Bran is the hard outer layer of grain (the grass fruit) and consists of combined aleurone and pericarp. Bran should not be confused with chaff, which is coarser scaly material surrounding the grain, but not forming part of the grain itself.
Significance of Bran for the Seed:
- The aleurone layer surrounds the endosperm tissue (endosperm is the part of the seed which surrounds the embryo and provides nutrition in the form of starch) and functions for both storage and digestion.
- During germination, aleurone secretes the amylase enzyme that breaks down endosperm starch into sugars to nourish the growing seedling.
- In cereals with starchy endosperm, the aleurone contains about 30% of the kernel's proteins.
- In multicolored corn, anthocyanin pigments in the aleurone layer give the kernels a dark, bluish-black color
- Pericarp is the tissue that develops from the ovary wall of the flower and surrounds the seeds. It provides protection to seed.
Significance of Bran for the humans:
- Bran is particularly rich in dietary fiber. It 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.
- Eating bran is one of the quickest and best ways to increase fiber in the diet. It is indigestible and it increases the weight and size of the stool more than the fiber contained in fruits or vegetables. It does not irritate the lining of the stomach, small intestine or colon. It is not a laxative but promotes the movement of fecal matter through the colon in a natural way. Unlike drugstore laxatives or other natural strong laxatives, bran does not quickly purge out all the contents in your colon.
- Bran is rich in omegas. Omegas are essential fatty acids that cannot be constructed within humans from other components by any known chemical pathways, and therefore must be obtained from the diet.
- Bran contains 12% - 13% oil and studies have shown that rice bran oil is rich in gamma-oryzanol. This includes its ability to reduce plasma cholesterol, reduce cholesterol absorption and decrease early atherosclerosis, inhibit platelet aggregation, and increase fecal bile acid excretion. Oryzanol has also been used to treat nerve imbalance and disorders of menopause.
- Bran contains significant quantities of starch, protein, vitamins, and dietary minerals.
- Rice bran contains various antioxidants that impart beneficial effects on human health.
- Bran oil may be also extracted for use by itself for industrial purposes (such as in the paint industry), or as a cooking oil, such as rice bran oil.
- Studies have shown that some of the nutrients and phytochemicals present in wheat bran, may also protect against cancer. These include phytic acid and various phenolic components such as phenolic acids, lignans and flavonoids.
- Rice bran oil's smoke point is 490 degrees F, higher than even grapeseed oil (480 degrees) or peanut oil (320 - 450 degrees). This means that even in the hottest of situations, rice bran oil won't smoke or breakdown. When cooking or grilling, you do not want your oil to smoke, because it imparts a negative flavor to the foods so when you use rice bran oil foods will taste better, and they will be less likely to stick to the grill or griddle when.
- Some research suggests that there are particularly high levels of inorganic arsenic (a toxin and carcinogen) present in rice bran, and that any health benefits may not be worth the potential detriments. Other types of bran (derived from wheat, oat or barley) contain less arsenic than rice bran.
- Due to the high oil content of bran, it tends to get rancid (decomposition of fats, oils and other lipids by hydrolysis or oxidation). To avoid rancidification it is best to store in refrigerator or in a vacuum-sealed container at a moderate temperature. Rancidification makes the bran bitter.
Significance of Bran for animals:
- Bran is widely used as a major component in pet foods for rabbits and guinea pigs.
- Rice bran is sometimes fed to horses for its nutritional value, particularly as a plant-based fat supplement. It is considered an excellent way to put weight onto a thin horse, without the problems associated with overfeeding grain.