Physical and milling properties of maize

This chapter discusses the maize production in the world is mostly attributed to the development of technology and the seed industry, increased agro-efficiency, innovative maize food, and technical maize products, and, principally, innovation and increased production of bioethanol and biodiesel. The physical properties of maize grains are a group of important quality attributes, in addition to the chemical composition and cellular structure of the grains. Besides the proportion of glassy versus floury endosperm, hardness is also affected by the endosperm cell structure and pericarp thickness. Cellular compactness, cell sizes, and cell wall thickness all affect the kernel hardness but the most important is the endosperm cell structure: starch granules are surrounded with continuous protein matrix which is thinner and weaker in floury endosperm. Density is defined as a ratio of weight and volume and expresses the weight of unit volume i.e. specific weight. It is expressed as bulk density or true density