Effect of Micronutrient Fortification on Nutritional and Other Properties of Nixtamal Tortillas

Abstract

Nixtamalization is the process of steeping dried corn in hot water with calcium hydroxide (lime) with subsequent removal of all or most of the pericarp through washing. The resulting product is called nixtamal. Approximately 60% of corn tortillas in Mexico are produced from nixtamal, with the remainder prepared from nixtamalized corn flour. Nixtamal was fortified with micronutrient premix containing iron, zinc, folic acid, niacin, riboflavin, and thiamin. Premix composition followed a proposed Mexican regulation for corn flour fortification, adjusted for moisture. Effects of premix on masa adhesiveness, hardness, and pH, as well as tortilla sensory properties, stretchability, rollability, and color were measured. Micronutrient levels were tested in the dry corn, nixtamal, masa, and tortillas. There were no significant differences in masa texture or pH, tortilla rollability, or consumer acceptance of tortillas when comparing unfortified control and fortified treatments. Added thiamin was almost entirely degraded during processing. Folic acid and riboflavin decreased 26 and 45%, respectively, through the masa‐tortilla manufacturing process. Niacin showed no significant loss. Despite processing losses, fortification resulted in significant nutrient increases compared with control tortillas. Folic acid increased 974%, riboflavin increased 300%, niacin increased 141%, iron increased 156%, and zinc increased 153% in fortified tortillas.

Stability of Native Folate and Added Folic Acid in Micronutrient‐Fortified Corn Masa and Tortillas

“…This result also agrees well with other studies that show the stability of folate through the baking process. Burton et al (2008) and also found no loss of total folate in the masa during the tortilla baking process. Gujska and Majewska (2005) found a loss of 12-21% of added folic acid but found no loss of endogenous folate during baking for 30-40 min.…”

“…One important process variable present in the mill but not in the laboratory was the grinding step. However, Burton et al (2008) also passed fortified nixtamal through volcanic mill stones and observed only a 6% loss of folic acid through the grinding process. No similar process step was used in the laboratory study with CMF.…”

Predicted contribution of folic acid fortification of corn masa flour to the usual folic acid intake for the US population: National Health and Nutrition Examination Survey 2001–2004

“…For most of the foods identified and analyzed, the entire grain component was listed as nonwhole grains. For purposes of this analysis, corn masa flour was considered a non-whole-grain based on its manufacturing process, called nixtamalization-a process that involves steeping dried corn in hot water and exposing it to calcium hydroxide or lime (17). This process hydrolyzes the pericarp and removes it from the grain.…”

“…This process hydrolyzes the pericarp and removes it from the grain. The aqueous solution is then drained, and the remaining nixtamal is washed several times, removing seed coats, tip caps, excess lime, and any other impurities (17,18). It was assumed that most identified food products would use corn masa flour as the major flour or grain ingredient, thus making the non-whole-grain component a reasonable proxy.…”

Modeling fortification of corn masa flour with folic acid: the potential impact on exceeding the tolerable upper intake level for folic acid, NHANES 2001–2008

“…For the majority of foods identified and analyzed, the entire grain component was listed as non-wholegrain. For the purpose of this analysis, corn masa flour was considered a non-wholegrain based on its manufacturing process, called nixtamalization (22). There were several foods reported in 2003–2004 that were not listed in the MyPyramid Equivalents Database version 2.0 ( n =3); for these foods, the non-whole wheat grain component was estimated using the data from MyPyramid Equivalents Database version 1.0 (2001–2002).…”