Definition of Wheat Germ (by LIVESTRONG.COM)

Info Source: http://www.livestrong.com/article/110929-definition-wheat-germ/

Overview
Wheat, a member of the Gramineae, or grass, family, produces a "caryopsis" or kernel, grain or berry. Wheat germ is the embryo of the wheat kernel and is a popular source of fiber and sold in most cereal sections of most grocery stores. According to the Wheat Foods Council, wheat germ is a concentrated source of nutrients, and a rich source of fiber. Sprinkling wheat germ on your morning cereal adds 3 to 5g of additional fiber to your daily nutritional requirements as set forth by the United States Department of Agriculture.

Wheat Kernel
The wheat plant grows from the kernel, or wheat berry. These small seeds are similar to small suitcases containing three compartments--the endosperm, bran and germ--which are separated and harvested to produce flour through a milling process.According to the Wheat Foods Council, one bushel of wheat yields approximately 60 pounds of whole-wheat flour, 90 one-pound loaves of whole wheat bread, 42 pounds of white flour or 42 loaves of one-and-a-half pound loaves of white bread. Why the difference? Wheat bread retains the bran and the germ portion of the kernel, where white bread does not.

Endosperm
The endosperm is a rich source of soluble fiber, which is why it is found in many products to supplement colon health. The endosperm, consisting of protein, carbohydrates, iron, riboflavin, folic acid, niacin and thiamin, is milled to produce white flour, minus the germ portion.

Bran
Bran, which can be purchased separately, is approximately 14 to 15 percent of the kernel weight and is included in the milling process of whole wheat flour. Bran also contains smaller amounts of protein and dietary fiber than the endosperm, but has a significant amount of phytochemicals, antioxidants, B vitamins and vitamin E. In its purest, organically grown form, it is conducive to colon and heart health by constantly flushing the intestinal tract and allowing the body to absorb much needed nutrients.

Germ
The germ is the embryo, or sprouting portion of the kernel, and is approximately 2 to 3 percent of the kernel weight.

The germ is separated from the endosperm and bran in the milling process because the germ contains approximately 10 percent fat, which limits the shelf life of flour.

The germs' nutritional content consists of much smaller amounts of protein than bran, but higher concentrations of B-complex and trace minerals than the endosperm.

According to the Wheat Foods Council, wheat germ should be refrigerated after opening as it can become rancid due to the fat content.

Vitamin E in Wheat Germ
According to the Whole Grains Council, the United States Department of Agriculture incorrectly lists vitamin E as missing in crude wheat germ, though in the same database they list wheat germ oil as being high in vitamin E. That's just not possible. Wheat germ is also rich in vitamin E, as well as B-complex, and trace minerals.