Nixtamalization: A Tortilla a Day Keeps the Doctor Away

Today is National Taco Day, and although I must admit that I neglect most of these “para-holidays” this occasion happens to intersect with one of my passions: Meso-american History.



My interest in tacos, however, is focused on one particular, indispensable ingredient: tortillas. Tortillas are important: they may have saved the lives of millions in the last 5,000 years. How so? Well, it all has to do with how the corn is prepared in the Tortilla-making process.

Corn has been a staple crop in Mesoamerica for at least 5,000 years. Earliest evidence of its domestication dates back 8700 years . It can be planted on steep hillsides, in semi-arid rocky environments, in very hot places, and in pretty cold places. The resilience of corn has made it indispensable in the highly variable terrain and climate of Mesoamerica. The only problem is that corn is naturally low in a chemical called niacin, and the low levels that are present in corn are chemically bound.

Niacin is important to many chemical processes in the body. Severe Niacin defficiency is called Pellagra, and has some nasty side effects. Known as the “three D’s”, the symptoms include dermatitis, diarreah, and dementia. Pellagra was reported in low-income populations throughout the American South and in parts of Europe in the late Nineteenth Century, after corn began to spread to areas outside of Meso-america as a cheap and low maintenance food source. 

Interestingly, Pellagra was not reported as commonly in Mexico, even though a large, rural peasant population, dependent on corn for their diet, persisted. Why is this so? Tortillas! Tortillas require corn to be ground to a very fine consistency, to achieve this it was ground by hand in metates (stone grinders) up until the late nineteenth century, and is still partially hand ground sometimes today. 


In preparation for the laborious process of grinding the corn, the kernels would be soaked in a lime solution (not the fruit lime, but the calcium oxide kind) to soften them up. The resulting, softened mix is called nixtamal, and it has been essential to the tortilla making process for thousands of years. Unknown to the ancients, though, was the fact that the alkaline solution that broke down the cell walls of the kernels also released the niacin chemically bound inside those cells. 

So, while other cultures were struggling to adapt their diets to this miracle crop (corn is now the most abundant crop in the world, thanks to its resilience) the people of Meso-america were enjoying the delicious and nutritious treat inherited from their ancient ancestors. Even today, their descendants still do!mano-and-matate1

100 Years – 100 Objects: Pre-Columbian figurine fragments

The Houston Museum of Natural Science was founded in 1909 – meaning that the curators of the Houston Museum of Natural Science have been collecting and preserving natural and cultural treasures for a hundred years now. For this yearlong series, our current curators have chosen one hundred exceptional objects from the Museum’s immense storehouse of specimens and artifacts—one for each year of our history. Check back here frequently to learn more about this diverse selection of behind-the-scenes curiosities—we will post the image and description of a new object every few days.

This description is from Dirk, the museum’s curator of anthropology. He’s chosen a selection of objects that represent human cultures throughout time and around the world, that we’ll be sharing here – and at – throughout the year.

Pre-Columbian figurine fragments - fourThis collection of ceramic figurine fragments was chosen because it illustrates the problem many museums face. What do we want to display? What do we want to collect?

In most cases, the answer will be “museum quality” pieces, which often translates into “pristinely preserved.” While there are a good number of high quality pieces out there, there are many more that are broken. That is what we see here.

These imperfect reminders of a past are no less important than an intact piece. For one, as is the case here, the sheer volume of figurine fragments from Mesoamerica tells us that they were abundant. What were they used for? Where do we find them? How were they made? Even broken artifacts like these can give us some answers. For this reason alone, they are treasured given a spot on our virtual exhibit.

Explore thousands of years of Native American history in the John P. McGovern Hall of the Americas, a permanent exhibition at the Houston Museum of Natural Science.

You can see more images of this fascinating artifact – as well as the others we’ve posted so far this year – in the 100 Objects section at