Maize products in Mexico are much healthier than local products and the secret has been known for centuries in the Americas. Since ancient time Aztec, Mayan and Mexican civilizations have developed a process of cooking maize that effectively softens the maize and improves the taste, and which unintentionally also ensured that more nutrients remained in the food.
When Portuguese “colonists” introduced maize in the 16th century in Africa, it became a major food crop over time, but lacked the healthy processing techniques of the ancient Aztec, Mayan and Mexican civilizations. Populations using untreated maize as their staple diet run the risk of malnutrition.
What is different about Mexican maize?
The Mexican way of preparing maize is called “nixtamalization” and it refers to the process in which the grain is cooked and steeped in an alkaline solution, usually limewater, and then washed and hulled before being used to prepare different types of food. These ancient civilizations developed the nixtamalization process by using slaked lime (calcium hydroxide) and ash (potassium hydroxide) to create alkaline solutions when cooking maize. This process offers a host of nutritional benefits when compared to “untreated” maize. (More on this later.)
The nixtamalization process:
- Whole corn – kernels of dried maize are used.
- Alkaline solution – the usual mixture in water is 15 ml of lime per 500g of maize.
- Cook – the maize is cooked in the alkaline solution at or near boiling point.
- Steep – after cooking, the mixture is steeped in the cooking liquid. The length of time for cooking and steeping depends on the type of food being prepared. During cooking and steeping chemical changes take place. Kernels soften and hulls loosen.
- Wash – after cooking the alkaline liquid is discarded and the kernels are washed thoroughly. The hulls are then (easily) removed, traditionally by hand at home or mechanically in industrial production.
- Nixtamal – the prepared maize is called nixtamal.
- Grind – the nixtamal is then ground into various degrees of coarseness, depending on use.
- Fresh dough – by adding water, ground fresh nixtamal is made into dough, for example to make tortillas.
- Dried four – dried and ground nixtamal can be used as flour and is called masa harina or instant masa flour.
Health benefits of nixtamalization
Nutritional benefits result from the chemical changes that take place in the grains of the maize, due to the alkaline processes.
- The kernels soften and hulls loosen, enabling the grains to hydrate and absorb calcium and/or potassium, depending on the type of alkaline used.
- Starches swell and gelatinize and some starches get absorbed in the cooking liquid, and are later discarded.
- Cooked grains can be ground more easily.
- Dough can easily be made from the nixtamal, while cooked untreated maize is unable by itself to form a dough when adding water.
- Proteins and nutrients from the endosperm of the kernel are more readily available to the human body.
- The amount of the protein zein is reduced, improving the balance of essential amino acids. Although the overall amount of protein is reduced, bonding of the proteins to each other is facilitated.
- The bound niacin in maize is converted to free niacin, facilitating absorption into the human body.
- Minerals from the alkali is absorbed in the maize, increasing calcium, iron, copper, and zinc levels in the human body.
- Mycotoxins produced by mold commonly found in maize is drastically reduced (by 90%).
- Flavour and aroma are improved.
Early in October 2016 a group of Mexican maize specialists, with a view of sharing the Mexican maize preparation techniques, have been meeting in South Africa with representatives from the Agricultural Research Council, the University of Pretoria, maize associations and various government departments. Who knows if this may ultimately result in the “decolonization” of our local maize products?
Sources of information:
“Mexico brings its secrets to SA” The Star. 7 October 2016. Published online 09:10 am.