Taking the pulse of CEA protein farming

“You should never hesitate to trade your cow for a handful of magic beans. “ Tom Robbins 

 Protein Replacement is a hot topic 

Nutrition and protein replacement in particular is a global health concern with implications for the future direction of the planet, not least because the tide could be turning on less sustainable types of food production. We have had some in CEA evangelizing about the power of CEA to feed us all in the future, but the reality is that we need all agricultural practices to work together where appropriate to create resilient sustainable supply food chains close to where people live. Given this opportunity we should consider how we assist the creation of new plant proteins in hi tech towers and glasshouses. It is with this thought in mind that we could be overlooking the potential of the fabaceae family which includes legumes (pulses are the edible dry seeds) that have sustained entire continents in times of need.

Amethyst Beans harvested after growing in CEA aeroponics under TLEDs. 

Getting real with alternative proteins 

We want to explore if pulses and specifically beans grown in CEA could provide complementary protein to that found traditionally in meat, dairy, fish and more recently, cellular meat (which is different from plant based burgers that incorporates soy, wheat, potato or mushroom protein). It should be noted that cellular meat also uses soy protein for scaffolds i.e. a lattice for cells to grow into 3D meat.

Let’s begin with an argument. Many in the medical community advocate a plant based diet to be wholly adequate to supply all the body’s protein requirements. Others argue that plants do not contain an adequate source of protein and that animal protein is essential for supplementing our diets. It could be time to challenge the assumption that ‘real men eat meat’. Whatever your stance, we do know that essential amino acids, thought to be less abundant in plant based diets, could in part be provided by chickpeas and soya beans, helping to supplement vegan or vegetarian diets. Make sure you add seeds, nuts, whole grains and lentils to ensure you get all nine essential amino acids. If you are worried about the lack of Vitamin B12 which cannot be provided by vegetables, try a source of shiitake mushrooms or nori seaweed in your diet. 

‘Beans are a great value for money meal and source of protein during the cost of living crisis’

While I’m old enough to have visions of Mel Brooks blazing saddles around the campfire, there are so many delicious recipes that create a heart warming meal from a range of pulses, legumes and lentils. Theoretically speaking it is better for the planet too if we consider biogenic methane production from a cow’s four stomach chambers versus our human gut should we consume more beans as our protein source in preference over animal protein. 

A trick to avoid gas: Eat more beans! Why? We often lack an enzyme called alpha-galactosidase produced by gut bacteria. This enzyme helps break down complex sugars that can, if not fully digested, cause excessive wind. As your body gets used to eating more beans (they act as a prebiotic to increase the good bacteria), more enzyme is produced in the gut to digest these carbohydrates. 

Bean based soup with chickpeas (in Spanish: Garbanzo beans), can add nutritional value to cheaper meals.

Beans are a staple in the diets of many underdeveloped countries, they taste good in meals and can in fact cost far less than meat based stews. They are also on a calorie ‘like for like’ basis much better for your health as well as being cheaper to produce. So the question then becomes, can we grow them close to where people live and in large enough quantities? 

Many people are unaware that chickpeas and other pulses contain components that when eaten as part of a balanced plant-rich diet, help prevent the development of diseases like diabetes and heart disease. These beans have a soluble fiber called raffinose, which is fermented in the colon by beneficial bacteria and has been shown to reduce inflammation. Chickpeas also contain a cholesterol like plant sterol called sitosterol that can trick the body into lowering blood cholesterol levels. The satiating effect of the high fiber and protein content of chickpeas may also help with weight management, another major factor in lifestyle disease progression.

The practicality of growing bean vines in VF like many other plants is dependent on the number of plants per square foot, breeding programmes to increase nodes (spectrum is likely to play an important function in early flowering) and compliant technology. Research into the economic efficiency for well designed CEA facilities (lights, oxygen, fertilizer) and indoor grow rooms should be considered versus higher energy outputs when considering new crops like beans. But, with quick production cycles and all year round growing potential, farms could easily be adapted much like other vines such as tomatoes and chillies to grow unique high protein legumes. They could even be tacked onto the side of existing horizontal structures with additional inter-canopy lighting. High production cycles are likely to determine profitability so modeling through trials is recommended.

Which ones to choose?

There are literally thousands of beans to choose from, with more than 40,000 known varieties of common bean. Here are just a few I have in my collection. 

  • Butter bean zlota saxa
  • French climbing blauhilde
  • Lima
  • Soya
  • Bush amethyst
  • Pole viola do assiago
  • Bambara (with seed coat) 
  • Pole blaue
  • Nonna Agnes

The Functional Plant Co in Scotland have been studying beans like Lima and ways to increase nodal development in CEA TC to produce high quality slips for continuous batch supply to plant factory’s.

Native American Beans are steeped in tradition 

Pole beans were a staple of Native Americans with more than 5000 known varieties spread worldwide. They have a long tradition in Native American culture including the Hopi tribe, whose Bean Clan is called Murzibusi. Such importance has been associated with beans, that some eastern tribes, like the Lenape, Shawnee and Iroquois actually have a ‘Bean Dance’ amongst their tribal dance traditions. Despite myths of their Mexican origins, Anasazi beans are thought to have been cultivated throughout generations of Southwestern Native American tribes. Today these beans are commonly used in many Latin American and Southwestern cooking turning pink once cooked, and are often used in refried bean recipes due to the sweetness. Remember it was the Indians that invented succotash with sweetcorn, lima and other mixed beans.

The Many Health benefits of beans 

Regular consumption of beans has been linked to disease prevention, including cancer, diabetes and heart disease.

Beans have a strong nutritional profile, marked by a high amount of iron, calcium and potassium per serving. As well as antifungal, antibacterial and antiviral properties, beans have a low glycemic index and are found to be high in lectins, a glucose-binder, with potential to avoid sugar spikes and naturally treat diabetes. If that wasn’t enough, the anti-inflammatory effects of these magical beans may also help you fight cancer.

The Color Purple 

The red/blue color of beans is due to a group of biological pigments called anthocyanins. This same group of compounds is also responsible for the rare blue pigments we see in nature.

Nonna Agnes Beans

An analysis of black beans showed most of the anthocyanins to be delphinidin, with lesser amounts of petunidin and malvidin. Delphinidin and malvidin are responsible for the blue color in various flowers. Petunidin is described as having a dark-red/purple color adding to greater health benefits.

Growing Beans in CEA

One of the most commonly used Native-American gardening techniques was ‘Three Sisters’, probably the first no till agriculture method on the continent. They planted corn, squash and bean seeds together. The beans provide nitrogen for the soil, the corn was a natural trellis and the squash a canopy to deter pests. 

The three sisters’ companion planting originated from native Indian farming of maize, beans and squash. 

Respectfully we’ve come a long way since then but as we look for protein replacements, beans are a natural choice to incorporate in CEA farms. 

From three sisters to one grandma, Nonna Agnes pole bean, one day post germination in high strength Gibberellin. 

The seeds of Nonna Agnes, a pearlest blue heirloom bean from you guessed it, Italy, germinate in a day with the hypocotyl peeking through the outer layer and reaching for light via tropic geotropism. The strength in beans is phenomenal as the large carbohydrate seed store forces the tap root downwards and shoots up. 

In normal soil production this can take several days longer than germinating in a controlled environment. Obviously the stronger the young plants, the more vigorous they are and with inter-canopy spectral LEDs it is possible to force flowering much earlier than in the field, with higher yields in a shorter time frame. 

These modest-looking legumes pack a mighty health punch. In addition to being an aforementioned protein source, they are an excellent source of fiber and act as a prebiotic, providing a nutrient source for beneficial bacteria and microorganisms that make up the gut biome in our digestive tracts. 

Let there be light amongst the vines 

If we are to grow these kinds of crops in CEA we need internodal spaced LEDS or a vertical hanging design to ensure efficient light intensity delivery to ripen pods. We already grow tomatoes with aerial LEDs so alternative vine crops like beans should be no different. Much will come down to modeling of economic returns. New technology emerging such as intercanopy lights to grow indoor vines will also add to biomass with higher yields and increased flowering during off peak times of the year. Choosing low light varieties that are bred with increased nodes will have a big impact and can help growers switch during tough times for high energy costs. Beans are a perfect example crop that have enough variety to experiment with low light varieties. From the beans I tested, Amethyst, Lima and Pole viola do assiago all produced flowers in two weeks with one TLED at 100umols/m2/s followed by pods in 2-4 weeks and a small harvest in 6-10 weeks. 

Faba beans flowering under Currents RB balanced LEDs in Scotland during autumn with average day temps 15-20 Celsius and night lows of 6-10 Celsius. 

Soybean pods filling up

Another member of the fabaceae is Bambara (Vigna subterranea (L.) Verdc.), an African equivalent of American peanuts growing from extended rhizomes. Also called the Congo groundnut, it is a fast growing plant, but needs warm temperatures over 150 days cultivation. Recent studies have found it to be very high in protein, providing all of the daily nutritional requirements of protein, carbohydrate, unsaturated fatty acids and essential minerals (magnesium, iron, zinc, and potassium). The waste greens can be fed to livestock adding to nutrition and sustainable agriculture. 

Unusual varieties like Bambara could be grown in locations previously unheard of, circumventing international supply chains and reducing carbon footprints. 

In Africa these beans are grown on small-scale subsistence farms by women, in a rotation with other crops like maize to fix nitrogen in the soil. Despite interest from international companies attracted to its high protein content, the supply chain for Bambara is not yet secure. An opportunity awaits CEA farmers with a warming climate. Perhaps even Texas could become a great location for a new crop. Germination can be slow because of the hard seed coat but once released from this we can use growth regulators to increase germination rates in addition to trialing micropropagation techniques to produce high quantity slips. 

Nonna Agnes Beans developing under Currents RB balanced TLEDs indoors in Scotland above.

Amethyst bean pods to the right and harvest below, the color change is evident in the last week of production.

How we preserve these crops for the future 

There is no doubt beans are cheap, sustainable (you can save some seeds for next year), easy to grow and packed full of protein with great health benefits suggesting they are not only good for the cook-book but also for the planet. Variety is key to the success of beans and we hope you look further afield (intentional pun) to incorporate these fine pearlest beans as a regular CEA crop.

Don’t know where to start? The Crop Trust in Svalbard, an archipelago off Norway holds a massive bank of beans, conserved from farmers across the world. Of course this is worthless if farmers don’t have access to or take the opportunity to grow these conserved varieties. You can only request samples from depositing genebanks. As the seed bank shows, the way forward is cooperativity between growers around the globe. Breeding of heirloom varieties as well as processing via partners and marketing sustainable protein replacement to consumers will encourage the FMCG industry to create healthy plant based protein products in the future.

Image credit: Crop Trust. Svalbard Seed Bank in Norway is our modern day ark. 

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.

Unless otherwise stated all images are courtesy of The Functional Plant Company and property of Urban Ag News.