Each raw oat grain is made up of two parts: the inedible outer hull (the husk) and the oat kernel (groat). Within the groat are to be found the oat germ, the starch cell and the outer layer. oat bran is derived from the outer layer of the oat groat (hulled oat kernel). See figure in inset. It takes approximately 5 Kg. of raw oats to produce 1 Kg. o...