Janvier et al. 2019 — Metals in Mondia whytei root bark used as a food supplement

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 Pb and 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.

The authors state that Pb was the lowest mineral in the abstract, with a study range of 0.03 to 0.06 mg/g dry matter. They also state that the measured Cd and Pb concentrations were within plant-tissue ranges and below cited tolerable-intake context, but those interpretive statements are source-scope context rather than HMTc threshold conclusions.

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

Certification: This source contributes occurrence evidence for a botanical root-bark ingredient used as a food supplement, not for vitamin-mineral supplement premixes generally. Values are high-concentration dry-weight plant-powder measurements and should not be pooled with finished capsule, tablet, tincture, or beverage values without explicit basis and product-form adjudication.

Courses: The paper is useful for explaining how wild-harvest locality and plant age can shift mineral and toxic-metal concentrations in botanical supplement ingredients.

App: The source can support a botanical-supplement evidence card for Pb and Cd in Mondia whytei/root-bark products, with a dry-weight basis flag.

Microbiome: Not applicable.

Wiki pages this source may touch

• supplements-botanicals-herbs
• herbal-botanicals
• lead
• cadmium
• iron
• zinc
• copper

Verification notes

The DOI, authors, journal, license, and final citation are visible in the PDF. The auto-fetched filename places this in a vitamin-mineral supplement lead queue, but the actual matrix is Mondia whytei root bark used as a wild edible plant and food supplement. Table 3 appears to repeat Kinkware as the last column while the discussion identifies that high-K/Pb column as Kinigi; this page follows the table values and notes the locality label issue for future synthesis review.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.