Overview
Sirison and colleagues grew Wolffia globosa (watermeal) in four nutrient media in outdoor tanks in Bangkok and compared yield, composition and safety, then used the dried biomass in fresh pasta and fried sweet potato balls. Table 4 reports lead, arsenic, cadmium and mercury in the biomass from each medium against printed standards.
Key numbers
- Lead: 0.10 to 0.13 mg/kg across the four media (Table 4).
- Arsenic: 0.01 to 0.02 mg/kg; cadmium 0.01 to 0.02 mg/kg; mercury 0.01 mg/kg in every medium (Table 4).
- No significant difference in any metal between media (Table 4).
Methods (brief)
Biomass from four replicate tanks per medium was analyzed by AOAC methods using graphite furnace AAS and ICP-MS. No detection limits, reference materials or recoveries are reported, and the table does not state whether metal values are on a fresh or dry basis.
Evidence Fitness
Experimental cultivated biomass from one site, not a market survey. Values are close to the two-decimal reporting precision with SDs printed as 0.00, and the basis is unclear. It does measure water lentil (Wolffia) biomass directly. The fortified foods were not tested for metals.