More than 50 varieties of maize exist, but are generally divided into five major categories: flint corn; dent corn; flour corn; popcorn; and sweet corn. Each of the varieties of maize is based on kernel size, color, and the amount of starch within each kernel. Popcorn and flour corn represent the two oldest varieties of maize used as food, and botanists believe all types of maize share a common origin.
Flint corn, also called Indian corn, grows in many colors, ranging from red to white kernels. It is mainly used as livestock feed or ground into corn meal because of its thick, outer shell covering a small, starchy center. Flint corn is similar to dent corn.
Dent corn is called field corn in some regions. As these varieties of maize dry out, the ends become dented. Dent corn is also used to feed livestock and ground into corn meal. It is also the variety converted into corn oil and corn syrup, and contains 4 percent sugar. Dent corn has emerged as a source of biofuel as concerns about the environment led to research on new fuel sources.
Flour corn consists mainly of starch covered by a thin outer shell. This is one of the varieties of maize used to create corn flour used in baked goods. Flour corn is easy to grind, making it an ideal source of flour. In the past, this type of corn was roasted until the kernels split open, exposing the soft interior. It could be stored for months without spoiling, making it a good source of nutrition during winter months.
Popcorn varieties of maize were used as early as 3600 B.C. by the Maya and Aztec civilizations. A soft center with ample moisture causes the kernel to explode when exposed to heat. Popcorn kernels are smaller than other varieties of maize, and come in rice or pearl types, defined by shape.
Sweet corn represents the most common type consumed for flavor, eaten right off the cob, canned, or frozen. This variety contains about 10 percent sugar that quickly converts to starch after harvesting. Historians estimate this type of maize has been cultivated since the late 1700s.
All varieties of maize prefer high summer temperatures to allow ripening. They require ample amounts of water during the growing period to flourish and produce high yields. The yield depends on soil conditions in the region where corn is grown. American Indians depended on maize for a form of bread that made up a large part of their diets. They also fermented corn into an alcoholic beverage similar to beer.
