Nixtamalization products

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. 

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. 

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. 

FIGURE 9.3 Equipment commonly used for the industrial production of table tortillas, (a) Open cooking vessel (courtesy of Casa Herrera, Inc.), (b) Vertical cooker, (c) Nixtamal washer (courtesy of Heat and Control, Inc.), (d) Commercial stone grinder. 

The rapid and exponential growth of the production and sales of lime-cooked snacks took place mainly during the last decade of the twentieth century. These snacks rapidly became popular in other areas of the world as well. Today, corn and tortilla chips are manufactured worldwide. Flat tostadas and tortilla chips are tortillas that are deep-fat fried they are widely used as snacks or vehicles for the preparation of fast foods. For their preparation, nixtamal and red-paprika peppers or annatto are stone-ground into a coarse masa. The red- or orange-colored masa is baked into a tortilla and then fried into a tostada. Tostadas are the base for the preparation of a wide array of meals. Sometimes, they are eaten as a snack with lemon juice and sauces. It is very common to consume tostadas with refried beans, cheese, shredded meats, and vegetables such as lettuce, tomato, onions, peppers, and radish. Taco shells are the American version of tostadas, the only difference being that they are usually fried bent (U form) and rarely colored. 

The nixtamal pH correlates to the lime absorbed during cooking and steeping, and the amount of washing. The pH affects flavor, texture, and color of processed products. 

Lime A white alkaline powder composed of calcium oxide or hydroxide used for the production of nixtamalized tortillas and related snacks. 

Masa Name of the ground nixtamal or lime-cooked maize that has cohesive properties. The nixtamalized masa is the backbone for the production of table tortillas, corn chips, tortilla chips, and other traditional food items widely consumed in Mexico and other Latin American countries. 

Description of industrial milling systems, and chemical composition and characteristics of dry-milled, wet-milled, and nixtamalized or lime-cooked products... 

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