The spicy Mexican cuisine, which is one of the world's tastiest and most popular, may be nearly 1,500 years old, say scientists at the Smithsonian Institution.
Linda Perry of the Smithsonian's National Museum of Natural History says that as early as 1,500 years ago, Pre-Columbian inhabitants of southern Mexico enjoyed a spicy fare similar to Mexican cuisine today.
The new finding, published in the Proceedings of the National Academy of Sciences, is based on an analysis of plant remains from two caves in the region, which yielded 10 different cultivars of chilli pepper.
"This analysis demonstrates that chillies in Mexican food have been numerous and complex for a long period of time. It reveals a great antiquity for the Mexican cuisine that we're familiar with today," said Perry, the lead author of the study.
In the course of study, desiccated plant remains from excavations in Guila Naquitz and Silvia's Cave, two dry rock shelters near Mitla in the Valley of Oaxaca, were studied.
Guila Naquitz is famous for its well-preserved plant remains, dating back to the beginnings of squash cultivation in Mexico some 10,000 years ago. Arid conditions through the centuries prevented decay of the crop remains, which include corn, squash, beans, avocados and chilli peppers.
The study was focused on the two upper layers of ash and debris, known as Zone "A" and "Super-A," spanning the period circa A.D. 500-1500. Perry distinguished different cultivars among the abundantly preserved chilli peppers, a type of analysis that had not been completed on ancient Mexican chilies.
The researcher found that peppers from Guila Naquitz included at least seven different cultivars, while peppers from the smaller sample in Silvia's cave represented three cultivars.
Perry, however, is yet to confirm whether the cultivars found in the caves correspond to modern varieties, or whether they were types that died out after the arrival of Europeans in Mexico.
While one of them looks like a Tabasco pepper and another like a cayenne pepper, it is difficult to know how closely related they are to modern varieties without a genetic analysis, says the researcher.
"What was interesting to me was that we were able to determine that they were using the peppers both dried and fresh," Perry said.
"It shows us that ancient Mexican food was very much like today. They would have used fresh peppers in salsas or in immediate preparation, and they would have used the dried peppers to toss into stews or to grind up into sauces like moles," Perry added.
The researchers say that during the period circa A.D. 500-1500, the caves served as temporary camps and storage areas for farmers from Mitla, a major town on the river of the same name, whose cultivated fields evidently extended to the slopes of the piedmont below Guila Naquitz and Silvia's Cave.
"In the cave deposits, we can see excellent documentation for the sophistication of the agriculture and the cuisine at this point in time. You don't grow seven different kinds of chillies unless you're cooking some pretty interesting food," Perry said.