According to The Nutrition Source, each corn kernel has three main parts: the germ, bran, and endosperm. Most of the starch in corn is inside the endosperm, which makes up the interior layer of the kernel, according to Purdue University. To make cornstarch, sometimes called maize starch, farmers first separate the bran, germ, and endosperm of corn kernels. Finally, the cornstarch is dried and packaged, and is therefore considered a highly processed food. Besides being a common food additive, cornstarch has many commercial uses, according to the Corn Refiners Association.