EFSA NDA Panel 2022 — Safety of Lemna minor and Lemna gibba as novel food
This EFSA scientific opinion evaluates the safety of heat-treated water lentils (Lemna minor and Lemna gibba whole plant material) as a novel food under Regulation (EU) 2015/2283. As part of the compositional assessment, the applicant provided heavy metals data for ten production batches by ICP-MS. The Panel found As, Cd, and Hg below their respective LOQs across all batches, and Pb detected in only a few batches at trace levels. The opinion concluded the novel food could not yet be established as safe primarily due to manganese intake concerns rather than heavy metal levels.
Key numbers
Heavy metals measured in 10 batches (five Lemna minor, five Lemna gibba), expressed on fresh weight (FW) basis by ICP-MS (NEN EN 13805 and 17294-2):
- Arsenic: <0.02 mg/kg FW in all 10 batches (all below LOQ of 0.02 mg/kg = 20 µg/kg = 20 ppb FW)
- Cadmium: <0.01 mg/kg FW in all 10 batches (all below LOQ of 0.01 mg/kg = 10 µg/kg = 10 ppb FW)
- Mercury: <0.01 mg/kg FW in all 10 batches (all below LOQ of 0.01 mg/kg = 10 µg/kg = 10 ppb FW)
- Lead: detected in batches #1 (0.030 mg/kg), #2 (0.020 mg/kg), and #6 (0.012 mg/kg); below LOQ (<0.01 mg/kg) in the remaining 7 batches. Range where detected: 0.010–0.030 mg/kg FW (10–30 µg/kg FW = 10–30 ppb FW)
Methods (brief)
Multi-element ICP-MS analysis of 10 commercial production batches following NEN EN 13805 (microwave-assisted pressure digestion) and NEN EN 17294-2 (ICP-MS quantification). Results expressed on fresh weight basis. Certificates of accreditation for laboratories provided by applicant.
Implications
Certification: water lentils / duckweed as an emerging protein ingredient show low heavy metal contamination under the reported cultivation conditions, with As, Cd, and Hg consistently below detection and Pb at trace levels. The EFSA opinion notes that trace element concentrations are highly dependent on cultivation conditions and fertilizer composition, making lot-level monitoring essential.
Courses: illustrates how novel food safety assessment includes mandatory heavy metals characterization as part of the compositional dossier.
App: water lentils and duckweed ingredients currently show below-LOQ As, Cd, Hg; Pb detected intermittently at 10–30 ppb FW.