Our Members Asked:
The distributor of my cacao powder says it checks for "metal fragments" in its products. Is this adequate to check for heavy metals, like cadmium and lead, that you've found in cocoas and chocolates?
No. What that company is describing has nothing to do with detecting elemental metal contamination (as we do) or removing that contamination. The company is describing the way they detect relatively large metal fragments that may be introduced during processing. Such fragments would then, typically, be removed by sifting.
As shown in our Dark Chocolate, Cocoa Powder and Nibs Review, heavy metal contamination is very common in cocoa and cacao powders and some dark chocolates. This contamination (typically with cadmium and/or lead) is not due to metal fragments but, most likely, the absorption by cocoa plants of metals in their environment (likely from pesticides and/or volcanic soil). Unfortunately, the levels of cadmium found are often very high -- suggesting that intake should be limited, and it does not seem possible to selectively remove these metals.
For information about how to choose the best quality cocoa powder and dark chocolate with the least contamination see Getting cocoa flavanols without contaminants and our Top Picks among products in the Dark Chocolate, Cocoa Powder and Nibs Review.