Taste: fermentation, selection of lipid profile and aromatic precursors - moving away from the "seaweed" note towards "umami".

What's Next for Proteins4Singapore

• From laboratory to mini-workshops: batch stability, shelf life, cold logistics.
• Dietetics and safety: plant protein allergens, digestibility, labeling.
• Consumer Testing: Blind Tastings and Behavioural Research in Asian Cuisines – Taste Matters.

Author's comments

The material sounds pragmatic, "engineering" optimism: microalgae are not exotic for the sake of hype, but a real constructor for protein products, if you look at the task through the eyes of a materials scientist. The key is not just to grow biomass with 60-70% protein, but to teach protein fractions to assemble into a "meat" microstructure and at the same time maintain taste, juiciness and price. Therefore, the bet is on the duet of microalgae + soy: the former has protein density and compact production, the latter has proven texturability and a "soft" taste profile.

The author emphasizes several important, often “unspoken” things:

• Texture and sensory are more important than slogans. A "green" footprint is a plus, but people will buy what is pleasant to chew and tasty to eat. Hence the emphasis on self-assembly of proteins, fiber, and fat/juice retention.
• Functions are more important than taxonomy. It is not so important "what kind of algae" as what functional properties (solubility, gelation, emulsification) the isolated protein fraction provides after processing.
• The blend is not a compromise, but a strategy. The mixture of algae and soy proteins helps to close three tasks at once: amino acid profile, technological effectiveness and neutralization of "marine" notes.
• Urban production logic. For Singapore and megacities, the key is "protein/m²" and seasonal independence: closed reactors, short supply chains, batch stability.
• Economy and energy are the filter of reality. Cheap dehydration/bleaching and scaling of mini-workshops are bottlenecks; without them, ecology and price can "evaporate" at the processing stage.
• Regulation and trust. "Novel food" is standards, allergens, labeling and consumer tests, and for local cuisines (not just "burger format").

What, according to the author, needs to happen next for “seaweed meat” to move from demonstrations to a mass product:

• Standardize protein concentrates (batch to batch by functional metrics, not just by % protein).
• Energy-efficiently solve the "dirty" steps - water separation, deodorization/bleaching without losing nutrition.
• Launch mini production chains in the city: from reactors to pilot extrusion lines and cold logistics.
• Link recipes to the context of the cuisine (Asia/Europe): aromas, fats, spices - for real behavioral tests.
• Honestly calculate LCA (carbon/water/energy) for real scales, not lab grams.

The main message: alternative protein is not a single “super-ingredient,” but a combination of materials science and food solutions. Microalgae provide compactness and protein density, soy provides reliable “reinforcement” of texture, and competent engineering turns this into a product that you want to eat a second time.

Conclusion

Microalgae are not a futuristic fantasy, but a tech platform for cities where land is scarce and protein is needed. The work of Guldin and colleagues shows that if you control the self-assembly and texture of proteins, the "green" concentrate really turns into a "meat" product - and this logically fits into Singapore's 30x30 food sustainability strategy. Then comes the long-distance run: aroma, cost, standards and consumer love.

Source: Christine Ro. Raw ingredients: turning algal protein into mock meat. Nature, August 18, 2025; interview with S. Guldin (TUM/TUMCREATE, Proteins4Singapore). Additional context: 30×30 goals and materials about Proteins4Singapore. doi: https://doi.org/10.1038/d41586-025-02622-7