Radical Sustainability – Pond Scum as the New Alt-Protein (An Update)

Duck Weed

Even outside of St. Patrick’s Day with its shamrock milkshakes, leprechaun cupcakes, and the always popular viridian beer (with drinkers green to the gills the following day), we hear a lot about green these days. Look in any paper or online news source and you’ll find myriad articles on becoming more green, green-washing, and most recently the Green New Deal. But that’s not what we want to talk about today. We’re excited to take chartreuse, olivine, emerald, or any other shade of the color to a whole new level, and it’s one we’ve looked at in a previous article. To get up to speed or simply refresh yourself on the basics, head over to ‘Duckweed – Why Tiny Pond Scum Might Be A Big Innovation in Plant-Based Nutrition’ for a quick run down – go ahead, we’ll wait… You’re back? Excellent! So let’s turn the page on the ‘common or garden’ duckweed and start a new chapter in this innovative new food source: Wolffia globosa.

Wolffia what? Wolffia globosa, aka ‘Asian Watermeal’ (which is less of a linguistic, if not culinary, mouthful), is a species of tiny flowering plant found natively in Asia and the Americas.

Devoid of stems, leaves, or roots, the plant body is less than one millimeter in width and thrives by forming mats on or near the surface of areas of freshwater such as lakes, marshes and ponds.

So is making dinner as simple as donning waders and skimming the weed from your garden pond with a fishing net?

We suppose that’s possible but an easier – and altogether safer – alternative is being developed by Hinoman, an Israeli startup focused on supplying a ‘safe, nutritious leaf protein source.’(1) Founded by Udi Elituv, the enterprise is populated by entrepreneurs, academics, food engineers, and agronomists and, after an 8-year cycle of research and development, it owns the sole patent on a product called Mankai™ Plant. Mankai is perhaps the epitome of ‘green cuisine,’ with a nutrition profile that is more protein-packed than edamame, contains more fiber than spirulina, and is higher in minerals (including zinc and iron) and Vitamins A, E, and B2 than kale – all of which are regarded as ‘superfoods.’ In addition, it is rich in polyphenols (especially phenolic acids and flavonoids) and is one of the few plants to produce vitamin B12. According to Hinoman, Mankai™ is a complete protein with a profile close to the nutritional ‘Gold Standard,’ the egg. Surprisingly for a weed, it has a versatile neutral taste that makes it ideal in raw form, as a general food ingredient, or as a supplement. Moreover, it is devoid of common allergens such as nuts, soy, and gluten, and is low in sodium, fat, sugar, and carbohydrates. The cherry on top of the cake? It is also GMO-free.

On first inspection, it sounds like a perfect food but little is known about how the duckweed species mankai is metabolized.

According to an article in Food Navigator, a news source for the food industry, researchers at Ben Gurion University of the Negev created a sub-study as part of their broader ‘Dietary Intervention Randomized Controlled Trial – Polyphenols Unprocessed (DIRECT PLUS),’ which sought to analyze the impact of a green Mediterranean diet. In collaboration with the Harvard School of Public Health (USA) and the University of Leipzig (Germany), the researchers examined participants diagnosed with Abdominal Obesity Metabolic Syndrome, twenty of whom were prescribed a shake containing either duckweed or dairy, in the form of yoghurt.(2) Among those receiving the ‘green shake,’ blood glucose levels were lowered when measured both at morning fasting times and at later peak levels. Additionally, faster glucose evacuation was observed and participants reported satiety at higher levels and for a longer duration than those whose shakes contained dairy. So, to summarize, as researchers noted: ‘It is the aggregation of all of these properties which seem to make the easily integratable, tasteless, and odorless plant a good candidate to become a superfood.’(3)

So if it’s such a health-promoting food, what’s the catch?

Maybe sustainability is an issue? Duckweed in general, and mankai in particular, occurs naturally on the surface of water. Therefore, in growing it for consumption, Hinoman developed a hydroponic system which is said to cultivate a clean product uncontaminated by pesticides, fungicides, or growth stimulators. In terms of governmental regulation, this is good news as it offsets concerns around food safety regarding contamination.

Plus it is scalable.

With an increasing need to mainstream hitherto alternative sources of protein, wolffia is a plant that proliferates rapidly, can be harvested year-round, and offers a high yield. Hydroponic cultivation by-passes the problems associated with soil erosion, contamination, and land area limitations and – significantly – the process requires less energy and less water lost from drainage, run-off, or evaporation. All in all, the picture is one of a ‘near-zero ecological footprint.’(4) And this is a good sign for many reasons, including market stability. With a continuous source of product, third party manufacturers of food items such as pastas, protein bars, nutritional shakes or smoothies, breads or other baked goods, and functional foods can seemingly have confidence in both the integrity of their supply chain and raw ingredient pricing.

So it’s a win for Hinoman and for downstream manufacturers and consumers? Yes and no.  

Certainly a new protein source is exciting for food producers, retailers, and consumers, but Hinoman doesn’t have the market sewn up. Although exclusive national sales rights to Mankai™ have been hotly contested with, for example, Ajinomoto Co., Inc. celebrating winning the rights to sell into the Japanese market, Hinoman is not the only player on the field. Although Mankai™ is a patented and trademarked product, other manufacturers of duckweed-derived foods are also looking for their share of the alt-protein pie. Enter Parable and Plantible…

In August of this year, Vero Beach, FL-based company Parabel announced the launch of a neutrally colored protein created from water lentils. In a press release, the company outlined the benefits of its LENTEIN® product line without mentioning the other name for water lentils – duckweed – perhaps in an attempt not to lose a segment of its audience.(5) LENTEIN® contains a 65-70% hydrolyzed protein with a complete amino acid profile that is allergen-free and non-GMO. Highly digestible, it is destined for use in any plant-based food, from July 4th cookout burgers to high-function sports drinks. And, unlike Mankai™, LENTEIN® is available in a range of formats including a flour and a milk, in addition to the original protein hydrolysate.

According to data contained in a U.S. Food and Drug Administration (FDA) letter to Parabel, the process for manufacturing the company’s main products – duckweed powder (DWP) and degreened duckweed powder (DDWP) – involves harvesting the plants from ‘open field hydroponic growth areas. The duckweed is pre­screened to remove any foreign materials and fed to a thermal washing system to eliminate microbes and pathogens, deactivate enzymes, and remove undesirable components. The material is then dewatered, dried, and milled to obtain DWP [which is described as] a free-flowing, green powder. To obtain DDWP, Parabel extracts fats and plant pigments from dewatered duckweed using 95% food-grade ethanol. The material is then dried and milled.’(6) When prepared in this way, the FDA concludes that both products are Generally Recognized As Safe (GRAS), although the letter does note that the DWP, when used as a color additive in other food products, is not GRAS and may require a color additive petition when used in this way by downstream manufacturers.

Plantible is a company we discussed in our previous article on duckweed and we’re glad to see that it now offers somewhat more information on its process than at the last time of writing. Using the term ‘lemna’ for its water lentils, Plantible uses an indoor aqua farm for increased environmental control and, in contrast with Parabel’s open ponds which are reminiscent of the cranberry bogs of New England, Plantible’s indoor technology optimizes the nutritional profile of the greens. Plus the system is pesticide- and hexane-free, and biomass processing relies on cold-press extraction – much, one imagines, like that of olive oil production – with the resulting white colored protein being produced on a daily basis. According to Plantible’s own data, the manufacturing process is set up to be ‘transparent and traceable’ but we would like to see a lot more information offered in terms of supply chain analysis and the ‘proprietary extraction technology [and] developed technologies [that] optimize growth rates.’(7) We have to assume that such information will become available as the product and the company gain market traction.

As always with new and innovative food products, however, we do have to focus the spotlight on safety.

In its whole plant form, duckweed – and therefore mankai – has been consumed for hundreds of years in areas of Southeast Asia such as Burma, northern Thailand, and Laos, giving it a solid pedigree. Prized for its high protein content, it is no surprise that the plant’s long history of consumption along with its purported health benefits have earned it a GRAS status by the FDA. Moreover, Hinoman, the Israeli start-up with whom we began this journey and the company receiving arguably the most attention in this field, lists confirmation of both Hazard Analysis and Critical Control Points (HACCP) protocols and ISO9001 status on its website. To date, Parabel, on the other hand, does not. But the company, and any other players in this nascent field really should have transparency around their safety protocols and designations. If the early promise of the nutrition powerhouse that is duckweed – in any of its variety of species – is to attain early adoption and broad acceptance, it simply must gain governmental approval and mainstream confidence. Increasingly we are seeing an uptick in public interest in kinder and more healthful alternatives to traditional foods – as the unanticipated success of Burger King’s rollout of the Impossible Burger strongly attests – and whole-food, plant-based options are firmly on the menu.(9) Lemna, duckweed, mankai, water lentil, asian watermeal…whatever you call it, this diminutive plant looks to have a massive potential, providing that it is carefully cultivated and diligently harvested to create a clean, contamination-free product.

With that said, we do acknowledge that the aquatic greens – whatever their specific or branded name – may not appeal to all consumers as an alt-protein, so let’s remind ourselves of the other options we’ve discussed. On perhaps the most innocuous – or acceptable – end of the spectrum are the plant-based meat alternatives such as the Beyond Burger (see ‘Clean Meat: Can a Flesh-Based Product Ever Be Considered Contamination-Free?‘) which are generally an easy taste to acquire. Also on the spectrum are the lab-grown proteins that we discussed in ‘How Bioreactors and Cleanroom Technology Might Be the Answer to Declining Seafood Stocks’ – one even being grown in space (see ‘How Space-Grown Beef Could Feed the Planet‘) that may take a little more getting used to before they achieve widespread acceptance by diners. And then, of course, the truly avant-garde – the insect-derived protein sources (see ‘Chirps in the Cleanroom: Are Cultured Crickets the Future of Cellular Agriculture?‘), whether naturally farmed or lab-cultured, which may become the preserve only of the most adventurous of eaters. With that said, however, an article published last week in Grub Street, an online hub for all matters relating to the New York metropolitan scene, asked the city’s ‘cutting edge chefs’ to hypothesize the shape of meals of the future. Given climactic changes, increasing pressure on natural resources, and shifts away from traditional dishes, the chefs’ concepts were radical indeed. Our favorite? Gotham Bar & Grill’s new chef Victoria Blamey suggested a repast ‘made entirely of kitchen scraps […] all animal parts, leftover veg, and produce that is no longer beautiful, but nutritious.’(8) The result? Intestine Chicharron, Tomato Redux, and Fermented Cabbage.

Erm…is anyone still hungry…?

Have you come across foods using duckweed as an ingredient? How did it taste? Did you enjoy the meal? Would you avoid this micro-green in favor of more traditional sources of protein? Tell us your thoughts – we’d love to hear from you!


  1. https://www.hinoman.com/who-we-are/
  2. https://www.foodnavigator-usa.com/Article/2019/10/30/Mankai-duckweed-a-fully-fledged-superfood-New-research-demonstrates-the-green-protein-s-health-benefits
  3. ibid
  4. https://www.hinoman.com/what-we-do/#plant
  5. https://www.prnewswire.com/news-releases/parabel-announces-breakthrough-solution-to-plant-based-foods-in-pure-protein-hydrolysate-300900531.html
  6. https://www.fda.gov/media/116248/download
  7. https://www.plantiblefoods.com/#how
  8. http://www.grubstreet.com/2019/11/10-trailblazing-chefs-cook-the-food-of-the-future.html
  9. See CNN (https://www.cnn.com/2019/10/28/investing/restaurant-brands-earnings-burger-king-popeyes/index.html) and CNBC (https://www.cnbc.com/2019/10/16/the-impossible-whopper-is-driving-steady-traffic-to-burger-king-data-shows.html), or Mercy for Animals (https://mercyforanimals.org/impossible-whopper-one-of-the-most-successful)

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