A large fraction of the cocoa industry currently suffers from traceability issues. This is problematic because the quality of a finished chocolate product is highly dependent on the growing conditions of the cocoa beans and the manufacturing processes employed. Improving traceability in the cocoa industry would encourage the production of higher-quality cocoa products. This project sought to determine whether trace elemental signatures could be used to discriminate single-origin cocoa liquors based on country of origin. Cocoa liquors from eleven countries within Asia Pacific, Africa, Caribbean, and the Americas were studied. Eight replicate samples of each cocoa liquor were prepared and analyzed by inductively coupled plasma mass spectroscopy (ICP-MS). The resulting trace elemental data were analyzed using the discriminant analysis function in SPSS. This method was able to correctly identify the cocoa liquor samples by their country of origin using a cross-validation procedure. The following three questions were investigated: 1) Do cocoa liquor samples from the same country have different chemical signatures due to the different roasting and processing conditions (roast temperature, roast time, etc.) they undergo? 2) Can cocoa liquor samples from multiple countries be distinguished from each other using elemental signatures? 3) Which elements are most useful in creating a trace elemental signature for cocoa provenance determination? The results of this project indicate that cocoa liquors from eleven countries in the aforementioned regions can be distinguished by trace elemental signatures. It appears that differences in roasting conditions between cocoa liquors have minimal influence on the signatures, which indicates that the signatures are distinctive for each country. Future work will involve analyzing samples from more countries and combining elemental data with LC-MS data to create a more robust chemical signature. The ability to further classify cocoa liquors by geographic regions within a given country will also be explored.

Cocoa liquor provenance determination using trace elemental signatures

253rd National Meeting (2017)

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