Dietary bran
|
|
Dietary bran is the combined testa and fruit skin of cereal grains in the family Poaceae. Along with germ, it is an integral part of whole grains, and is often produced as a by-product of milling in the production of refined grains. Wheat and rice bran are especially common in areas where those grains are produced.
Bran is particularly rich in dietary fiber, and contains significant quantitities of starch, protein, fat, vitamins, and dietary minerals. Oat bran, alone or as a part of oatmeal, has been shown to reduce the risk of coronary heart disease when part of an overall diet that is low in saturated fat and cholesterol, and the United States Food and Drug Administration now allows manufacturers to make specific health claims to that effect on food packaging[1] (http://vm.cfsan.fda.gov/~lrd/tpoatbrn.html).
Bran is often used to enrich breads (notably muffins) and breakfast cereals, especially for the benefit of those wishing to increase their intake of dietary fiber. Bran may also be pickled, as in the tsukemono of Japan.
Bran finds particularly many uses in Japan, where it is known as nuka (糠; ぬか). Besides pickling it, Japanese people also add it to the water when boiling bamboo shoots, and use it for dish washing.
The high oil content of bran makes it subject to rancidification, one of the reasons that is often separated from the grain before storage or further processing. The bran itself can be heat-treated to increase its longevity[2] (http://www.fftc.agnet.org/library/article/pt2003037.html).
Bran oil may be also extracted for use by itself for industrial purposes (such as in the paint industry[3] (http://www.hbti.edu/oil.htm)), or as a cooking oil. Rice bran oil in particular is claimed to improve human health, as it contains oryzanol, an antioxidant claimed to help prevent heart attacks[4] (http://www.findarticles.com/p/articles/mi_m0FDN/is_5_6/ai_80490897).