Physical and chemical changes undergone by pericarp and endosperm during corn nixtamalization-A review

Nixtamalization is the cooking of corn grains, traditionally in water with wood ashes or alkaline compounds. However, due to the pollution caused, the use of other calcium salts or weak acids, as well as alternative processes, has been explored. The pericarp and endosperm comprise 80.5-92.9% of the total weight of the grain and therefore have great effects on handling during processing and the quality of nixtamalized corn-based products. An introduction to nixtamalization processing conditions is followed by reviews of the microstructure and composition of the pericarp and endosperm, and the effects of nixtamalization on the structures and compositions of these tissues. In particular, the processing of raw corn into masa (dough) affects the gelatinization of starch, the interactions of starch with calcium and amylose-lipid complexes, with impacts on pasting properties and digestibility. Finally, the research required to underpin the development of new processing alternatives is discussed.