For as much as modern society worships chocolate, cacao -- the plant chocolate comes from -- was believed to be even more divine to ancient Mayas. The Maya considered cacao beans to be a gift from the gods and even used them as currency because of their value.
As such, cacao bean production was carefully controlled by the Maya leaders of northern Yucatan (Mexican state), with cacao trees only grown in sacred groves. But no modern researcher has ever been able to pinpoint where these ancient sacred groves were located -- until now.
During a recent study published in the Journal of Archaeological Science Reports, researchers at Brigham Young University, worked closely with archaeologists from the US and Mexico to identify locations the Maya used to provide the perfect blend of humidity, calm and shade required by cacao trees.
While the drier climate of the Yucatan peninsula is inhospitable to cacao growth, the team realized the vast array of sinkholes common to the peninsula have microclimates with just the right conditions. As detailed in the new study, the team conducted soil analyses on 11 of those sinkholes and found that the soil of nine of them contained evidence of theobromine and caffeine -- combined biomarkers unique to cacao.
Archaeologists also found evidence of ancient ceremonial rituals -- such as staircase ramps for processions, stone carvings, altars and offerings like jade and ceramics (including tiny ceramic cacao pods) -- in several sinkholes.
"We looked for theobromine for several years and found cacao in some places we didn't expect. We were also amazed to see the ceremonial artifacts,” said Richard Terry, BYU professor and senior author of the study.
To extract and analyze the sinkhole soil for cacao biomarkers -- specifically theobromine and caffeine -- the team developed a new method of soil extraction.
This involved drying the soil samples and passing them through a sieve, covering them with hot water, having them centrifuged and passed through extraction disks, and analyzing the extracts by mass spectrometry.
The findings of the BYU study indicate that cacao groves played an important role in ancient rituals and trade routes of the ancient Maya, impacting the entirety of the Mesoamerican economy.
