**1. Introduction**

Phenolic compounds are widely distributed in plants as products of their secondary metabo‐ lism; they are produced during plant development and some are of vital importance for their adequate functioning and interaction with the environment while others are synthesized in

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

response to stress conditions such as infections, injuries, ultraviolet radiation, among others [1, 2]. Furthermore, phenolic compounds serve as defense mechanisms since many of them display antifeedant and antipathogenic properties [3], which contribute to their adaptation to different environments. The presence of phenolic compounds in different plant foods contrib‐ utes to their distinctive characteristics and to its flavor and color. They can be found in solu‐ ble/free and bound/insoluble form. In maize grain the highest amount of phenolics (98.9%) is present in the insoluble fraction, and the remainder in the soluble fraction [4]. However, it is the soluble fraction that shows the greater chemical diversity, which depends on the color of the grain. The goal of this document is to provide a review of the various phenolic com‐ pounds present in maize grains of different colors, and the changes that occur when the grain is subject to nixtamalization processing for the elaboration of tortillas and all the diversity of nixtamalized products consumed in Mexico and in many other parts of the world.
