Nixtamalization Effects on the Contents of Phytic Acid, Calcium, Iron and Zinc in the Whole Grain, Endosperm and Germ of Maize

This article describes the effect of the nixtamalization process on phytic acid, calcium, iron and zinc contents in 11 varieties of whole maize and their germ and endosperm. Maize samples were cooked in water with 1.2% lime for 75 min at 96 °C, soaked for 10 h and washed. Half of the whole cooked kernel was dried and the other half was dissected into germ and endosperm, which were also dried. These samples were analyzed for phytic acid, calcium, iron and zinc. The germ contained the highest concentration of phytic acid and the endosperm the lowest. Phytic acid in the whole grain, endosperm and germ decreased upon nixtamalization. The loss in whole grain varied from 4.4 to 27.9%; from 19.7 to 59.8% in the endosperm and from 8.0 to 35.3% in the germ. Significant statistical differences were found for varieties, processing and for their interaction (varieties x processing). Calcium was present in higher amounts in the germ before and after nixtamalization. This process increased the level of calcium about 18 times in the whole grain and the endosperm, and about 24 times in the germ. The differences were significant due to variety, processing and their interaction (variety x processing). The germ contained higher amounts of iron in both its raw and nixtamalized states... (A)