New study pushes back the origins of chocolate

While Halloween party goers are getting ready to eat chocolate, a new study by an international team of researchers, including the University of British Columbia, is pushing back the origins of the delicious sweet treat.

The study, published online today in Nature Ecology & Evolution, suggests that cocoa – the plant from which chocolate is made – has been domesticated or grown by humans for food, about 1,500 years earlier than expected. In addition, researchers found that cocoa had been domesticated in South America rather than in Central America.

Archaeological evidence of the use of cocoa dating back as far back as 3,900 years ago had already planted the idea that the cocoa tree had been domesticated for the first time in Central America. But genetic evidence showing that the greatest diversity of cocoa and related species are found in equatorial South America – where cocoa is important to contemporary indigenous groups – has led the UBC team and its colleagues in search of evidence of the plant on an archaeological site in the area.

"This new study shows us that people in the upper Amazon basin, extending to the foothills of the Andes in southeastern Ecuador, were harvesting and consuming cocoa, which seems to be a close relative to the type of cocoa used later in Mexico – and they did it 1,500 years ago, "said Michael Blake, co-author of the study and professor at the Department of Anthropology of Mexico. University of British Columbia. "They also used elaborate pottery that was earlier than found in Central America and Mexico, suggesting that the use of cocoa, probably as a drink, was something that farmers who grew cocoa tended to take and most likely spread north, which is now Colombia and finally Panama and other parts of Central America and southern Mexico. "

Cocoa Theobroma, known as cocoa, was a culturally important crop in pre-Columbian Mesoamerica – a region and cultural region historically North American that stretches from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua and North Rica. Cocoa beans were used both as currency and to make chocolate beverages consumed at parties and rituals.

For this study, researchers studied ceramic artifacts from Santa Ana-La Florida, Ecuador, the oldest known site of Mayo-Chinchipe culture, occupied for at least 5,450 years.

Researchers used three data sources to show that Mayo-Chinchipe cultivation used cocoa between 5,300 and 2,100 years ago: the presence of cocoa-specific starch seeds inside containers ceramic and broken pieces of pottery; residues of theobromine, a bitter alkaloid found in cocoa but not in its wild relatives; and old DNA fragments with sequences unique to cocoa.

The results suggest that Mayo-Chinchipes domesticated cocoa at least 1,500 years before the use of the crop in Central America. With some artifacts from Santa Ana-La Florida having links to the Pacific coast, the researchers suggest that merchandise trade, including plants of cultural significance, could have begun the journey of cocoa to the north.

Sonia Zarrillo, lead author of the study and assistant professor at the University of Calgary, who did some of the research as a lecturer in the department of anthropology at UBC Okanagan, said that the results of this study constituted a methodological innovation in anthropological research.

"For the first time, three sources of independent archaeological evidence have documented the presence of ancient cocoa trees in the Americas: starch grains, chemical biomarkers, and old DNA sequences," she said. declared. "These three methods combine to definitively identify a plant that is notoriously difficult to locate in archeological archives because seeds and other parts are rapidly degrading in humid and warm tropical environments."

Discovering the origins of the foods we rely on today is important because it helps us understand the complex stories of who we are today, Blake said.

"Today, we all depend, to one degree or another, on food created by the indigenous peoples of the Americas," Blake said. "And one of the world's favorites is chocolate."

Explore further:
The analysis of cocoa dates from the dawn of the domestic chocolatiers 3,600 years ago

More information:
Sonia Zarrillo et al, The use and domestication of Theobroma cacao during the Middle Holocene in the Upper Amazon, Nature Ecology & Evolution (2018). DOI: 10.1038 / s41559-018-0697-x