Could Spirulina be the next super-nutraceutical to be widely grown in indoor vertical farms?

EatThis Functional Food

Image above: Algae production using a geothermal energy source. Image credit: Algaennovation, Iceland.

Who fancies some blue food? Really? 

The theory of food colour confusion may originate from us being strongly aroused by foods on the red spectrum. Research published in Nature recently showed that we are more attracted to red coloured foods as they appear to signal better nutrition with higher calories in comparison to blue or green foods. Trichromatic vision evolved in humans as a response to improve foraging and may explain why we rely more on sight than scent when locating the most nutritious foods and fruits that are ripe and ready to eat. This is surprising to us as ‘leafy green’ farmers when we readily assume a green colour relates to health but the Nature study was more assigned to calorific colour arousal.

Although our brains may not easily accept the blue colour as natural, our bodies will probably thank us if we do as blue-green algae also known as cyanobacteria has some of the best health benefits.

Superfoods: Yogurt with blue Spirulina, Scottish Damsens, Blueberries and Sloes.

One particular cyanobacteria has been studied extensively over the years

Spirulina grows naturally in alkaline waters and was recognised and farmed by ancient civilisations for its medicinal qualities. The Aztecs of Mexico have a long historical relationship with Spirulina. They farmed Spirulina in large lakes, then harvested and air dried the algae to form a hard edible ‘cake’. This was often mixed with other foods and used as an energy source as these ancient people recognised it as an important functional food. 

Massive health benefits that many people have still to discover

People who move beyond the colour tend to use blue-green algae for supercharging the immune system, controlling muscle spasms, detoxing heavy metals, eliminating candida, improving memory and increasing energy levels to improve exercise performance. It may also lower cholesterol and blood sugar, acting to prevent heart disease, heal wounds and improve digestion. Pretty impressive qualities for this single celled life form billions of years old. 

There are two main species of the blue green algae Spirulina, Arthrospira platensis and Arthrospira maxima. 

As the image demonstrates, they are made up of single cells containing chlorophyll filled vesicles that react to light and photosynthesize like plants. Cultivation of commercial algae usually starts the life cycle in lab culture tubes, doubling quickly under controlled conditions. This helps to eliminate contaminants. Spirulina is the largest single celled blue green algae and it forms spirals visible to the human eye which bunch together to allow a quick harvest and is now cultivated worldwide as a nutritional supplement. 

Spirulina is high in iron, calcium, magnesium, copper, beta-carotene and B-vitamins.

Apart from the high content of protein, Spirulina contains B vitamins, particularly B12 and provitamin A (β-carotenes), and minerals, especially iron. It is also rich in phenolic acids, tocopherols and γ-linolenic acid. Spirulina does not have a cellulose cell wall so it is more easily digested. Most people selling dried Spirulina suggest 1-8g per day to boost the immune system but be careful as too much can have negative effects so it’s best to start with the lowest dose

Some suggest Spirulina has the power to tackle world wide problems like malnutrition. The UN and WHO recommend Spirulina for it’s extremely high nutritional value and sustainability.  It has even been called the ‘world’s most sustainable food’ with the potential to end world hunger. The Pole Pole Foundation in the Congo were finalists in the Earthshot Prize recently. They are leading the way to teach communities in developing countries how to grow Spirulina as a supplement to prevent childhood malnutrition.

Could Spirulina be an alternative vegan protein source?

Would you drink blue milk? 

Many vegans are looking for alternative sources of protein. Spirulina might even be a protein source of the future and a substitute for cow’s milk.  Spirulina platensis stands out for being one of the richest protein sources of microbial origin having similar protein levels when compared to meat and soybeans.

Not to be confused with regular green Spirulina in its basic form, blue Spirulina is an extract of the active ingredient phycocyanin in its purest form. This concentrates the dried extract with higher levels of antioxidants without so much of the fishy taste of fresh Spirulina. 

But if you don’t mind using fresh Spirulina (it’s fishy so it’s much better to mix with stronger flavours) it will provide protein that is quickly and easily absorbed in the body compared to animal proteins which is a bonus as it contains many essential amino acids that the body cannot synthesize alone and are essential for tissue renewal.

Antioxidant and Anti-inflammatory

Fresh Spirulina is high in antioxidants, especially phycocyanin, the pigment which causes the blue green colour. Phycocyanin can promote blood cell regeneration, improve lymphocyte activity and improve the lymphatic system. Studies have shown this antioxidant scavenges and fights the free radicals that cause oxidative damage.

Spirulina is known to be alkalizing to the body which boosts beneficial microflora in the gut. Liver function is improved and this greatly increases detoxification levels in the body. Fresh Spirulina contains chlorophyll and phycocyanin both of which help to remove toxins such as heavy metals and other pollutants from the blood. One remarkable study in children who lived close to Chernobyl after the nuclear disaster in 1986 found that giving them a small 5g dose of Spirulina a day could reduce radionuclide rates by half in less than two months. 

Spirulina has Cancer fighting benefits 

Spirulina has been hailed as an anticancer superfood, but reading further into peer reviewed literature is important as there are some extrapolated and conflicting reports from doing a simple google search. So here we only present peer reviewed data. From our research low dose Spirulina has anti-proliferation effects on stomach cancer cells, human leukaemia cells and B lymphoma cells, inhibiting carcinogenesis. 

Eating Spirulina daily may lead to increased energy levels  

Fresh Spirulina is particularly good for energy owing to its high nutrient density. Since the algae has no cell wall to break down, digestion of all those nutrients is fast and efficient. It can make a difference to energy levels quickly after consumption. Fresh Spirulina contains constituents such as polysaccharides (Rhamnose and Glycogen) and essential fats that are absorbed easily by cells and theoretically aid energy release. More studies are needed to be truly conclusive though but with low toxicity levels in the body, it’s well worth your own trials. 

Spirulina enhances energy performance because it unlocks sugar from our cells. If you are suffering from memory loss, this bacteria added daily to your routine appears to have significant effects. It does this by protecting the brain from free-radical damage by increasing the activity of two enzymes: catalase and glutathione peroxidase, which fight free radicals and make the brain more resistant to aging.

But It’s not all good news 

Spirulina may exacerbate autoimmune reactions in some people who are susceptible. As such it may worsen symptoms of multiple sclerosis, lupus, rheumatoid arthritis and other conditions linked to overactive immune systems. It’s also not recommended for pregnant women or children or people on blood thinners like warfarin. Be cautious where you purchase Spirulina, as it may be contaminated if not bought from a quality source, leading to additional side effects.

Bioavailability: Should it be dried or is live culture better? 

Image credit: Ecoduna, Austria 

If you search for Spirulina online you are mainly going to encounter powdered products. There is nothing wrong with these as most research was conducted on using powdered forms which still showed positive results. However some reports suggest fresh Spirulina has up to 95% bioavailability. This means that 95% of the nutrients including essential amino acids, all the B vitamins and antioxidants are absorbed straight into your bloodstream increasing potency by 45% compared with powder. 

How difficult is it to cultivate and commercialize?

Spirulina cultivation requires sufficient aeration, agitation and proper light intensity for enhanced biomass yield, cell productivity, specific growth rate and protein content. Biomass yield has the potential to reach up to 12g/l biomass in a closed reactor system. Urea seems to be a promising alternative source of low-cost nitrogen for Spirulina cultures and addition of mechanised aeration will significantly increase yields. 

Spirulina vats in a hothouse, Mexico

But what about algal blooms? Are they the same Cyanobacteria?

Spirulina itself is non toxic but other forms of blue green algae including Aphanizomenon flos-aquae, grown and harvested in the wild, is often contaminated and leads to toxic conditions when out of control. 

Blue-green algae occurs naturally in lochs, ponds, reservoirs, rivers and the sea. This summer in Scotland it became a real issue. When the conditions are right, blue green algae will create massive blooms so large they can be captured by satellite imaging from space. Blooms are accelerated by leaching of fertilisers, with nitrogen and phosphorus runoff into the water course which becomes detrimental to other life forms by blocking oxygen and releasing toxic microcystins.

So it’s a logical step to grow these in a controlled environment and if market conditions continue to accelerate consumer demand for functional foods then growing these super algae in CEA could be highly profitable for farmers.

Image credit: Earthrise

The largest US producer of Spirulina is based in California and they produce on an open 108 acre site, exporting to over 20 countries worldwide. There are disadvantages of open ponds as they do not reach high biomass productivity due to the difficulty of maintaining the optimum temperature and so they are restricted to tropical and subtropical regions. This is mitigated to some extent with large paddles constantly moving the ponds.

Despite this hefty competition, CEA could be the perfect vehicle for growing a crop that has incredible health properties, sequesters CO2 and can be grown in tubing to eliminate contamination. With LED lights and agitation, enhanced yields could be harvested year round. 

This could be particularly useful between the shoulder winter months to increase profits and farm skills where wholesale prices have the potential to return profits of up to $15/Kg . A rough estimate of 12g/L biomass can be achieved with a photobioreactor system incorporating PPFD 166 μmol photons m−2 s−1 with potential doubling every 2-6 days depending on the algal species chosen. Based on this, and assuming you harvest 50% at each doubling time, a microfarm running 100L tanks could harvest 0.6Kg every 2 days, giving a total annual yield of 106.2Kg and a potential maximum annual return of $1593.  Scaling up production will make more economic sense. Optimizing and automating additional technology (LED lighting, CO2 enhancement and state of the art infrastructure as seen with Algaennovation) may boost production but this must be carefully managed to balance a return on investment.

Image credit: Algaennovation

Learning and applying new ideas – food, fuel & carbon trap

Image courtesy of Energy Futures living laboratory project, Lille France

We like to get people talking about the future diversity of CEA. This helps drive innovation and creates wider jobs and skills. At the same time we aim to help you better understand the science and health prospects of plants that could be grown in CEA.

Of all the ideas out there, maybe our favourite is the idea of an algae curtain. Glow in the dark tubes of algae obscure prying eyes from your space while producing your own superfood or fuel. 

Could plants literally fuel plants in a completely carbon neutral circular economy? Biodiesel produced using algae contains no sulfur, is non-toxic and highly biodegradable. This could have potential in offsetting CEA energy outputs and algae fuel cells could make home farms more economically sustainable in the future. There are so many applications for algae, some are even using it to extract CO2 from brewing. 

Whatever reason you have for growing Spirulina and others (chlorella) there is no doubt about this being classed as a superfood. 

Closer to home we like the way CEA farmers are looking to diversify their product range and kudos to On the Grow farms in Rockwall, Texas, growing spirulina alongside their microgreens. They grow in demijohn bottles adjusting the salinity to 2 and pH 10.5-11, harvesting and topping up fresh water every day. In order to maintain high pH and avoid fluctuations, high amounts of sodium bicarbonate must always be included in the culture medium to buffer the solution. The water needs aeration and temperature needs to be tightly regulated to 80F. LED lights will speed up production and your farm will literally bloom.

Image credit: On The Grow Farms, Texas

Spirulina first rose to fame as a potential space food. Maybe in space our brains are altered by gravity to be more accepting of blue food. Or maybe we will discover a whole new superfood bacterial species on Mars or deep in the ocean.

So who’s got a spare shelf in their vertical farm for this blue superfood and space age protein milk shake? 

Janet Colston PhD is pharmacologist with an interest in growing ‘functional’ foods that have additional phytonutrients and display medicinal qualities that are beneficial to human health. She grows these using a range of techniques including plant tissue micropropagation and controlled environmental agriculture to ensure the highest quality control.

You can follow The Functional Plant Company on Instagram

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