Cadmium migration from nib to testa during cacao fermentation is driven by nib acidification

Previous work has shown that cacao nib cadmium (Cd) concentrations decrease during fermentation, but only when reaching sufficiently low pH. In this work, lab-scale experiments (5 kg units) with lactic and acetic acid amendments were ineffective at reducing the total Cd concentration. contrast, water-extractable fraction of concentration clearly increased pH was decreased. When single pod derived beans embedded inside a full-scale fermentation box to monitor effect high precision, decreased by factor 1.25 (P-value <0.05) after four days fermentation. Visualisation mobile gradient within LA-ICP-MS (using imprints transversal cuts exposed metal binding gel) revealed enhances mobility in nibs.