A “blue-green” food industry is underway, aiming to create a sustainable future for both nutrition and the environment.

The next big discovery in sustainable protein is not being developed in a laboratory, nor does it grow in a field – it gently sways in the ocean. Scientists have managed to solve the puzzle of extracting protein from seaweed, a breakthrough that could change our eating habits.

Seaweed grows on rocks in calm waters or floats freely on the surface, offering many advantages as a protein source. Unlike land crops, it does not require irrigation, fertilizers, or pesticides, and in addition to proteins, it also contains other valuable nutrients, such as vitamin B12 and omega-3 fatty acids. All of these make it an extremely interesting source of nutrients.

The innovation, developed by researchers at Chalmers University of Technology in Sweden and described in Food Chemistry, addresses a fundamental challenge: While seaweed naturally contains valuable proteins, accessing them has been extremely difficult due to the plant’s complex composition. Some proteins are water-soluble, while others are bound to fats in the cell membranes, making their extraction particularly challenging.

The research team, led by João P. Trigo, developed a two-stage extraction process that targets both the water-soluble and the more elusive lipid-soluble membrane proteins of seaweed. A surfactant (Triton X-114) opens the cell membranes of the seaweed, allowing access to the lipid-soluble proteins. Next, the researchers use an alkaline solution to extract the proteins, applying acidification so the proteins aggregate and can be separated from the water.

This new method proved to be three times more effective, possibly bringing closer the day when seaweed will become a viable source of protein for human consumption. The extracted protein takes the form of dark green powder, a versatile form that could be used in various food applications. The protein contains all the essential amino acids and higher levels of lysine compared to traditional extraction methods. Additionally, beneficial omega-3 and omega-6 fatty acids are co-extracted, enhancing the nutritional value of the final product.

In parallel with this research, the scientists at Chalmers are collaborating with the University of Gothenburg to increase the protein content of the seaweed. They found that this can be achieved by cultivating the seaweed in processed water, a process that also recycles nutrients that would otherwise be lost.

This development comes at a crucial time, as global demand for protein increases and traditional sources of plant-based and animal-based proteins face growing pressure. Cultivating seaweed offers a unique solution, not only providing valuable protein but also benefiting marine environments and protecting coastlines.

It should be noted that the current method uses a laboratory-grade surfactant, which is not yet food-safe, but the research is a significant step towards the commercial use of seaweed protein extraction. The researchers are already working to solve this issue.

“Humanity will need to utilize many more protein sources than we have at our disposal today to meet the demands of sustainability and nutrition,” says Professor Ingrid Undeland, coordinator of the CirkAlg program. “Seaweed is a good addition to many of the products already on the market. We need all of these solutions, which until now have been overlooked.”

In the future, the goal of the researchers is to utilize all components of the seaweed, as part of efforts to create a “blue-green” food industry where protein sources extend beyond traditional options.