A grain of wheat is a seed which can grow into a new wheat plant, and is also the part of the wheat plant which is processed into flour. Wheat grains are generally oval shaped, although different wheats have grains that range from almost spherical to long, narrow and flattened shapes. The grain is usually between 5 and 9mm in length, weighs between 35 and 50mg and has a crease down one side where it was originally connected to the wheat flower.
The grains are commonly a red colour, although many wheats have white grains and more unusually purple, black, brown or green/grey varieties exisit. The wheat grain (or kernal) is divided into several parts, as shown in the diagram.
|The three main parts are:|
The outer coating or "shell" of the wheat kernel is made up of several layers. These layers protect the main part of the kernel. Bran is rich in B vitamins and minerals.
This is the main part of the wheat kernel and represents about 80% of the kernel weight. It is from this part that white flour is milled. The endosperm is rich in energy-yielding carbohydrate and important protein.
|Germ or Embryo||
This part grows into a new plant if sown. The germ lies at one end of the grain and represents only 2% of the kernel. It is a rich source of B vitamins, oil, vitamin E and natural plant fat. It needs to be removed during milling because the fat is liable to become rancid during flour storage. Wheat germ is still very valuable though and is used in many products.