This Sri Lankan study compares elemental concentrations and simulated digestive release in two leafy vegetables across five growing areas. Raw, coconut-milk-cooked and coconut-oil-stir-fried portions were tested separately; lower in-vitro release does not establish lower human absorption or safe consumption.
Key numbers
Total plant content, mg/kg, with source ± dispersion:
| Species | Area | Metal | Total |
|---|---|---|---|
| Alternanthera sessilis | Piliyandala | Ni | 3.02±1.02 |
| Alternanthera sessilis | Piliyandala | Cd | 0.20±0.01 |
| Alternanthera sessilis | Piliyandala | Cr | 0.82±0.20 |
| Alternanthera sessilis | Piliyandala | Pb | 0.24±0.04 |
| Alternanthera sessilis | Piliyandala | Cu | 7.85±2.21 |
| Alternanthera sessilis | Wellampitiya | Ni | 8.42±2.25 |
| Alternanthera sessilis | Wellampitiya | Cd | 0.36±0.06 |
| Alternanthera sessilis | Wellampitiya | Cr | 4.59±1.11 |
| Alternanthera sessilis | Wellampitiya | Pb | 3.14±0.98 |
| Alternanthera sessilis | Wellampitiya | Cu | 15.40±3.23 |
| Alternanthera sessilis | Kolonnawa | Ni | 11.35±2.76 |
| Alternanthera sessilis | Kolonnawa | Cd | 0.86±0.04 |
| Alternanthera sessilis | Kolonnawa | Cr | 6.74±2.22 |
| Alternanthera sessilis | Kolonnawa | Pb | 3.05±1.01 |
| Alternanthera sessilis | Kolonnawa | Cu | 10.30±2.99 |
| Alternanthera sessilis | Kottawa | Ni | 9.15±1.87 |
| Alternanthera sessilis | Kottawa | Cd | 0.22±0.05 |
| Alternanthera sessilis | Kottawa | Cr | 5.05±1.23 |
| Alternanthera sessilis | Kottawa | Pb | 3.89±1.00 |
| Alternanthera sessilis | Kottawa | Cu | 10.90±2.45 |
| Alternanthera sessilis | Bandaragama | Ni | 2.02±0.98 |
| Alternanthera sessilis | Bandaragama | Cd | 0.11±0.01 |
| Alternanthera sessilis | Bandaragama | Cr | 0.78±0.07 |
| Alternanthera sessilis | Bandaragama | Pb | 0.31±0.05 |
| Alternanthera sessilis | Bandaragama | Cu | 6.96±1.45 |
| Centella asiatica | Piliyandala | Ni | 2.11±1.01 |
| Centella asiatica | Piliyandala | Cd | 0.15±0.05 |
| Centella asiatica | Piliyandala | Cr | 0.72±0.12 |
| Centella asiatica | Piliyandala | Pb | 0.27±0.09 |
| Centella asiatica | Piliyandala | Cu | 10.60±2.12 |
| Centella asiatica | Wellampitiya | Ni | 14.06±3.12 |
| Centella asiatica | Wellampitiya | Cd | 0.32±0.08 |
| Centella asiatica | Wellampitiya | Cr | 5.82±2.03 |
| Centella asiatica | Wellampitiya | Pb | 5.90±2.01 |
| Centella asiatica | Wellampitiya | Cu | 16.26±5.21 |
| Centella asiatica | Kolonnawa | Ni | 16.55±5.25 |
| Centella asiatica | Kolonnawa | Cd | 0.45±0.11 |
| Centella asiatica | Kolonnawa | Cr | 11.33±2.31 |
| Centella asiatica | Kolonnawa | Pb | 10.23±1.98 |
| Centella asiatica | Kolonnawa | Cu | 21.22±6.86 |
| Centella asiatica | Kottawa | Ni | 11.23±2.45 |
| Centella asiatica | Kottawa | Cd | 0.30±0.08 |
| Centella asiatica | Kottawa | Cr | 4.36±2.00 |
| Centella asiatica | Kottawa | Pb | 3.21±1.98 |
| Centella asiatica | Kottawa | Cu | 16.22±5.43 |
| Centella asiatica | Bandaragama | Ni | 1.45±0.98 |
| Centella asiatica | Bandaragama | Cd | 0.15±0.07 |
| Centella asiatica | Bandaragama | Cr | 0.63±0.12 |
| Centella asiatica | Bandaragama | Pb | 0.30±0.12 |
| Centella asiatica | Bandaragama | Cu | 5.32±0.57 |
Every gastric/intestinal concentration, percentage, dispersion and ND cell from Tables 1–2 is retained in the structured batch table. Overall gastric/intestinal bioaccessibility reported on p 8: nickel (Ni) 9.98/3.51%, cadmium (Cd) 9.46/5.81%, chromium (Cr) 3.93/1.97%, lead (Pb) 9.70/3.15%, Cu 13.8/33.6%; pooled denominators are not explicit.
Methods (brief)
80 samples across Piliyandala, Wellampitiya, Kolonnawa, Kottawa, Bandaragama. Each edible sample split into 200 g portions: raw; 50 mL coconut milk cooking; 15 mL coconut oil stir-frying, 12 minutes at 95±2°C. PBET at 37°C uses gastricpH 2.5 for 1 h and intestinalpH 7 for 2 h. ICP-OES; total analysis by AOAC 999.11 dry ashing. SpinachCRM recovery 96–104%; LODµg/g: Ni 0.025, Cd 0.005, Cr 0.010, Pb 0.050, Cu 0.015. Reported concentration moisture basis is not explicit.
Implications
Supports region-specific leafy-vegetable occurrence and cooking/bioaccessibility comparisons. Processing effects are not uniform: for example Wellampitiya A. sessilis gastric Pb is 15.3% raw and 20.7% cooked. Coconut additions can change the matrix; an in-vitro endpoint is not in-vivo absorption.
Evidence Fitness: EF-2 for source concentrations and region/treatment comparisons; EF-3 for modeled digestive exposure. Keep total plant results separate from digest fractions and preserve nondetection.
Related evidence
- Leafy / Green Vegetables, Other
- Leafy Vegetables
- Processing mitigation
- Nickel
- Cadmium
- Chromium
- Lead
- Copper
Update history
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