Overview
This study determined concentrations of 22 elements including toxic metals (Pb, Cd, Al, Cr, Ni, U) and essential elements in 56 green and roasted coffee bean samples representing five origins (Brazil, Colombia, Ethiopia, Guatemala, Yemen) collected from the Jordanian market. ICP-MS analysis was performed following microwave-assisted acid digestion. Roasting was found to affect elemental concentrations differentially: some toxic metals increased on a dry-weight basis after roasting due to mass loss, while absolute content per bean was unchanged. Concentrations of all toxic metals were below EU maximum limits for contaminants in food.
Key numbers
56 samples; 5 geographic origins; 22 elements by ICP-MS. Pb range: green 0.012–0.089 mg/kg, roasted 0.013–0.099 mg/kg (values from Table 2, source). Cd range: green 0.003–0.021 mg/kg, roasted 0.003–0.024 mg/kg. U range: green 0.001–0.009 mg/kg, roasted 0.001–0.010 mg/kg. Ni range: green 0.42–1.87 mg/kg. Cr range: green 0.08–0.42 mg/kg. Al range: green 0.21–3.10 mg/kg. All values dry weight basis. LODs/LOQs reported per element in source methods. All results below EU Regulation 2023/915 limits.
Methods (brief)
ICP-MS (Agilent 7700) following microwave-assisted acid digestion (HNO3/H2O2). Certified reference material NIST 1568b used for QC. LODs and LOQs specified per element. Wet-to-dry weight conversion applied; dry weight basis reported throughout.
Implications
Certification: Pb and Cd in coffee are relevant to HMT&C product assessments for coffee-containing products. Roasting effect data useful for processing-step correction. Courses: Demonstrates roasting impact on metal concentrations; useful for supply-chain and processing modules. App: Pb, Cd, Ni, Al, Cr, and U values in coffee beans are directly useful for ingredient contamination profiling.
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Update history
The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and 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.
| Commit | Date | Change | Description |
|---|---|---|---|
| e317189 | 2026-08-11 | correction | 6 sections added; narrative text revised |