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Duckweed (Wolffia globosa, Wolffia arrhiza, and Lemna minor) as novel therapeutic food for acute malnutrition and famine alleviation in low- and middle-income countries and humanitarian crisis settings

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Overview

This 11-page review from Johns Hopkins assesses the potential of Wolffia globosa, Wolffia arrhiza, and Lemna minor as therapeutic foods for acute malnutrition in low- and middle-income countries and humanitarian crisis settings. Table 4 compiles mineral composition data from multiple primary studies under controlled cultivation conditions (freeze-dried weight basis). The review notes that arsenic accumulation from cultivation medium is a recognized risk and that controlled conditions maintain levels below food safety thresholds. PDCAAS and DIAAS scores for protein quality are reported.

Key numbers

Mineral composition ranges from controlled cultivation, Table 4 (freeze-dried weight basis, compiled from primary studies):

Wolffia globosa:

  • Iron: 100-290 mg/kg FDW
  • Manganese: 203-302 mg/kg FDW
  • Copper: 2.32-4.43 mg/kg FDW
  • Zinc: 38-84.20 mg/kg FDW

Wolffia arrhiza:

  • Iron: 160-290 mg/kg FDW
  • Manganese: 78.40-264 mg/kg FDW

Arsenic accumulation from cultivation medium cited as a risk factor; range 0.3-2.52 mg/kg from various primary studies (basis mixed).

Protein quality:

  • W. globosa: PDCAAS 89%
  • W. arrhiza: DIAAS 0.75 (above wheat 0.40, peas 0.64)

Methods (brief)

Systematic literature review. Table 4 values are compiled ranges from multiple primary studies under controlled cultivation conditions; the review authors do not conduct original measurements. Freeze-dried weight (FDW) basis is stated for Table 4 mineral data.

Evidence Fitness

Mineral composition (beneficial and potentially toxic) under controlled cultivation conditions. The manganese values (203-302 mg/kg FDW for W. globosa) are relevant to the cultivation-condition accumulation discussion. At 3% dry matter, 302 mg/kg FDW converts to approximately 9 mg/kg FW, which exceeds EFSA’s 6 mg/kg FW manganese limit for fresh Wolffia. This source provides context for the manganese proximity concern but not original heavy metals food-safety measurements. It does not report lead (Pb), cadmium (Cd), or mercury (Hg) concentrations. Arsenic range is from mixed sources; use as contextual range, not a food-grade measurement row.

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