Romero-Estevez et al. 2019 — Cd, Ni, and Pb in Ecuadorian Cocoa Beans (Nine Provinces)
This peer-reviewed study, published in Food Control (accepted manuscript form), measured cadmium, nickel, and lead concentrations in cocoa beans from nine Ecuadorian provinces using flame atomic absorption spectrophotometry (FAAS) and graphite furnace atomic absorption spectrophotometry (GFAAS), and applied multivariate regression and Pearson correlation analysis to assess whether the three metals co-vary. The key finding is that Ni was the most abundant metal in all samples, Cd was present at concentrations exceeding the EU 0.8 mg/kg threshold in 33.3% of samples, and the three metals did not demonstrate significant linear correlation with each other, meaning remediation of one metal does not predict co-reduction of the others.
Key numbers
Cd in Ecuadorian cocoa beans: range 0.267–1.715 mg/kg; mean 0.753 mg/kg. 33.3% of samples exceeded EU threshold of 0.80 mg/kg.
Pb in Ecuadorian cocoa beans: range 0.502–1.966 mg/kg; mean 1.432 mg/kg. Note: These Pb concentrations are high relative to other studies; no current EU/Codex regulatory limit exists for Pb in raw cacao beans.
Ni in Ecuadorian cocoa beans: range 1.462–8.528 mg/kg; mean 3.930 mg/kg. Ni was the most abundant of the three metals. No regulatory limit for Ni in cacao beans is established by EU or Codex.
Correlation analysis: Regression analysis R² < 0.2420746; Pearson correlation coefficient < 0.369; variance inflation factors < 1.319. These results demonstrate no linear correlation or multivariate regression relationship among Cd, Ni, and Pb content.
Methods (brief)
Analytical method: FAAS and GFAAS. Provenance: nine Ecuadorian provinces (unspecified which in abstract; full province breakdown in paper body). Digestion method and certified reference material details in manuscript. Institution: CESAQ-PUCE (Centro de Estudios Aplicados en Química, Pontificia Universidad Católica del Ecuador).
Limitations
This is an accepted manuscript; final typeset version may differ. Specific province-level data were not extracted from the first 5 pages — the province breakdown is in the results section beyond the pages read. The Pb values (mean 1.432 mg/kg) are notably high for cacao beans; no established regulatory limit makes interpretation difficult. The FAAS method used for Cd has lower sensitivity than ICP-MS and may affect detection at lower concentrations. Sample size not stated in abstract.
Implications
- Certification: Confirms that Cd in Ecuadorian cocoa frequently exceeds EU 0.80 mg/kg bean-equivalent threshold. The absence of Ni-Pb-Cd correlation means each metal needs independent supply-chain monitoring rather than proxy inference from Cd alone. HMT&C Ni and Pb testing for cocoa is not redundant with Cd testing.
- Courses: The lack of inter-metal correlation is a practically important finding for supply-chain risk management: a clean Cd result does not predict clean Ni or Pb.
- App: Provides Ecuador-specific Cd range (0.267–1.715 mg/kg) for geographic_breakdown entry on cocoa.
- Microbiome: Not applicable.