Physical and chemical characteristics of industrial nixtamalized maize flour for human consumption in Central America.

The objective of this study was the characterization of industrial nixtamal ized maize flour for human consumption and which are marketed in Central Am erica for some selected physical and chemical properties which may contribu te to food composition information and help nutrition and micronutrient for tification programs. A total of 12 brands purchased in triplicate were obta ined from super-markets in Guatemala, El Salvador and Honduras. These sampl es were kept under refrigeration until analyzed. The physical parameters me asured and results were the following: particle size with most samples havi ng a high percentage of particles greater than 60 mesh, pH (5.4-7.5), water absorption index (WAI) (3.4-4.0 g gel/g sample), water soluble index (WSI) (4.8-7.8 g/100g) and flour density (0.410-0.547 g/ml). The differences wer e statistically significant for all parameters measured, except for WAI. Th e chemical characteristics included, moisture, protein, fat, ash and dietet ic fiber. Differences between flour samples were statistically significant except for fat content. Protein content was low, ranging between 6.7-8.1 g/ 100g and total dietary fiber varied between 7.7-12.0 g/100g. The samples we re analyzed for phytic acid with a variation from 632 to 903 mg/100 g, with statistical significant differences. The samples were also analyzed for to tal and soluble (pH 7.5) iron, phosphorus, calcium, potassium, zinc, copper , manganese, and magnesium. The difference in the iron and calcium content between flour samples were statistically significant. The physical and chem ical variability found between flour samples of nixtamalized maize was rela tively high and it is recommended to establish quality standards through ra w material and process standardization for greater effectiveness of nutriti on programs and activities on micronutrient fortification which may be purs ued in the future.