Bran

For other uses, see Bran (disambiguation).
Not to be confused with Chaff.

Wheat bran structure (E: outer layer; I: intermediate layer; A: aleurone layer)

Bran, also known as miller's bran, is the component of a cereal grain consisting of the hard layers - the combined aleurone and pericarp - surrounding the endosperm. Corn (maize) bran also includes the pedicel (tip cap).[1] Along with the germ, it is an integral part of whole grains, and is often produced as a byproduct of milling in the production of refined grains. Bran is highly nutritious, but is difficult to digest due to its high fiber content; its high fat content also reduces its shelf life as the oils/fats are prone to becoming rancid. As such, it is typically removed from whole grain during the refining process - e.g. in processing wheat grain into white flour, or refining brown rice into white rice.

Bran is present in cereal grain, including rice, corn (maize), wheat, oats, barley, rye, and millet. Bran is not the same as chaff, which is a coarser, scaly material surrounding the grain, but does not form part of the grain itself, and which is indigestible by humans.[2]

  1. ^ Corn Chemistry and Technology Watson and Ramstad 1987 p. 69
  2. ^ Catsberg, C. M. E. (1990). Food Handbook. Dordrecht: Springer Netherlands. doi:10.1007/978-94-009-0445-3_15. ISBN 978-94-009-0445-3. "chaff, which is indigestible for humans"