*Improving Field Corn (Maize) Vitamin Availability*
30 October 2017
Although corn to most Americans means sweet corn, large quantities of field corn are consumed as food for humans around the world. Field corn is usually referred to as maize in most of the world and this article will do the same in order to avoid confusion with sweet corn. Most maize used for human consumption is dried and preprocessed in some form rather than eaten like sweet corn. The nature of this preprocessing is important to the availability of important vitamins and plays a significant health role in societies heavily dependent on maize. Maize (sold as dried corn) is frequently found in a prepper's food inventory and is available from many sources. Details of preprocessing are very important if maize becomes a significant part of a hard-times diet.
Maize has been an important food product for centuries. Native populations of North and Central America cultivated maize long before Europeans arrived. Tortillas are a well known staple in Mexican cooking and grits (ground hominy) is a more recent development especially popular in the southeastern United States. These products are not created by simply drying maize and grinding the dried kernels into flour or meal. There are essential processing steps prior to using maize that make important vitamins available for use by the body.
A serious deficiency of niacin (vitamin B3) and/or tryptophan can result in the disease Pellagra. The symptoms of Pellagra include diarrhea, dermatitis and dementia; if untreated Pellagra usually leads to death. This disease is most common in parts of the world where maize is a primary food source. In the early 1900s Pellagra was widespread in poorer regions within some southeastern states in the USA. Pellagra can be treated and cured, but it can be avoided by proper preparation of maize prior to use.
Traditional preparation of maize in southwestern United States, Mexico and into Central America includes processing the kernels by boiling them in alkaline water, usually containing lime, followed by a long soak period in the liquid. In some areas sodium carbonate is used. After the soak period the maize is washed multiple times to remove the lime and hulls. This process is called nixtamalization; lime reacts with the maize kernel to make niacin more available to the body. Other benefits include improved protein quality, increased calcium content and the reduction of aflatoxin concentration of masa products.  After the maize is nixtamalized it can be ground and made into tortillas immediately, or dried and ground into masa for later use. Unground nixtamal can be used in dishes such as posole.
A similar method was used in the southeastern USA to prepare hominy to grind into grits. The main difference was the use of lye (potash) which was extracted from wood ash. Water was poured through wood ashes until the proper concentration was achieved, then filtered for use. After boiling and soaking in lye water, the processed hominy kernels were usually washed, dried, then ground into grits. Whole hominy can be used in similar manner to unground nixtamal. When this was done at home the processing was usually done outdoors in large cast iron kettles. Commercial processes have replaced small-scale home production of grits.
A study has shown the results of the two methods (lime vs. lye) to be similar, but with some differences when making tortillas. However, the authors note that "Although some differences were observed in the sensory studies, human subjects did not dislike the wood ash made tortillas." 
The author's analysis of the alkali liquid reveals:
"The Ca, K, Mg, Fe, and Zn content of lime and wood ashes showed lime to be high in Ca content while wood ash contained more K and about 71% of the Ca content of lime. Both contained relatively high levels of Mg, Fe and Zn, but more so in the wood ashes." 
There are disagreements as to the reasons underlying nixtamalization's reported ability to prevent Pellagra. A United Nations document provides the following comment:
"The alkaline treatment of maize has been reported to destroy its pellagragenic factor. Evidence from a large number of researchers has suggested that pellagra results from an imbalance of the essential amino acids, increasing the niacin requirement of the animal. This point has been extensively debated between those who claim that niacin in maize is bound and not available to the animal and those who favour the theory of improved amino acid balance induced by the alkaline-cooking process, as lime treatment results in release of the bound niacin." 
There is evidence people who depend on maize for a major part of their diet are at risk of developing Pellagra if the maize is not processed in alkaline water prior to consumption. While there may be disagreement on the exact mechanism by which nixtamalized maize helps prevent Pellagra, evidence suggests that it is effective. Nixtamalization was developed in pre-Columbian times, although the process has been adapted for large scale modern commercial use. The old processes once done on a small scale can be returned to service if maize constitutes a significant percentage of a hard-times storage-food diet.
 Effect of nixtamalization on the chemical and functional properties of maize, by Samuel Sefa-Dedeh, Beatrice Cornelius, Esther Sakyi-Dawson, Emmanuel Ohene Afoakwa original research article published in Food Chemistry, Volume 86, Issue 3, July 2004, Pages 317-324
Made available for download by Prof. Afoakwa through SelectedWorks at:
 Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics, by Pappa MR, de Palomo PP, Bressani R. Plant Foods for Human Nutrition, June 2010, Volume 65, Issue 2, pp 130-135
This article is not available online but an abstract is available at PubMed, US National Library of Medicine, National Institutes of Health http://www.ncbi.nlm.nih.gov/pubmed/20369297
 Lime-treated maize (part II), from Maize in human nutrition
Food and Agriculture Organization of the United Nations, Rome, 1992
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