Duckweed

As a species, we humans like to think we are several rungs up the evolutionary ladder from the fish. And in so many ways we are. Our contribution to science, space exploration, literature and the arts, not to mention engineering and medicine are definitely more advanced than theirs. We invent rovers that survive on the Martian landscape for 14 years, engineer semi-autonomous vehicles, and we develop 3-D printed transplant organs; fish merely swim, spawn, eat, and occasionally inspire movies like Finding Nemo. But aside from profiting Pixar, there is something that unites humans with our aquatic little friends, something both species have in common. And it is in the realm of the culinary arts. Although it goes without saying that a fish’s ultimate contribution to sushi is significantly more meaningful than that of its human counterpart, it is in the area of food that sustains both fish and humans that we are united. Moreover, it is in the apparent lack of regulatory oversight, dearth of cGMPs, and absence of HACCP protocols in the creation of a type of plant-based protein to feed both species that we have common ground. And in the relative disinterest on the part of the FDA. What are we talking about? Duckweed!

In health-conscious, foodie circles, there are several concepts that repeat so frequently as to become mantras. Terms like cold-pressed, organic extraction, wholefood-based, and green are now so ubiquitous as to be almost cliché, with the latter largely considered the Holy Grail of foodie marketing. And as we sit surveying the beverages of choice of our desk-bound co-workers, we do note that among the protein shakes and fancy ‘venti-iced-skinny-macchiato-with-sugar-free-syrup-an-extra-shot-light-ice-no-whip-TO-GO’ another few key terms are equally popular.(1) Concepts such as plant-based, hemp/pea protein, non-dairy, and allergen-free. Indeed plant proteins are all the rage these days as we’ve outlined in our previous articles, ‘Soylent, Joylent, Zoylent, and Biolent: Meal Replacements for the Zombie Apocalypse?’ and ‘High-Tech Hemp: How is This Humble Seed Moving Beyond its Hippie Heritage?,’ for so many reasons. Setting aside the already well-documented issues surrounding the production of animal-based proteins, the benefits to us as consumers of plant-based alternatives are usually evident: bio-sustainability; environmental conservation; the ability to bring clean, inexpensive, ethically-sound, and nutrient-dense food to those facing food insecurity – to name just the most obvious. But, analogous to animal-based proteins, not all plant-based alternatives are regarded as equally acceptable. As we already discussed in the piece ‘Edible Insects? There’s a New Kind of Crunch in Town,’ there can be a limit to what consumers will tolerate when it comes to the provenance of their protein. And, like grasshoppers, scorpions, or crickets, duckweed – aka lemna, aka ‘pond scum’ – may be just the other side of that line of acceptability.

Lemna. You will be forgiven for drawing a blank on the name.

A member of the duckweed family which includes wolffiella, spirodela, wolffia, and landoltia, lemna is also termed the ‘water lentil,’ due, we suspect, to its adorable lenticular flowering form. The plant has a tiny root but no internal structures, stem, or skin and is basically a tiny ‘photosynthesis factory,’ floating atop a body of water.(2) And its growth rate is nothing short of astonishing. With a dry weight yield of between 20 and 40 tons per year thanks to exponential growth which sees it doubling every 48 hours, lemna offers a complete protein profile of bio-available amino acids in addition to both Omega 3s, a healthy dose of fiber (15%), and a random scattering of vitamins and minerals. It grows naturally on every continent (except for polar regions) and holds the record for being one of the smallest flowering plants on the planet.

So where do we get our hands on this water lentil protein? Good question – and we’ll return to that shortly. But for the moment, the biggest excitement in the use of lemna is in aquaculture. For some time now, the consumer shift away from land-based sources of animal protein has been associated with an uptick in sales of fish products. But as we are increasingly aware, our demand on the oceans to provide us with clean, healthy protein simply outstrips its ability to do so and, using the same logic that created the environmental disaster that is the concentrated animal feed operation (CAFO), we are turning increasingly to aquaponics – the raising of fish in concentrated commercial operations. And although this may seem like a viable solution on first glance, fish farms bring with them a whole slew of challenges – environmentally, ethically, and in terms of fish and human health. One of the most intractable of these problems is, of course, the use of fishmeal to feed the piscine dwellers.

Feeding fish to fish?

Yes, in fact according to an article published by NPR, a recent study showed that a full 25% of wild caught fish are diverted from the human-bound food chain, destined instead to become fishmeal and fish oil.(3) Yet the 2017 study by researchers Tim Cashion, Frederic Le Manach, Dirk Zeller, and Daniel Pauly which appeared in Fish and Fisheries, a refereed academic journal published by Wiley, highlights the fact that most of these fish are human-grade catch such as herring and anchovies. And these fish, which traditionally appear on dinner plates of other nations, are considered ‘trash fish’ to the American consumer and are simply fed to other fish such as carp and tilapia. So not only are approximately 20 million tons of wild caught seafood diverted from the human dinner plate, but they are also fed to other sea creatures that are, in nature, vegetarian and/or filter feeders. Anyone else see a problem here?

So what if, instead of diverting such a major part of a wild catch away from the human consumer and toward farmed fish, we allowed carp, tilapia, and the like to maintain their non-carnivorous nature and fed them a plant-based protein instead? That’s precisely what a Florida-based company, Parabel, is hoping to achieve with its products Lemna Protein Concentrate (LPC) and Lemna Meal (LM) for the animal feed sectors. According to Parabel’s website, unprocessed lemna has long been an ingredient in poultry diets in Asia and Latin America and its elevated digestible amino acid concentration is especially well suited to the monogastric digestive system.(4) Equally, in ruminants such as cattle – with their multiple stomachs – and in horses, the low starch and sugar content allows for a slow release delivery of energy, and trials at the University of Minnesota have demonstrated that dairy cows given a LM supplement instead of alfalfa meal are actually more productive in terms of milk yield.(5)

But it is arguably in the area of farmed fish that the greatest results have been demonstrated. In head-to-head comparisons of LM with sunflower meal, canola meal, soybean meal, and fishmeal, LC was found to contain more essential amino acids and was, in the case of tilapia, more than 85% digestible. And analysis of the test subjects – tilapia and shrimp – showed comparable growth, whole body composition, and protein and energy retention to their accidentally carnivorous counterparts.

Lemna, it seems, might well be a better source of protein for commercially raised fish, returning the wild-caught creatures to the human food chain. But what if you’re not a fish eater and want to incorporate this apparent miracle food into your diet? Fortunately, once again, it seems like the lemna offers a plethora of possibilities.

…lemna also packs 400 times more protein than the pea. Still not impressed?

Located in the Californian town of San Marcos, Plantible Foods was established to grow organic lemna in low-impact, environmentally sensitive aqua farms. Sporting what is arguably the most adorable plant-milk-drinking photographer’s model, Plantible’s website claims their lemna crop to be 100 times more efficient in terms of protein delivery than soy.(6) Which is not a bad start. But attractive as that statistic is, it’s perhaps more interesting to note that lemna also packs 400 times more protein than the pea. Still not impressed? Let us give it one more shot: perhaps what really stands out in the data is that lemna – the company’s so-called ‘humble protein hero’ – is 50,000 times more effective as a protein delivery mechanism than beef. Fifty thousand times more protein delivery efficiency than what’s generally considered the gold standard of protein intake: beef. Attention bovine buddies – your days on our plates just might be numbered…

And then there are the ancillary issues around lemna as a source of protein. It is an inherently all-natural and organic product that’s also free of the top 8 major allergens. With little odor and a neutral taste and color, it’s versatile in terms of use in the manufacture of consumer packaged goods. Plantible foresees leveraging lemna’s nutritional flexibility to incorporate it into consumer-ready foodstuffs in multiple industry silos. Think of sports drinks and equally of meat or dairy alternatives, nutritious snack foods, and ready-to-drink meal replacers – all of these product types could, theoretically, make extensive use of this type of duckweed.

So might we start seeing it used in burger patties, energy bars, and such like?

If the success of the pre-seed funding round led by Unshackled Ventures, an ‘early stage fund for immigrant-founded start-ups based out of Silicon Valley,’ is anything to go by the answer is a resounding ‘Yes!’ Although the amount of funding awarded has remained a secret but is probably below Unshackled’s $500,000 threshold, it is considered sufficient to allow Plantible Foods to move forward in finalizing its extraction technology and to build relationships in the food science sector to commercialize the products. Impressed by Plantible’s ability to create ‘the world’s most sustainable, applicable, and simply best plant-based protein that can help feed the world, while not destroying the planet in the process,’ Unshackled Ventures, a ‘Day 0 funder,’ is on record as being ‘excited to add another socially and economically conscious investment to our portfolio [and to helping] them succeed faster in the US.’(7)

But there are still questions hanging over the duckweed miracle that lemna proposes itself to be. As we hinted at the top of the article, little is yet known about the nature of Current Good Manufacturing Practices (cGMPs) or the extent of Hazard Analysis and Critical Control Points (HACCP) prototcols that Plantible has in place for products that are intended to enter the human food chain. According to the company’s website, the production process for the lemna will be ‘transparent and traceable’ but further details are non-existent.(8) And as contamination control experts, you know we feel a lot more comfortable when such details exist, so we did some digging.

In November last year, Parabel – headquartered in Florida – received Food and Drug Administration recognition of its use of lemna as GRAS – Generally Recognized as Safe. As we already discussed, Parabel serves both the human food and animal feed markets, creating Lentein™ – a powder that can be baked into crackers or cereal bars or incorporated into sports drinks – and Lemna Protein Concentrate (LPC) and Lemna Meal (LM) for the animal feed sectors. In the GRAS notice for LENTEIN™ Complete and Degreened LENTEIN™ Complete as a nutritive ingredient in human food, it was noted:

‘Parabel Ltd. has critically evaluated the published and unpublished data and information summarized in the safety evaluation, and concludes that Parabel’s LENTEIN™ Complete (LC) and Degreened LENTEIN™ Complete (DGLC) – which are produced in accordance with FDA Good Manufacturing Practices requirements and which meet the appropriate food-grade product specifications as set forth in Section II.E.2 of the provided safety evaluation and as required by FDA regulation, 21 CFR 182.1[b][1] – are considered the be Generally Recognized As Safe when consumed as a nutritional ingredient in commercial food products to a maximum level of 201 grams per person per day.’(9)

For lemna to become a powerful alternative source of protein, robust contamination control processes must be devised..

So, phase one is complete: lemna has been granted GRAS status, and we can only hope that Parabel, Plantible, and any other players in the field build wisely on that designation. For lemna to become a powerful alternative source of protein, robust contamination control processes must be devised and exemplary quality assurance protocols should guide the manufacturing of products based on this nutritional powerhouse. Surpassing those of the current plant protein favorites – pea, hemp, and rice – the nutritional profile of lemna is such that its broader adoption into our diets may offer another solution to the increasingly significant challenge of feeding a growing world population. And it is one that offers a distinct advantage over animal-based, and even some plant-based, proteins: radical efficiency. Lemna tenders the possibility of reduced land and natural resource usage, minimized need for pesticide applications, and a significant decrease in energy use per calorie grown. Broader adoption will see the cost of production fall to increasingly competitive levels at the same time as large production upscaling holds no increased risk of environmental damage. And of course there’s the water issue. With water becoming a premium commodity in some areas of the world including here at home, the 10x greater efficiency of protein grown in a closed aqua farm is arguably another reason that this clean, green protein should become mainstreamed. As long as we can somehow encourage consumers to join in and to support the disruption of the traditional protein food chain. One tiny water lentil at a time.

Tangy, peppery, clean and green, it tastes nothing like chicken – but could it be the right protein for you? We’d love to know your thoughts!

References:

1. https://www.huffpost.com/entry/starbucks-drink-orders_n_3671496
2. https://medium.com/@soroshtavakoli/commercialising-the-worlds-most-sustainable-protein-plant-duckweed-b1f4d94e2655
3. https://www.npr.org/sections/thesalt/2017/02/13/515057834/90-percent-of-fish-we-use-for-fishmeal-could-be-used-to-feed-humans-instead
4. http://parabel.com/services/animal-feed/pigs-and-poultry/
5. http://parabel.com/services/animal-feed/ruminants-and-horses/
6. https://www.plantiblefoods.com/
7. https://www.prnewswire.com/news-releases/plantible-foods-completes-extractions-technology-raise-300733011.html
8. https://www.plantiblefoods.com/
9. https://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/GRAS/NoticeInventory/ucm608746.pdf