Beheer van cadmium concentraties in Latijns-Amerikaanse cacao: analytische uitdagingen en na-oogststrategieën voor mitigatie

Cacao from Latin America contains high concentrations of cadmium (Cd) that originates from the high natural Cd background concentration in soils of that region. The 2019 regulations by the European Union have set a stringent limit for Cd in chocolate. It is estimated that about half of the Latin American production exceeds this limit. Similar limits recently went into effect for nickel (Ni) on 1 July 2025. The lack of standardized sampling protocols and high variability among local laboratories introduces substantial uncertainty, particularly since these regulations require highly sensitive and accurate trace metal detection. This PhD provides novel insights into the monitoring and mitigation of Cd in Latin American cacao. First, the main sources of error in current monitoring practices were identified, and practical guidelines for representative bean sampling were developed. A portable X-ray fluorescence (XRF) setup was validated as a low-cost and rapid screening tool for Cd in beans and soils, offering strong agreement with laboratory-based methods. Additionally, three predictive modeling approaches were evaluated to assess land suitability for cacao expansion. Digital mapping combined with local soil sampling proved promising for identifying suitable areas at a logistical cluster scale. The second part of this work explored post-harvest strategies to reduce Cd and Ni concentrations in fermented beans. Soaking beans in water or salt solutions showed significant, but weak and variable reductions of bean Cd and Ni concentrations, with greater removal observed in ground material and enhanced extractability for Cd using magnesium chloride. Importantly, short-duration soaking did not affect sensory charactersitics of cocoa liquor or dark chocolate. Together, these findings contribute a practical framework to help the Latin American cacao sector comply with international food safety regulations, while supporting sustainable growth and market access.