What does Nixtamalization Mean?

Although niacin is present in maize (corn), only 20 to 50% of it is available in the free form. A major percentage of niacin in maize is bound up, hence not available for absorption.

When it comes to cooking corn, we often prefer to drop it in hot water until it starts boiling.

However, a healthier option would be to cook it using a process called nixtamalization. In this process, corn is soaked and cooked in limewater, which is an aqueous solution of calcium hydroxide. Limewater is an alkaline solution that has often been recommended for cooking corn.

Corn is generally considered nutritionally deficient but with nixtamalization, it can be transformed into a good source of nutrition.

Nixtamalization has been practiced for centuries by our ancestors. Mesoamerica (currently Mexico and central America) is credited for starting this process of nixtamalization. This method of cooking was an integral part of the early Mesoamerican diet.

Archaeological evidence suggests that this cooking method was practiced as early as 1200 BC in Guatemala.

The Native Americans commonly used sodium carbonate for making an alkaline solution. The ancient civilizations in Mexico such as the Mayans and the Aztecs practiced nixtamalization using slaked lime and ash (potassium hydroxide). The civilization native to Columbia used calcium hydroxide (cal) to nixtamalize corn.

The first step involves cooking dried corn kernels in an alkalizing agent such as limewater. When limewater reaches its boiling point, heating is continued for a few minutes to an hour. The kernels are then allowed to steep anywhere from a few minutes to up to 24 hours.

This is followed by decanting to separate the alkaline liquid from the kernel. The kernels are then rinsed properly. This is followed by hulling, which involves removing the hard portion of the kernel. What remains is the endosperm of the grain, which is commonly referred to as nixtamal.

Fresh nixtamalized corn is then grounded to corn flour (dough), which is commonly used for making tortillas, tortilla chips, tamales, pupusas, tlacoyos, and arepas. Hominy is made by the nixtamalization of dried maize kernels.

This method of cooking enhances the nutritional value of corn. As such, corn is a good source of niacin (vitamin B3). However, with nixtamalization, the bioavailability of niacin increases tremendously. To be more specific, in pre-treated corn, the niacin is attached to a large molecule, thereby inhibiting its absorption.

The alkalization of corn detaches niacin from the molecule. This unbound form of niacin can now be readily absorbed.

Since pre-treated corn is low in niacin, nixtamalization is particularly important when corn forms the staple food of the diet. Niacin deficiency has been responsible for causing pellagra, a condition that is typically marked by a thickened, rough skin.

Moreover, corn cooked in an alkaline solution has greater amounts of calcium than raw corn. Limewater being a good source of calcium, corn soaked in limewater readily absorbs this mineral. Hence, there can be up to 750% increase in the calcium content of corn that is subjected to the nixtamalization process.

Alkalinity also increases the availability of essential amino acids. Thus, more protein is available in nixtamalized corn.

Fusarium verticillioides, a fungus associated with corn is known to release mycotoxins such as fumonisin. These mycotoxins reportedly cause liver and kidney cancer in animals. However, nixtamalization strips maize off its mycotoxins, leaving it completely safe for consumption.

Studies show that there is a substantial decrease in the mycotoxin levels (up to 90 to 95% ) of corn treated with nixtamalization.

High levels of phytic acid in grains (corn included) have always been a cause of concern, as they considerably inhibit the absorption of essential minerals including calcium, magnesium, zinc, and iron. An easy way to resolve this issue is by nixtamalizing it. Nixtamalization can work wonders in reducing phytic acid levels of grains, in turn increasing the bioavailability of essential nutrients.

Nixtamalization imparts a wonderful taste to maize. The alkalization process ameliorates the flavor and aroma of corn. Nixtamalized corn tends to have a pleasing delicate nutty flavor. So apart from increasing the nutritional content of maize, the alkalizing agent is also effective in enhancing its taste.

Industrial methods do not use the traditional nixtamalization process for making tortillas. They instead opt for the enzymatic process of nixtamalization. This process is carried out at a much lower temperature (50-60 degrees Celsius) and the alkaline solution is added with protease enzymes.

Also, before alkalization, corn is pre-soaked in hot water so that the grain can easily absorb the enzymes. Moreover, corn is cooked for not more than 30 minutes in the alkaline solution.

This enzymatic process lowers the amount of corn wasted during processing and most importantly, the production time and cost reduces considerably. However, the resulting dough produced from the enzymatic process for making tortillas has a much lower nutritional value in comparison to that produced from traditional nixtamalization.