Controlling cadmium uptake in cocoa beans

Using genetic techniques to prevent cadmium accumulation in cocoa 

Lead researcher: Prof David Salt

In January 2019, the EU introduced new regulations on the permissible limits of cadmium in chocolate and cocoa powder. Cocoa beans from Latin America and the Caribbean are known to contain higher concentrations of cadmium, and efforts are being made to try and reduce this cadmium. This is not a problem for farmers selling to the bulk cocoa market, where beans from multiple places are blended. But this does pose a problem for farmers looking to sell to the fine-flavour market with single-region cocoa. 

This project will identify natural genetic variation in cadmium accumulation in cocoa beans, and will identify rootstocks with a tendency to exclude cadmium. This will allow farmers to choose cocoa trees which naturally lower the amount of cadmium in the beans. It will also allow them to graft low cadmium rootstock onto shoots from trees that produce their best quality cocoa beans in order to lower the levels of cadmium in these beans.

This project is in partnership with the Cocoa Research Centre, University of the West Indies, Trinidad and Tobago.