Cereal grain is composed of three main parts: starchy endosperm, bran and germ. Grain milling aims to separate these three parts, resulting in pure endosperm flour and different side stream products like bran. Cereal bran comprises 3-30 % of the dry weight of cereal grain, depending on the type of cereal. Figure 1 presents bran fractions of oat, maize and wheat.
Figure 2 shows the anatomical parts of the wheat grain. Bran forms a protective layer around the grain, and the bran is further composed of multiple layers including pericarp, testa, hyaline and aleurone layer.
Cereal bran is a good source of dietary fiber, protein, minerals, E and B-vitamins and different phenolic compounds. Table 1 shows the amounts of some of the nutritional components of wheat, oat and maize bran.
References
- [THL] Nutrition Unit of the National Institute for Health and Welfare: Fineli, National Food Composition Database in Finland. [Date cited: 15.9.2021]. Available: https://fineli.fi/fineli/en/index
- [USDA] U.S. Department of Agriculture: FoodData Central. [Date cited: 17.9.2021]. Available: https://fdc.nal.usda.gov/
- Surget A, Barron C. Histologie du grain de blé. Industrie des Céréales 2005, 145: 3–7. In: Hemery Y, Xavier R, Lullien-Pellerin V, Barron C, Abecassis J. Dry process to Develop wheat fractions and products with enhanced nutritional quality. Journal of Cereal Science 2007, 46: 327–347.