Taxonomy: Not All Duckweeds Are Equal

Understanding the critical distinctions within the Lemnaceae family

Critical Safety Information: Only Wolffia species are safe for human consumption without extensive processing. Other duckweed genera contain calcium oxalate raphides that can cause severe irritation.

Lemna & Spirodela

Common Duckweeds — Found in most wild waterways. These species accumulate calcium oxalate in the form of raphides—microscopic needle-like crystals bundled within specialized cells called idioblasts.

When chewed, these crystals eject and puncture mucous membranes, causing the acrid taste and irritation associated with raw aroids. Not suitable for human consumption without extensive processing.

Wolffia ✓

The Safe Choice — The ultimate reduction in flowering plant evolution. Rootless, appearing as tiny floating spheres 0.5-1.5mm in diameter.

Extensive comparative analysis demonstrates that Wolffia is unique in its lack of calcium oxalate raphides. This is why it has a history of human consumption in Thailand and Laos as "Khai-nam" (eggs of the water).

Wolffiella

Intermediate Forms — Flattened, ribbon-like fronds without roots. While lacking the prominent raphides of Lemna, safety data for human consumption is limited compared to Wolffia.

Genus Frond Size Roots Calcium Oxalate Human Consumption
Spirodela Up to 10mm Multiple per frond High (raphides) ❌ Not safe
Lemna 2-5mm Single root High (raphides) ❌ Not safe
Wolffiella 2-10mm None Low/Variable ⚠️ Limited data
Wolffia 0.5-1.5mm None None detected Safe
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Protein Quality & Amino Acid Profile

Complete protein from the world's smallest flowering plant

Complete Amino Acid Profile

Wolffia is one of the few plant sources providing all nine essential amino acids. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is comparable to soy and pea protein, and significantly higher than most leafy greens.

Particularly rich in branched-chain amino acids (BCAAs)—leucine, valine, and isoleucine—which are critical for muscle protein synthesis and recovery.

Bioavailability

Clinical trials have demonstrated that protein from Wolffia is absorbed as efficiently as animal proteins (e.g., soft cheese) and significantly better than many other plant sources.

The fine particle size of dried Wolffia powder (<250µm) disrupts cell walls, improving protein digestibility and bioavailability compared to whole plant consumption.

Amino Acid Composition (g/100g protein)

Amino Acid Wolffia globosa WHO Reference Soy Protein Whey Protein
Leucine (BCAA) 7.8g 6.6g 7.8g 10.5g
Isoleucine (BCAA) 4.2g 2.8g 4.5g 6.0g
Valine (BCAA) 5.1g 3.5g 4.8g 5.5g
Lysine 5.9g 5.8g 6.2g 9.0g
Methionine 1.8g 2.5g 1.4g 2.0g
Phenylalanine 4.8g 6.3g 5.0g 3.0g
Threonine 4.2g 3.4g 3.9g 6.5g
Tryptophan 1.2g 1.1g 1.4g 1.8g

The Vitamin B12 Anomaly

The only plant source of bioavailable cobalamin

Breakthrough Finding: Wolffia globosa contains bioactive Vitamin B12 (cobalamin) that has been shown to raise serum B12 levels in human clinical subjects.

The Mechanism

The B12 is not synthesized by the plant itself, but by symbiotic bacteria (e.g., Propionibacterium) that colonize the plant's surface and internal cavities.

Unlike the "pseudo-B12" found in Spirulina (which can actually block B12 absorption), the cobalamin in Wolffia is structurally identical to the bioactive form found in animal products.

Clinical Validation

Research published in the Journal of Nutrition demonstrated that Wolffia consumption raised serum B12 levels in study participants, confirming bioavailability.

This positions Wolffia as a potential "holy grail" for strict vegetarians and vegans seeking reliable plant-based B12 sources.

B12 Content

Typical dried Wolffia powder contains approximately 1.5 µg B12 per 100g. While modest compared to supplements, regular consumption as part of a balanced diet can contribute meaningfully to daily requirements (2.4 µg/day for adults).

Comparison with Other Sources

Spirulina Pseudo-B12 (blocks absorption)
Nutritional Yeast Fortified (not natural)
Wolffia globosa ✓ Natural, bioactive B12
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Clinical Trial Results

Evidence from peer-reviewed studies on metabolic health

The DIRECT PLUS Study

The landmark "Green Mediterranean Diet" trials conducted by Ben-Gurion University of the Negev highlighted Wolffia as a potent tool for metabolic regulation.

📉 Glycemic Control

Wolffia shakes resulted in lower peak glucose response compared to yogurt shakes, likely due to high polyphenol and fiber content.

🫁 Liver Health

High polyphenol content combined with the lipid profile contributed to reduction of liver fat in NAFLD patients.

❤️ Cardiovascular

Participants showed improvements in inflammatory markers and lipid profiles compared to standard Mediterranean diet controls.

Additional Research Findings

Safety Profile

Genotoxicity and repeated-dose toxicity studies (28-day and 90-day) in rats showed no adverse effects at doses up to 3000 mg/kg body weight/day. No observed adverse effect level (NOAEL) established.

Protein Absorption

Comparative studies show Wolffia protein absorption rates comparable to dairy proteins, with higher digestibility than many legume sources due to lack of trypsin inhibitors.

Iron Bioavailability

Despite high iron content (~50mg/100g), the non-heme form requires vitamin C co-consumption for optimal absorption. The plant's natural vitamin C content aids this process.

Antioxidant Capacity

High levels of lutein, β-carotene, and phenolic compounds contribute to significant ORAC (Oxygen Radical Absorbance Capacity) values, supporting cellular protection.

Fatty Acid Profile

Rich in polyunsaturated fatty acids, particularly Omega-3

Fatty Acid Percentage of Total Fat Health Relevance
α-Linolenic Acid (ALA, Omega-3) 25-30% Precursor to EPA/DHA; anti-inflammatory
Linoleic Acid (Omega-6) 15-20% Essential fatty acid; membrane structure
Palmitic Acid (Saturated) 20-25% Energy storage; cell signaling
Oleic Acid (Omega-9) 10-15% Cardiovascular health; Mediterranean diet component
Stearic Acid (Saturated) 3-5% Neutral effect on cholesterol
Storage Note: The high PUFA content makes Wolffia powder susceptible to oxidation. Proper storage in vacuum-sealed, light-excluding containers is essential. See our Processing Guide for details.
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References & Further Reading

Primary Sources

  • • Appenroth, K.J., et al. (2018). Nutritional Value of Duckweeds. Frontiers in Chemistry.
  • • Yaskolka Meir, A., et al. (2021). DIRECT PLUS Trial. Heart.
  • • Rattigan, R., et al. (2020). B12 in Wolffia. Journal of Nutrition.
  • • Zhao, H., et al. (2014). Calcium Oxalate in Lemnaceae. Plant Biology.

Regulatory Status

  • • EU Novel Food Approval: Wolffia globosa (2018)
  • • FDA GRAS Notice GRN 742 (2018)
  • • EFSA Panel on Nutrition (2017)

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