What was reviewed?
This perspective article reviewed the scientific and regulatory landscape surrounding cadmium (Cd) and lead (Pb) contamination in cocoa and chocolate products. The review systematically examined the origin and occurrence of these heavy metals in cocoa and chocolate, the influence of geographic origin and cocoa content on contamination levels, and the environmental and processing factors that contribute to their presence. It also explored the international regulatory response to these contaminants, including the establishment of maximum limits (MLs) by authorities like the European Commission and the Codex Alimentarius Commission, as well as mitigation strategies and ongoing research aimed at reducing Cd and Pb in cocoa and chocolate. The review emphasized the complexity of heavy metal uptake by cacao trees, outlined regional differences, and highlighted the challenges faced by producers, particularly in Latin America, in meeting international standards.
Who was reviewed?
The review synthesized findings from a broad range of studies on cocoa beans and chocolate products, with a primary focus on geographic regions significant to global production: West Africa (notably Côte d’Ivoire and Ghana), Latin America (especially Brazil, Ecuador, and Peru), and Southeast Asia (including Indonesia and Papua New Guinea). The reviewed studies included analyses of both milk and dark chocolate, cocoa nibs, and cocoa powder, examining products from these regions as well as processed products on international markets. The article referenced scientific investigations, regulatory assessments, and mitigation research, drawing on field studies of soil and agronomic factors, as well as government and industry reports. The populations of interest were not individual people, but rather cocoa-producing regions, chocolate manufacturers, and the international regulatory community.
Most important findings
| Critical Points | Details |
|---|---|
| Geographic variation in Cd and Pb levels | Cocoa and chocolate from Latin America (except Brazil) have higher Cd, while Pb is not strongly linked to geographic origin. |
| Partitioning in chocolate types and product composition | Cd predominantly accumulates in non-fat cocoa solids, leading to higher levels in dark chocolate; Pb distributes more evenly. |
| Health and regulatory benchmarks | JECFA and FDA found that cocoa/chocolate are not major dietary sources of Cd and Pb, but EU set strict MLs for Cd in 2019. |
| Key drivers of contamination | Soil Cd is mainly responsible for cocoa Cd content. Soil pH, Zn content, and amendments (lime, biochar) can reduce uptake. |
| Pb sources and mitigation | Pb contamination often occurs post-harvest or during processing; best mitigated by good practices and avoiding Pb equipment. |
| Mitigation research status | Soil amendments, reduced fertilizer use, agroforestry, and genetic selection are promising for Cd; blending beans is common. |
| Regulatory and trade implications | Stringent EU MLs for Cd threaten Latin American exports; Codex working on global standards and mitigation codes of practice. |
| Industry and international response | Ongoing research, regulatory updates, and industry settlements are driving mitigation strategies and regulatory evolution. |
Key implications
For heavy metal certification programs, the review highlights that controlling cadmium in cocoa requires region-specific soil management and rigorous sourcing, especially for Latin American beans. Lead contamination is best managed through strict manufacturing controls. Certification protocols must adapt to evolving international MLs and promote industry adoption of validated mitigation practices.
Citation
Abt, E., & Robin, L. P. (2020). Perspective on cadmium and lead in cocoa and chocolate. Journal of Agricultural and Food Chemistry. https://dx.doi.org/10.1021/acs.jafc.9b08295