In Mexico, 1.5 to two million liters of nejayote are generated every day to process 600 tons of corn; that is, 1,500 to 2,000 cubic meters. An alternative to change the nixtamalization process to a sustainable one is the treatment and production of value-added products from this liquid, including poultry feed, food additives, etc.; however, these processes need to be scaled up to become a real solution to the problem.
Participating in the Permanent Seminar on Agriculture, Food and Sustainability, Martha Elena Domínguez Hernández, from the Faculty of Higher Studies Cuautitlán, stated the above and added:
An additional proposal is to implement a circular system for the generation of grain because circularity in agriculture establishes the elimination of waste and pollution. "If we integrate corn, animal, and agro-industrial productions such as flour, dough, and tortillas, we can have such a system."
It would be possible if we consider that 84 percent of the grain production units belong to small-scale farmers with less than five hectares and that the main destination of production is self-consumption. We have 109,830 tortilla and nixtamal mills, several of which are close to rural communities where grain cultivation takes place.
For example, the livestock system would provide the source of organic fertilization. Manure, improves soil fertility, increases moisture retention capacity, reduces erosion, and becomes an input for agricultural production, explained Domínguez Hernández.
According to studies carried out by the university, this type of fertilizer made with nejayote-manure increased corn yields by 1.3 tons, compared to conventional chemical fertilization, among other positive results.
Best practices in the corn industry
Currently, food production is based on a conventional approach in which industrial production systems seek to maximize yields and achieve short-term economic benefits, leaving aside the social and environmental aspects.
In conventional systems, production depends on the use of agrochemicals and external inputs such as fertilizers, but their inefficient use leads to the loss of biodiversity, contamination of bodies of water, resistance to pests, weeds, and diseases, and increased use of non-renewable resources. These practices also lead to the degradation of agricultural soils by reducing productivity and affecting the food security of producers, among other problems.
The scientist explained that the current traditional and commercial nixtamalization process is not considered sustainable due to the amount of water consumed and the waste it generates. Its waste liquid, called nejayote, is rich in corn solids and calcium; it is classified as a pollutant due to its chemical characteristics and the fact that it is disposed of in the sewage system without prior treatment, among other aspects.
Sustainable corn production
Mario Enrique Rodríguez García, from UNAM's Center for Applied Physics and Advanced Technology, based in Juriquilla, Querétaro, pointed out that tortillas are the main source of calcium in the Mexican diet. "Without them, the rates of osteoporosis and osteopenia would be sky high."
When we go to the bakery we find 100 types of bread; however, with tortillas that do not happen. "We have not evolved; this industry should be more developed, more sustainable," he said.
The nixtamalization process (which includes grains, in this case, corn, water, lime, and an alkaline thermal process), along with beer, is the oldest food transformation process there is. "It is difficult to understand and it is not sustainable because the physical and chemical transformations that the grain undergoes during the cooking stage are extremely complicated".
The first breakthrough was the creation of the tortilla machine, and the second was the production of flour. Today, "the ecological processes must consist of reducing the work for the women who dedicate themselves to this by 99 percent, and the nejayote by 100 percent".