The cortex of corn consists of outer and inner chalk layers for peel, seed coat, and aleurone. Peel tissue is dense and shiny, with high fiber content. The seed coat is thin and tightly bound to the peel, making it difficult to separate. The pericarp and seed coat are commonly called corn husks, accounting for about 6% to 9% of the weight of corn kernels. The aleurone layer accounts for about 7% of the weight of corn kernels, has high nutritional content, 22.21% protein, and 6.93% fat content, and can be used as food. For example, if low-fat corn flour is extracted, it must be removed. Corn husk has high toughness and is not easy to break. Because it has a certain water absorption, it is easier to peel off after wetting with water.

The endosperm of corn is divided into keratin and silty. The hardness of horny endosperm is large and the hardness of powdery endosperm is small. Corn with high keratinization rate is not easily broken when peeled, and is suitable for making loquat and has high flour yield. Corn endosperm accounts for about 80% of the weight of the kernel.