November 14, 2007

Also appeared in print Nov. 19, 2007, p. 11

Archaeology

Cacao Drinks Date To 1150 B.C.

Analysis of pottery residue shows chocolate plant used earlier than anthropologists realized

Jyllian Kemsley

Chocolate, made from cacao beans, was once the currency of the Aztec empire and continues to be a luxury commodity. Anthropologists are still unsure, however, of when and how cacao-based beverages originated in the region now known as Central America. A group led by John S. Henderson, a professor of anthropology at Cornell University, has found the cacao component theobromine in pottery dating back to 1150 B.C., about 500 years earlier than previously documented (Proc. Nat. Acad. Sci. USA, DOI: 10.1073/pnas.0708815104).

The researchers collected pottery samples at excavation sites near the village of Puerto Escondido, Honduras. In prior studies, only visible residue remaining inside pottery was analyzed. In the latest work, the researchers extracted residues from the aluminosilicate matrix of pottery fragments by heating the pieces in water, methane/methanol, or chloroform/methanol. They analyzed the extracts using liquid chromatography and gas chromatography coupled to mass spectrometry.

Although theobromine was detected in the early pottery, missing were additives commonly reported in other ancient, though more recent, chocolate drinks, such as compounds from beeswax in honey or capsaicin from chili peppers. These results, along with the style of the pottery (shown), led the researchers to hypothesize that the early beverage was actually a fruit wine made from fermenting cacao pulp and that the practice of using cacao seeds for chocolate drinks developed later.

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