Overview
This study extracted oils from melon seed, groundnut and shea kernels by traditional manual methods and measured minerals, lead, copper, iron, zinc and anti-nutrients by AAS. Lead was reported at 0.0002 to 0.0004 mg/kg in all three oils. Cadmium, arsenic and mercury were not measured.
Key numbers
- Lead: melon oil “0.0004±0.00”, groundnut oil “0.0002±0.00”, shea butter oil “0.0003±0.00” (Table 2, p. 148; unit mg/kg from the text).
- Iron “0.0005± 0.03” to “0.0006±0.04” and zinc “0.0012±0.10” to “0.0015±0.13” (Table 2).
Methods (brief)
Seeds were sorted, washed, dried, toasted, milled and the oil extracted by boiling and scooping. Oils were digested and read by flame AAS (Buck 210 VGP) following AOAC methods. Results are means of triplicate analyses. No detection limits, reference materials or recoveries are reported.
Evidence Fitness
One laboratory-made batch per oil with weak QA. The lead values are far below what flame AAS can normally detect, and the iron and zinc standard deviations exceed their means by about a hundredfold, so the numbers are uncertain and carry flags. The Table 2 header prints no unit. These seed oils are a vegetable oil proxy for italian-dressing and rice-bran-oil (neither was measured), so those pages are not linked.