Discrimination of Cocoa Bean Origin by Chocolate Polyphenol Chromatographic Analysis and Chemometrics

摘要

Nowadays, the traceability and origin authentification in foodstuff is of great interest for consumers and industries. It is proved that the chemical composition is linked to the geographical and varietal origin of food products. Cocoa, the main ingredient in chocolate, provides a lot of polyphenol compounds still present in the chocolate bars. By analyzing these chemical species, we aim to investigate the information about the country of origin of chocolate. Our method is based on an acetone/water liquid/liquid extraction coupled with a high-performance liquid chromatography-diode array detector-mass spectrometry analysis (HPLC-DAD-MS). Forty-seven chocolate samples of different varieties (Criollo, Trinitario, Nacional, and Forastero) from 12 countries within two continents were analyzed. Polyphenols such as catechin, epicatechin, and several of procyanidins' polymers were identified. Principal component analysis (PCA) was performed on 21 variables: 20 polyphenols and the polyphenol total content. The results highlight that the polyphenolic profile allows to classify the chocolate samples according to geographical origins (Madagascar, Caribbean, different countries from South America and Africa) as well as their variety.