Nixtamalization

Most manufacturing processes do not detoxify aflatoxin and therefore if the aflatoxins are not detected, products will be marketed. One of the processes used for reducing aflatoxin levels is nixtamalization (alkaline cooking), which is used during the making of corn tortillas, tortilla chips, and corn chips, and gives a 51 to 78% reduction in aflatoxin levels (Torres et al., 2001). 

Dombrink-Kurtzman, M. A., Dvorak, T.J., Barron, M. E., and Rooney, L. W. (2000). Effect of nixtamalization (Alkaline cooking) on fumonisin-contaminated corn for production of masa and tortillas. J. Agric. Food. Chem. 48(11), 5781-5786. 

Palencia, E., Torres, O., Hagler, W., Meredith, F. I., Williams, L. D., and Riley, R. T. (2003). Total fumonisins are reduced in tortillas using the traditional nixtamalization method of Mayan communities. ]. Nutr. 133,3200-3203. 

Figure 3. The 18 corn varieties used to study the nixtamalization process. Variety names correspond to those indicated in Table TV.

Calcium Content of Starch Isolated from Lime-Treated Corn. Starch is the major component of the corn grain and derived products (see Table VII). To explore in more detail the distribution of calcium after the nixtamalization process, calcium was measured in starch isolated from untreated and lime-treated com. These analyses (see Table VIII) indicated that calcium was fixed or bound in some way to the starch. There was approximately 2.9 times more calcium in starches isolated from lime-treated corns than in starches isolated from untreated grains. Figure 7 shows micrographs of isolated starches. 

The Requirement of a Divalent Alkaline Earth Metal. Lime-treated corn produces a dough whose functional properties depend on the pasting characteristics of starch. The hydroxides of different alkaline earth metals were tested to determine whether they could replace calcium in the nixtamalization process. It was not possible to prepare tortillas with adequate sensory or mechanical properties from corn treated with... 

The concentration of lime used in the nixtamalization process is ten times in excess of the saturation point. After cooking and steeping, about 40% of the original calcium ion remains in the lime water suspension. Of the 60% of calcium removed, about one-third is associated with the... 

We have observed that the same mechanical properties of doughs prepared from lime or calcium hydroxide-treated corn were achieved when com was treated with magnesium hydroxide. It seems reasonable to consider that the elaboration of products from nixtamalized corn is based mostly on the physical-chemical changes occurring in the starch component of the com grain. This is substantiated further by the fact that other starchy foods can be lime treated to yield products similar to those obtained from com. 

A further beneficial feature provided by the alkaline medium during the nixtamalization process is the destruction of aflatoxins in com contaminated by Aspergillus flavus (25). 

Waliszewski, K. N., Estrada, Y., Pardio, V. (2004). Sensory properties changes of fortified nixtamalized com flour with lysine and tryptophan during storage. Plant Foods for Human Nutrition 59 51-54. 

Aflatoxins in pozol, a nixtamalized, maize-based food. International Journal of Food Microbiology, 94, 211-215. 

American natives knew that corn needed to be processed to be nutritious in a process known nixtamalization (alkaline treatment commonly used in Mexico and Central America in the preparation of tortillas, tamales and hominy) or ingested as immature ears. This knowledge was lost when Christopher Columbus returned from the New World with samples of the new seed. 

Formulated with nixtamalized com flour Optical brightener... 

The alkaline cooking or nixtamalization of whole maize has become important in the United States and other parts of the world dne to the increase in popularity of Mexican foods. Three basic types of prodncts are indnstrially produced from alkaline or lime-cooked maize table or soft tortillas, com chips, and tortilla chips (Sema-Saldivar et al. 1990). Corn and tortilla chips are primarily produced and con-snmed in developed countries, where they have an important share within the salted snack food market, whereas table tortillas constitnte the staple food for large groups of people in developing Latin American countries. These prodncts can be produced... 

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