Sustainable ingredients: how algae could help feed a growing population

03-03-23 / 10 min read

Red seaweed floating in crystal clear water

When it comes to sustainable ingredients, there’s been a growing conversation around algae and how it could help to feed an increasing population healthily and sustainably. Large-scale cultivation of algae has happened for a while now in the biofuel industry, but in more recent years algae’s potential as a sustainable food source for the future has also picked up pace.

Last year, the European Commission proposed a series of actions to “fully harness the potential of algae in Europe”. These include increasing consumer awareness and understanding of algae and algae-based products and their benefits and growing research and technological developments by funding SMEs and projects which work with the algae.

So, what are algae? The term refers to a large group of organisms that grow in a range of waters including fresh and saltwater. There are two varieties of algae which can be used by the food industry. The first, known as macroalgae, or seaweed, have been a staple part of the human diet for thousands of years in some parts of the world like Japan, China, and Korea – featuring in sushi rolls, soups and salads. Some of these include wakame and kombu which are brown seaweeds, sea lettuce and umibudo which are green seaweeds, and nori and Irish moss which are red seaweeds. The other type is microalgae, which are microscopic single cells that take in carbon dioxide, nutrients and water and turn them into proteins, fats, and carbohydrates through photosynthesis. Some edible microalgae varieties include chlorella, spirulina, tetraselmis and nannochloropsi. While we can’t see microalgae with the naked eye, they are primary producers in the food chain and have been essential to the survival of the ecosystem for centuries.

What makes algae sustainable?

The main reason algae are deemed to be sustainable is that they don’t require arable land to grow. They nourish themselves through photosynthesis and don’t require much to survive besides an aquatic environment, seawater/freshwater temperatures, plenty of light, and CO2 – which also makes them natural sequesters of carbon. Dr Craig Rose (aka Doctor Seaweed), Founder of organic seaweed supplier Seaweed & Co. explains: “Algae, in terms of seaweeds, are an inherently sustainable food source as they generally do not require land, freshwater or fertilisers to grow – which are key factors that limit sustainability of terrestrial plants and animal production.”

Andrew Spicer is the Chief Innovation Officer, Chair and Founder of Algenuity Ingredients, which develops a range of Chlorella-based microalgae ingredients agrees: “When compared to animal sources of nutrition all algae are significantly more sustainable in terms of carbon footprint, land use and water use.” There are even some types of microalgae that can grow without the need for sunlight by using glucose for energy through a process of microbial fermentation, he explains. Such a process can often result in greater growth: “When microalgae are grown by fermentation, much higher yields can be achieved, in the order of 50 to 200x higher per volume of water and area of land as compared to outdoor cultivation.”

While algae are naturally found in fresh and seawater spaces, they aren’t tied to these areas either. As Andy Zynga, CEO at EIT Food explains: “Algae can also be farmed in places where many other food ingredients can’t be grown, from open seas to rooftops and industrial areas. This flexibility means that as algae production becomes more widespread, supply chains can be shortened to keep production closer to processing and retail sites. This has the added benefit of reducing the emissions from transporting products to market, as well as increase product shelf life and reduce food loss and waste.”

The nutritional profile of algae

Algae are incredibly good for us. They are nutrient-rich and contain a lot of vitamins and minerals such as vitamin K, iron, zinc, and magnesium. They are also a primary source of essential amino acids such as omega-3 – all the fish we currently consume get their omega-3 from consuming algae. They also offer a source of vitamins and minerals that many humans don’t include enough of in their diets such as iodine, says Dr Rose. “The breadth of nutrients in algae are unparalleled in land-plants”, he says. “The key nutrient in our PureSea seaweed, iodine, is severely lacking in the UK and European wide diets, with between 70-84% of people not getting enough, and around 2 billion people globally.”

Some types of microalgae like Chlorella are also known to be complete sources of protein, says Spicer. “The protein quality is high and can support muscle metabolism and growth”, he explains. They also contain a wide array of plant fibres, polyamines, and antioxidants that have several health benefits such as being good for gut heart health, and cognitive function to name a few. Spicer explains: “Some microalgae including Chlorella have been described as ‘superfoods’ mostly because they are strong nutritionally regarding macro and micronutrients but also because they include various other plant compounds that have associations with health and well-being.”

While there are plenty of varieties of algae, they aren’t all suitable for consumption. As Spicer notes: “While there are potentially hundreds of thousands of different species of algae on the planet, only a small number are currently approved as food ingredients and eaten in various forms.”

As well as having great nutritional value, both micro and macroalgae are also known for having a distinctive taste of the sea, which can be described as an earthy or umami flavour. Most types of micro and macroalgae also have a strong green colour which is difficult to omit during production. Both the strong taste and colour of algae have proven to be a barrier in the past when it comes to making it a universal ingredient for food and drink products, as it has limited what it can be added to.

Food applications of algae

Despite the challenges that come with using algae as an ingredient, an array of innovation in the food industry has meant that algae have been able to become more versatile, and easier to add to a variety of food and drink products and supplements.

According to Dr Rose, “Seaweed can be added to anything (and I would argue to everything!) in the sense it offers a huge amount of essential nutrition for a very small inclusion”. While a variety of seaweed has existed on supermarket shelves for years, they have also more recently become available in the form of supplements and as an added ingredient to a variety of food and drink. Seaweed & Co.’s PureSea ingredients made from Hebridean Ascophyllum seaweed for instance are being developed to be suitable for use in a range of product applications. As Dr Rose explains, the ingredients are suitable for enriching and develop the flavour of plant-based fish. Despite having a naturally strong sea-like flavour, the company has also been able to develop a flavourless version of the ingredient which is still seaweed-based and makes it suitable for use in sweet food and drink products.

Algenuity Ingredients has also developed microalgae ingredients which are both neutral in flavour and colour with its white non-GMO Chlorella varieties, created using microbial fermentation. During the production process, Algenuity’s experts can select specific traits for the white Chlorella, such as colour, macronutrient composition, digestibility, and productivity. “All of these are based on the natural variation that can be achieved within the genetics of the organism. By creating white Chlorella varieties, we have established a food and beverage ingredient that is neutral and colour and taste while retaining the nutritional benefits,” says Spicer. “By removing the barrier associated with the dominant green colour and very poor sensory properties, we have developed an ingredient that can now be used at significantly higher rates of incorporation in foods and beverages to deliver simpler, tasty, healthier foods”. The versatility of the ingredient means it can replace dairy and egg-based ingredients in a range of applications and can also be used to complement and improve NPD in plant-based fish and seafood.

Another company that has created its own white Chlorella ingredient is Aliga Microalgae, which spent over two years researching new ways to naturally remove the gene that produces chlorophyll in its Chlorella. Overcoming such a hurdle has enabled the company to develop a “clean-label whole food ingredient” which can be used in a variety of food applications, the company’s co-founder David Erlandsson explains. “[The ingredient] is an excellent complement to soy and pea protein in a broad variety of plant-based food formulations, such as fish, seafood and chicken analogues. For example, by blending just a small percentage of our white Chlorella with pea isolate in a High Moisture Extrusion, the texture and fibre formation is greatly improved, and a juicer mouthfeel is achieved due to the algae’s water absorption capabilities.”

Barriers facing the sustainable production of algae

While boosting the use of algae in food products would be incredibly beneficial for our health, the sustainable nature of algae production very much depends on how it is farmed. As Dr Rose explains: “There are instances where intensive algae farming will have fertilisers added to the seawater, which can cause wider ecological damage.” When too much fertilizer enters the sea, this can cause an abundance in algae growth, resulting in lower oxygen levels in the surface waters, which in turn means fish and other sea species are unable to survive.

There are alternatives to intensive farming such as wild harvesting, but these also come with difficulties, says Dr Rose: “Equally, wild harvesting still offers massive potential as a supply source, and can be sustainable, but some species are not well suited to this and can be over harvested quite quickly as demand grows.” Better management of the farming sites could help to overcome these barriers in algae farming, he says, stressing that these are “simple bad practices [which] in no way hold back the potential of algae food and nutrition opportunities.”

The development of microalgae ingredients also isn’t a carbon neutral process, according to Spicer: “There is a lot of energy needed to move (by mixing or pumping) the large volume of liquid in which microalgae grow and a large energy need required to dewater and dry the microalgae. There are exceptions to this rule but, generally, microalgae production outdoors is not carbon neutral or carbon negative based upon the energy needed in the production and harvesting.”

Cultivating microalgae through microbial fermentation, which how Algenuity grows its Chlorella, isn’t emissions-free either, he says. “While the full production process is not carbon neutral or negative, similar to mycoprotein, we are vastly better than animal sources of nutrition in terms of carbon footprint, land and water usage and we are on a mission to improve that position further.”

The future of algae

While algae could feed more people nutritiously and more sustainably, much work and support is still needed to help the sector fulfil its potential. As Zynga explains: “Algae is an emerging sector, so financial support is crucial to ensure that growth conditions are optimised for sustainability as we accelerate and scale production.

“Innovation will play a key role in improving and scaling production systems,” he continues, “as well as training professional technicians on common problems and how to mitigate them. Offering education, training and incentives for farmers and producers can also help to ensure that algae continue to be produced in a way that minimises environmental impact.”

While financial support can help to improve technology in the sector and make it more sustainable, if the world is to reap algae’s benefits, the gap around consumer’s understanding of its nutritional and environmental values needs to be filled. According to Zynga, the EIT Food Citizen Participation Forum study found that just 3% of those surveyed knew that algae sequester carbon dioxide. Educating the public around the many benefits of algae is essential, he says, as is involving consumers in the co-creation of new algae-based products, which can help to boost interest and demand in such goods once they launch on the market.

The future potential of algae is promising, thanks to the ever-growing innovation in the sector as well as a growing interest from EU leaders, which will provide some of the financial support this area needs. Developing consumer knowledge and demand for the product, as well as new methods for making algae cultivation more sustainable is now the next crucial step to making it a staple sustainable ingredient in the food industry.