High Quality Content by WIKIPEDIA articles! The germ of a cereal is the reproductive part that germinates to grow into a plant; it is the embryo of the seed. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ, rice bran, and maize may be used as a source from which vegetable oil is extracted, or used directly as a food ingredient. The germ is retained as an integral part of whole grain foods.