Early Use of Chili in Mexico

Residues of chili pepper (Capsicum) have been found on pottery dating back 2000 years in southern Mexico, according to a study published in PLOS ONE.1 The New World Archeological Foundation (NWAF) first excavated the pottery (thought to date from 400 BCE–300 CE) from Chiapa de Corzo between 1955 and 1963.

Ultrahigh-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS–MS) was performed on residues collected from the pottery. Extracts were collected by lightly scraping the interior of 13 pieces of pottery with sandpaper, which were subsequently analyzed. Capsicum residues were identified in five out of the 13 pieces.

There has long been a connection between the fields of analytical chemistry and archeology leading to the development of molecular archeology, specifically when investigating the diet of ancient peoples. Lead author Terry Powis told LCGC: “I was asked by a Mexican colleague, Emiliano Gallaga, one of my co-authors, about two years ago to look for cacao in pottery vessels from the site of Chiapa de Corzo in the State of Chiapas. Although our focus was primarily to look for cacao in 2000-year-old pottery vessels from the site, we were also interested in looking for any additives or flavourings that may have been included in these particular drinks.”

The discovery of chili residues was an unexpected one, according to Powis. The vessels had been selected as cacao residues had been identified in similar artefacts in other areas. He said: “During the mass spectroscopy analysis we were completely surprised at the fact that no cacao was present in any of the pots tested. In fact, chili was present, although we have no way of knowing at present whether the amount is strong or weak, just that it is present.”

As an archeologist, the primary goal of Powis was to identify the exact species of chili pepper used but, as there are five different species, they were not able to determine this. He told LCGC that this is a future path, and that they are attempting to conduct DNA analysis of Theobroma cacoa on archeological samples to link residues to different modern species now in existence in different areas of the New World.

When discussing the importance of the work, Powis said: “Because of our findings we can now pursue many different cultural questions about how the Mixe-Zoque people used chili peppers in their daily social lives. We will also be able to move beyond its culinary use (but we still have a way to go) to include how they used it in pharmaceutical and ritual contexts as well.”

Reference
1. T.G. Powis, E.M. Gallaga, R. Lesure, R. Lopez Bravo, L. Grivetti, et al, PLoS ONE8(11), e79013 (2013).