Bran layer, whole grains

The grain is surrounded by a live-layer coat called bran that makes up 15% of the mass of the whole grain. It is rich in B vitamins and contains about 50% of the total mass of minerals of the grain. The bran consists of cellulose and is indigestible for humans. It is separated during flour production and used as animal fodder. 

When oats are processed, the hull is removed, leaving the whole grain. After further processing, the whole grain oat will become rolled, steelcut, or instant oats. The outer covering of the whole grain oat is bran. In the production of oat bran, however, the bran plus 3 to 4 layers of cells called aleurone layers are included in the final product. 

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