Cereal germ

Cereal germ is the embryo of a cereal grain, the part that would grow into a new plant, and it is commonly separated out along with the bran during milling to produce refined grain products. As a byproduct of that process it is a concentrated source of nutrients such as vitamin E, folate and magnesium, and its oil, including wheat germ oil and rice bran oil, is extracted for use as a cooking oil or added directly to foods. Its high polyunsaturated fat content also makes it prone to oxidation, which is why removing it extends the shelf life of refined flour; whole-grain foods keep the germ intact and so retain its nutritional benefits.