Corn grain is composed of endosperm (82-83%), germ (10-11%), pericarp (5-6%) and tip cap (0.8-1.0%).
The pericarp is the outmost layer that is characterized by high crude fiber content, mainly consisting of hemicellulose, cellulose and lignin. The pericarp protects the kernel and resists penetration by water. Endosperm contains approximately 87-88% of starch that consists of amylose and amylopectin.
The endosperm consists of a thin layer of aleurone cells containing oil an protein and a large inner portion of storage tissues containing starch and protein.
The germ is high in oil, protein, sugars, vitamins and minerals with little starch.
The aleurone is a single layer of cells in the pericarp that contain a larger proportion of oil, protein, minerals, ash, vitamins and enzymes that other cells.
The structure of corn
