Overview
Janvier et al. measured minerals, vitamins, protein, and sugars in root bark of Mondia whytei, a Rwandan wild edible plant consumed fresh or powdered as a food supplement. The heavy-metal-relevant findings are dry-weight lead (Pb) and cadmium (Cd) concentrations in root bark across Rwandan localities and in old versus young Byangabo plants.
Key numbers
Table 3 reports mineral concentrations in mg/g dry matter by locality. Lead ranged from 0.03 to 0.06 mg/g: Mukinga 0.05 +/- 0.00 mg/g, Busogo 0.03 +/- 0.00 mg/g, Kinkware 0.06 +/- 0.00 mg/g, Byangabo 0.03 +/- 0.00 mg/g, and Kinigi 0.06 +/- 0.01 mg/g. Cadmium ranged from 0.05 to 0.09 mg/g: Mukinga 0.09 +/- 0.02 mg/g, Busogo 0.05 +/- 0.01 mg/g, Kinkware 0.05 +/- 0.02 mg/g, Byangabo 0.09 +/- 0.00 mg/g, and Kinigi 0.08 +/- 0.01 mg/g.
Table 3 also reports essential-element values in mg/g dry matter. Across localities, Fe ranged from 0.21 to 0.44 mg/g, Zn from 0.04 to 0.07 mg/g, Cu from 0.003 to 0.01 mg/g, and Mn from 0.04 to 0.05 mg/g. The same table reports macro-minerals, including K from 11.34 to 32.05 mg/g, Na from 5.61 to 24.13 mg/g, Mg from 1.40 to 2.93 mg/g, and Ca from 3.09 to 8.26 mg/g.
Table 4 compares Byangabo root bark by plant age, in mg/g dry matter. The old three-year sample contained 0.03 +/- 0.00 mg/g Pb and 0.09 +/- 0.00 mg/g Cd. The young 1.5-year sample contained 0.06 +/- 0.00 mg/g Pb and 0.05 +/- 0.00 mg/g Cd.
Methods (brief)
The authors collected Mondia whytei root bark from five Rwandan localities in Musanze District and compared full-grown plants, described as above three years old, with a younger 1.5-year Byangabo sample. The root bark was washed, dried at 35 degrees C, milled, sieved, and refrigerated before analysis. Samples were prepared in triplicate.
Ca, Mg, Zn, Cd, Pb, Cu, Mn, and Fe were measured by atomic absorption spectrophotometry. Cd, Pb, Fe, and Cu used nitric acid/perchloric acid digestion before AAS. Na and K were measured by flame emission spectrophotometry. The paper reports total elements, not arsenic or mercury speciation.
Implications
Microbiome: Not applicable.
Related evidence
- Ingredient class — botanicals/herbs/traditional formulas
- Herbal botanicals
- Lead
- Cadmium
- Iron
- Zinc
- Copper
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