Generally plants are excellent at removing metals from the environment and concentrating them in different tissues, depending on the species and metal. Poplar t

Generally plants are excellent at removing metals from the environment and concentrating them in different tissues, depending on the species and metal. Poplar trees, for example, have often been used for remediation of Mercury contamination of souls Not sure about the specifics of cocoa, but not beyond the pale to see cadmium, for example, be concentrated in the beans. As for removal from food stuffs, it really depends on how the metals are bound to the plant material. Could be as simple as heating up in a vat with agitation, to requiring something so drastic it changes the nature of the chocolate. Best way is to reduce the amount that can be integrated by the plant, but good luck with that. The farmers would probably have to import heavy-metals reduced soil