The elemental composition of chocolates is related to cacao content and origin: A multi-element fingerprinting analysis of single origin chocolates

摘要

Commercially available single origin chocolates (n = 139) were analysed by ICP-MS to identify the potential of elemental fingerprinting for tracing cacao origin in chocolate and to compare chocolate composition relative to trace metal limits. Cadmium (Cd) concentrations exceeded the EU limit of 0.80 mg kg(-1) in 16 samples, all produced with cacao from South or Central America. Six samples contained lead (Pb) concentrations > 0.10 mg kg(-1), the limit of the Codex Alimentarius for edible fats. Increasing cacao content was associated with increased element concentrations for most elements, indicating cacao as the main source of minerals and trace elements. Significant differences in elemental composition between origins (P value = 0.05) were found for Ba, Cd, Mo and Sr. Classification and regression tree analysis (CART) resulted in a decision tree that could effectively classify chocolate samples by cacao origin continent (overall misclassification rate 23%) based on the concentrations of five elements (Ba, Cd, Mo, Sr and Zn). Samples of South America were classified based on their Cd concentration, indicating the geogenic origin of Cd.