Cocoa beans and derived products: effect of processing on polycyclic aromatic hydrocarbons levels

Abstract

Contamination of cocoa and its derived products by polycyclic aromatic hydrocarbons (PAHs) may occur due to high roasting temperatures and/or the presence of smoke during drying. Some PAHs are considered carcinogenic and genotoxic. Thirteen PAHs were investigated during cocoa processing. Two cocoa beans samples were used, with and without presence of smoke during drying. In both, an initial contamination was detected, 1.78 μg/kg for non-smoked beans and 66 μg/kg for smoked cocoa beans. After roasting, a decrease in contamination was observed. Levels detected in derived products were from not detected (shell) to 2.08 μg/kg (cocoa butter) for non-smoked beans and 5.2 μg/kg (cocoa powder) to 136 μg/kg (shell) for smoked beans. Mass balance showed that, for non-smoked cocoa beans, PAHs were transferred after pressing in equal proportions to cocoa butter (34%) and powder (37%). Smoked samples presented a large portion of PAHs in the shells (31%) and, after pressing, compounds remained mainly in the cocoa butter (43%). A tendency for PAHs to migrate to cocoa butter was observed. Drying cocoa beans without contact with smoke could reduce contamination and, therefore, human exposition to potentially carcinogenic and genotoxic compounds.