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In recent years, seaweed has drawn attention due to its potential as an alternative protein source. Noteworthy progress has also been made in the creation of seaweed products that meet the specifications of animal product replacement developers, such as Umaro’s red seaweed bacon.
Algae can be cultivated in numerous different settings, from a large "pool" to precisely controlled bioreactors. The quality of raw materials is key to the production of consistently premium food products and, in this respect, not all seaweed protein is created equal. Consequently, manufacturers need to choose a seaweed protein based on its suitability for use and competence as a superior protein.
The primary focus of this article, therefore, is to give an overview of seaweed protein, its potential as a premium protein source, quality and functionality benchmarks, and some key considerations on how to make commercially viable seaweed products.
Seaweed is a term used to describe many different species of microalgae and macroalgae (marine plants). It’s been estimated that there are between 30,000 to more than 1 million species, with an abundance left to be discovered.
Seaweed species range in color, taste, nutritional content, and size (from microscopic phytoplankton to giant kelp reaching heights of more than 100 feet).
Despite their variability, cultivating seaweed offers numerous advantages. For example, it does not compete with terrestrial agriculture, many species do not require fresh water, and the production process sequesters carbon.
Seaweed could also contribute to future global food security due to its potential as a source of protein and other desirable nutrients.
Seaweed protein levels can vary significantly depending on the species and cultivation conditions.
Both microalgae and macroalgae hold potential, although the former tend to contain higher levels of dry-weight protein. For example, microalgae spirulina (an already popular seaweed protein extract that has made great strides in various food market sectors) contains up to 70% dry-weight protein. On the other hand, the highest documented level of protein in macroalgae is only 47%, found in Porphyra.
While this distinction may appear to put macroalgae at a disadvantage compared to microalgae, after harvesting, it does in fact yield higher biomass compared to microalgae. It is also currently more cost-efficient when taking the concentration process into consideration.
To achieve commercial viability, it’s recommended to screen microalgae with at least 50% protein content. Not only will this enable food innovators to compete with existing protein sources on the market, but it will also reduce downstream processing costs.
To produce products that will be commercially viable and competitive in terms of price, efficiency, quality, and functionality compared to other animal-derived and alternative proteins, seaweed protein needs to perform on a similar or greater level.
A number of indicators can be used to assess the quality of seaweed protein, such as the amino acid profile, bioavailability and digestibility scores, and regulatory processes to ensure consumer safety.
While the choice of algal strain is undoubtedly important when sourcing a premium seaweed protein, the quality can also be influenced by the cell culture media, growth conditions, and upstream and downstream processing.
We’ll now review some of the methods devised to assess protein quality while demonstrating how seaweed protein performs in relation to current industry standards.
The Essential Amino Acid Index (EAAI) compares the ratios of essential amino acids in relation to the profile of whole egg protein, which acts as a highly nutritive reference standard. This index enables the integration of all of the essential amino acids into one calculation, allowing for straightforward comparability between different protein sources.
In the majority of seaweed studied, approximately half of the amino acids present are essential amino acids (EAAs), similar to the profile of egg protein. Nevertheless, manufacturers should optimize seaweed production systems to ensure the amino acid profile of their chosen algal strain meets FAO/WHO/UNU recommendations.
The EAA profile is not the only important measure of protein quality; the digestibility of seaweed proteins should also be prioritized.
There are currently two recognized evaluation methods for protein quality, Protein Digestibility Corrected Amino Acid Score (PDCAAS) and Digestible Indispensable Amino Acid Score (DIAAS).
The former has been recommended by the FAO since 1989 and works by comparing the amount of essential amino acids in a given food to a scoring pattern. It’s a well-recognized system that continues to have value today.
Nevertheless, over the past decade, this method has largely been replaced by the more accurate digestibility index, DIAAS. This index determines the ratio of digestible amino acid content compared to those of a reference pattern based on age-specific requirements.
So, where do seaweed proteins stand?
Current research has demonstrated that both macro and microalgae have low digestibility when consumed in their raw form. It’s therefore important to break the algal cell wall (cell disruption) to procure bioavailable and digestible seaweed protein, regardless of whether or not the entire biomass is being used to create the end product.
Having said that, PDCAAS and DIASS data are presently lacking for many algal proteins. Therefore, further investigation is required to assess the bioavailability and digestibility of processed seaweed proteins in order to assess their impact after human consumption.
Both macro and microalgae have the ability to accumulate heavy metals which, if consumed, can be toxic to humans. Therefore, manufacturers must assess toxicity when developing a production process for seaweed protein.
Safety concerns include microbial contamination, impure water usage, the presence of purine, and the use of toxin-producing seaweed strains. It is also important to consider potential food allergies since many algal strains do not boast a history of safe use.
In addition to conducting regulatory and safety tests throughout the production process, manufacturers must undergo novel food regulations before bringing their products to market.
If seaweed protein is to be accepted by consumers as an alternative to animal protein, manufacturers should also consider functionality. From the color of the end product to the taste, seaweed protein has to be palatable. Additional properties, such as emulsification and foaming (important for egg and dairy applications) or gelation and water-holding capacity (valuable for meat analogs), should also be explored.
Food innovators could also take advantage of seaweed’s many other beneficial properties. For example, the alginates present in brown seaweed could be used as hydrocolloid gels in products such as seaweed-based high-protein mayonnaise and salad dressings. And red seaweed exhibits remarkably umami flavors, which could prove valuable in the production of red meat analogs.
A Danish-based food-tech company specializing in the development, cultivation, production, and commercialization of functional and protein-rich ingredients from algae. Aliga Microalgae recently patented its white and chlorophyll-free Chlorella algae, which has a neutral flavor akin to soy and pea protein.
Based on the existing research, it’s evident that seaweed protein exhibits considerable potential as a premium protein source. The high levels of dry-weight protein coupled with favorable digestibility after processing places it in a good position in comparison to conventional plant and animal-derived proteins.
It is because of this potential that we expect to experience the uptake of seaweed protein in food manufacturing as a key plant-based trend over the coming years.
By selecting a strain that meets the aforementioned criteria on protein quality and safety, manufacturers can facilitate consistently superior end-products that compete as a viable alternative protein source.
Naturally, there are many other factors in addition to protein quality that one must consider when selecting an algal strain. Other desirable properties include high growth rates, pathogenic resistance, adaptability to climatic conditions, and conduciveness to low-cost harvesting and protein extraction.
Still unsure?
We can help you achieve clarity regarding the entire value chain for seaweed-based products, from specific support in selecting your algal strain and subsequent seaweed protein to developing your go-to-market strategy. Get in touch with Bright Green Partners today.
