Not just plants: algae- and fungi-based proteins

Nowadays, research in alternative proteins is becoming increasingly crucial in order to develop healthy, nutritious and sustainable foods. When people talk about producing alternative proteins, they are referring to ethically and environmentally sustainable processes, which may include innovative extraction methods through fermentation or cell culture technologies. Plant-based protein sources such as soy, pea and legumes are already widely available commercially in the form of alternatives to dairy and meat. With the world population expected to grow to 8.5 billion by 2030, the market of new alternative protein sources to animal protein will eventually become a requirement. Therefore, different matrices, such as fungi and algae, must also be considered.

Proteins derived from the cultivation of fungi and algae are often obtained through fermentation and cell culture processes in bioreactors. These technologies have several advantages, starting from being unaffected by seasonal variations to not using arable land and potable water for growth (an extensive study here).

Algae as a protein source

Algae are a heterogeneous group of aquatic plants, and may be divided into microalgae and macroalgae. In Asian countries, consumption of macroalgae, such as the better-known Nori or Wakame seaweed, is common as part of culinary tradition. According to the article, microalgae have been associated in the past with biofuel production as an alternative and sustainable energy source due to their potential to absorb CO2 from the atmosphere and use sunlight as an energy source. However, high costs remain a limitation in making biofuel production from microalgae competitive. According to the species, microalgae can still prove to be an interesting food ingredient, as they are rich in carbohydrates, proteins, lipids and bioactive compounds.

The global market for algae protein was worth $3.15 billion in 2021, with a growth rate of 8.4% from 2022 to 2030, according to Gran View Research’s report. The segment has grown as a result of the COVID-19 pandemic, from the combination of several factors such as the rise of the vegan population and increased consumer awareness of the benefits in adopting a healthier food lifestyle.

In food, algae are commonly known for their use as a gelling, thickening, and stabilizing agent, and are cultivated worldwide as a source of carrageenan, agar agar, and alginates. They are also used in dietary supplements, as the main application segment in the North American market, due to the growth of fitness-oriented consumers in the United States, Canada, and Mexico.

Then, cyanobacteria, also sometimes and improperly called “microalgae” or blue algae, should be distinguished from microalgae, although they are prokaryotic organisms, thus much simpler and structurally different from microalgae. The latter are eukaryotic organisms like all plants and even ourselves. Cyanobacteria are also the subject of interest as an alternative source of protein.

Currently, proteins from algae are not yet competitive with plant proteins derived from field crops in terms of process cost scalability. However, several startups are looking at algae as an innovative protein source given their fast-growing ability and attractive nutritional properties, considered as superfoods due to their high concentration of protein, vitamins, amino acids, omega-3 and other essential fatty acids.

Fungi as a protein source

According to a report, the fungal protein market is expected to grow at a CAGR of 7.6% from 2022 to 2029, reaching $397.5 million. According to type, the fungal protein market is divided into yeast protein, fusarium venenatum (mycoprotein), and fungi (macro fungi).

The quality of protein obtained from fungi depends on several intrinsic and extrinsic factors, such as the choice of fungal strain, production system, culture media, nutrients provided, and the species used. The most widely used fungal protein for human consumption is the one from the mycelium, known as mycoprotein, discovered in the 1960s, that after 16 years of strict testing by the Ministry of Agriculture, Fisheries and Food of several countries was used to develop the first Quorn™ brand meat alternative product by Marlow Foods.

According to this study, the texture of mycoprotein from fusarium is similar to meat, and suitable for preparing alternatives to burgers and nuggets.

Yeast-derived proteins, on the other hand, are credited with nutritional benefits, and with enriching the flavor of the final product, and several start-ups are currently exploring this protein matrix.

Barriers to algae and fungal protein consumption

For fungi- and algae-derived proteins to compete with existing protein sources, the nutritional profile, digestibility, and functionality of these proteins would need to be equal to or better than the proteins already used in marketed products. This requires that new ingredients produced from algae and fungi meet certain criteria requested by the food industry: light color, neutral taste, high protein content, good amino acid composition and nutritional profile, and high bioavailability and digestibility. In addition to this, the production of proteins from algae and mushrooms is still limited by technological barriers, because of production costs, consumer acceptability, and regulations. Additionally, issues related to their allergenicity also need to be more explored, including proceeding to increase consumer awareness of protein sources other than those known, or not consumed in one’s regional diet.