There are four main parts of a rice grain. A grain of rice is a seed that contains an embryonic rice plant, stored food and a protective coat.
The HUSK (hull) is the outer straw-like protective covering that surrounds the entire grain. It is inedible and must be removed before the grain can be seen. Under the husk is the BRAN (germ).
The germ is the plant EMBRYO from which a plant emerges. The bran layers include layers of fibrous tissue with protein, vitamins, minerals and oil.
ENDOSPERM is found beneath the bran layers. The white endosperm is made of complex carbohydrates (starch), the energy source used by the germinating rice plant. The endosperm is also the largest portion of the rice grain.
The bran, germ and endosperm are the edible portions of the grain. In the milling process, the inedible husk is removed to make brown rice. If the rice is further milled to remove the bran and germ, the result is white rice.