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Bran ( ahd. Kli (w) a ) is a collective term for the residues from the husks (seed husk, fruit husk), the aleurone layer and the seedling that remain after grain processing after sieving the flour . Bran is a mill by-product and not to be confused with the husks .

Wheat bran
Bran puke from the 18th century; Such masks were often attached to the outlet of the bran from the bag box

In the past, bran was mainly used as animal feed . In the context of wholefood nutrition , bran has become increasingly important as a source of fiber for human nutrition (for example in muesli , graham bread or in crispbread ). Bran consists mainly of the non-starch carbohydrates cellulose and hemicellulose, as well as lignin .

Milling extraction

Since bran essentially consists of the outer layers of the grain, the grain must be thoroughly cleaned of adhering dirt, microorganisms and any other contaminants before grinding. This is done in the flour mill by means of black and white cleaning .

Bran is the residue of outer layers and seedlings that remains after grinding and sieving the flour ( plansifter ). As a mill byproduct , bran should contain a maximum of 20% starch. The composition of the bran depends on the milling technology used. In the case of wholemeal flours or meal, the bran is also ground.


Average composition

The bran of selected types of grain has the following composition:

Ingredient (%) wheat rye oats rice barley
Non-starch carbohydrates 45-50 50-70 16-34 18-23 70-80
Strength 13-18 12-15 18-45 18-30 8-11
protein 15-18 8-9 13-20 15-18 11-15
fat 4-5 4-5 6-11 18-23 1-2

Average composition of wheat bran

The composition of wheat bran naturally fluctuates, both depending on the environmental conditions (soil, climate) and the cultivation technique (fertilization, plant protection).

Details per 100 g of edible portion:

water 11.5 g
protein 14.9 g *
fat 4.7 g
carbohydrates 17.3 g **
Fiber 45.4 g
Minerals 6.2 g
sodium 2 mg
potassium 1350 mg
magnesium 490 mg
Calcium 65 mg
manganese 13 mg
iron 16 mg
copper 1300 µg
zinc 9400 µg
phosphorus 1140 mg
iodide 30 µg
selenium 2 µg
Retinol (Vit. A 1 ) 1 µg
Thiamine (Vit. B 1 ) 650 µg
Riboflavin (Vit. B 2 ) 510 µg
Nicotinic acid (Vit. B 3 ) 18 mg
Pantothenic acid (Vit. B 5 ) 2500 µg
Vitamin B6 730 µg
Folic acid 195 µg
Vitamin E. 2700 µg
amino acids
Arginine 1 1230 mg
Histidine 1 440 mg
Isoleucine 770 mg
Leucine 1120 mg
Lysine 720 mg
Methionine 250 mg
Phenylalanine 650 mg
Threonine 590 mg
Tryptophan 250 mg
Tyrosine 460 mg
Valine 880 mg

* Protein content according to the EU directive on nutrition labeling; (Factor: 6.25): 16.0 g
** Difference calculation
1 mg = 1000 µg

The physiological calorific value of wheat bran is approx. 720  kJ / 100 g (172  kcal / 100 g), for oat bran it is approx. 1,312 kJ / 100 g (309 kcal / 100 g).

Health importance

The swellable and mucus-forming components of bran (β- D - glucan and water-soluble xylans ) ensure that the increase in blood sugar after starch intake is delayed, which is desirable for people with diabetes . In addition to vitamins and minerals, the outer layers of the grain also contain undesirable ingredients such as antibodies against predators (such as phytin ) and impurities (such as pesticides , heavy metals and mold toxins ). Phytin binds minerals and vitamins in the intestine and thus prevents these substances from being used for nutrition.

When using bran for human nutrition, care must be taken to ensure adequate hydration, otherwise serious constipation can result. In the worst case, it can lead to a life-threatening intestinal obstruction .

Bran was and is valued as a feed component especially for horses because of its high fat, protein and magnesium content. However, the protein cannot be used well. Bran also contains a lot of phosphorus, so that the phosphorus / calcium ratio is unfavorable. This used to lead to miller's horse disease and can be avoided by adding lime. Bran is included in some mash recipes and is used as additional feeding when it is soaked (max. 10%).

See also


  • Wilfried Seibel (Hrsg.): Goods knowledge of grain . AgriMedia, Bergen / Dumme 2005, ISBN 3-86037-257-2 .
  • Peter Erling (Hrsg.): Manual flour and peeling mill . AgriMedia, Bergen / Dumme 2004, ISBN 3-86037-230-0 .

Individual evidence

  1. a b Waldemar Ternes , Alfred Täufel, Lieselotte Tunger, Martin Zobel (eds.): Food lexicon . 4th, comprehensively revised edition. Behr, Hamburg 2005, ISBN 3-89947-165-2 .
  2. German Research Institute for Food Chemistry (DFA), Garching (Hrsg.): Food table for practice . The little souci · specialist · herb. 4th edition. Wissenschaftliche Verlagsgesellschaft, Stuttgart 2009, ISBN 978-3-8047-2541-6 , p. 244 .
  3. Helmut Sigel: Zinc and Its Role in Biology and Nutrition. Dekker, New York 1983, ISBN 0-8247-7462-0 ( Metal Ions in Biological Systems. Volume 15), p. 333.
  4. , accessed on Jan. 13, 2018.
  5. , accessed on January 13, 2018.
  6. , accessed on Jan. 13, 2018.