The Kernel of Wheat
sometimes called the wheat berry; the kernel is the seed from which the wheat plant grows. Each tiny seed contains three distinct parts that are separated during the milling process to produce flour.
Endosperm
This is about 83 percent of the kernel weight and the source of white flour. The endosperm contains the greatest share of protein, carbohydrates and iron, as well as the major B-vitamins, such as riboflavin, niacin and thiamin and folic acid. It is also a source of soluble fiber.
Bran
Bran is about 14 1/2 percent of the kernel weight. Bran is included in whole-wheat flour and can be bought separately. The bran contains dietary fiber, a small amount of protein, significant quantities of vitamin E, B-vitamins, minerals, antioxidants, and phytochemicals.
Germ
The germ makes up about 2 1/2 percent of the kernel weight. The germ is the embryo or sprouting section of the seed, often separated from flour in the milling because the fat content (10 percent) limits flour’s shelf life. The germ contains minimal quantities of high protein and a greater share of B-complex vitamins and trace minerals. Wheat germ can be purchased separately and is part of the sole wheat flour.