Nutritional quality of nixtamal tortillas fortified with vitamins and soy proteins.

The nutritional qualities of nixtamal tortillas (TN) fortified with vitamins and soy flour was evaluated. The rats fed with TN and nixtamal tortillas with 0.15% of vitamins and iron (TNV) did not show differences in weights. The diets of fortified tortillas with 4% defatted soy (TNS), the combination of defatted soy and vitamins (TNVS) and the whole tortilla with defatted soy (TIS) were the treatments that caused the best growth in the experimental animals. The chemical analysis indicated appropriate levels of vitamins in the TNV, TNVS, TNS, and TIS diets. However, the TNV diet caused poor growth of the experimental animals. The diets of tortillas fortified with soy in general produced rats with longer femurs of greater density and strength. The rats fed with fortified tortillas showed higher levels of calcium and phosphorous in the bones. The X-ray diffractograms of bone tissue showed crystals with interplanar distances of 4.40, 3.34, 2.79, 2.28, 1.95, 1.85 and 1.45 A, which are characteristic of hydroxylapatite, except for the first two measurements. The peaks at 4.40 and 3.34 A tend to disappear as the nutritional quality of the diet improves with the addition of soy flour.