Bran

wheat bran
'Bran' is the hard outer layer of
grain and consists of combined
aleurone and
pericarp. 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. When bran is removed from grains, they lose a portion of their nutritional value. Bran is present in and may be milled from any cereal grain, including
rice,
wheat,
maize,
oats, and
millet.
Bran is particularly rich in
dietary fiber, and contains significant quantitities of
starch,
protein,
fat,
vitamins, and
dietary minerals.
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 used for
pickling, as in the
tsukemono of
Japan.
Rice bran finds particularly many uses in Japan, where it is known as ''nuka'' (糠; ぬか). Besides using it for pickling, Japanese people also add it to the
water when
boiling bamboo shoots, and use it for
dish washing. In
Kitakyushu City, it is called ''Jinda'' and used for stewing fish, such as
sardine.
Rice bran is a by-product of the rice milling process, and it contains various antioxidants that impart beneficial effects on human health. It is well known that a major rice bran fraction contains 12%-13% oil and highly unsaponifiable components (4.3%). This fraction contains tocotrienol, gamma-oryzanol, and beta-sitosterol; all these constituents may contribute to the lowering of the plasma levels of the various parameters of the lipid profile. Rice bran also contains a high level of dietary fibers (beta-glucan, pectin, and gum). In addition, it also contains 4-hydroxy-3-methoxycinnamic acid (ferulic acid), which may also be a component of the structure of non-lignified cell walls.
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.
'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.
In
Romania, the fermented
wheat bran is usually used when preparing sour
soups, called
borshch.
Health effects
Eating foods rich in bran became somewhat of a health craze in the late
1970s and early
1980s, with massive promotion of bran cereals and
granola. In the late
1980s, there was the "
oat bran craze," with oat products in all shapes and sizes flooding the market (including
potato chips with oat bran added), claiming to lower blood
cholesterol and fight
heart disease. This craze peaked in
1989 and was short-lived, as studies in the early
1990s showed that oat bran only modestly reduced cholesterol. However, in January
1997, the
Food and Drug Administration decided (with some controversy) that food with a lot of oat bran or rolled oats can carry a label claiming it may reduce the risk of heart disease, when combined with a low-fat diet. As of
2005, this disposition still appears on many
oatmeal packages.
★ Wheat bran (''miller's bran'') is very effective in treating
constipation. Wheat bran is known to absorb large amounts of water and expand, which has led some to claim that bran helps lead to satiety by filling up the stomach with added volume.
Colorectal cancer might be prevented by dietary wheat bran. Indeed, many epidemiological studies pointed out a protective effect of fiber intake, and more than 15 preclinical studies show that wheat bran can reduce carcinogenesis in rats and mice. Thus, several randomized clinical trials were conducted in hundreds of volunteers to test the hypothesis that wheat bran supplements would reduce adenomatous polyp recurrence. Clinical and preclinical data are available on the
Chemoprevention Database. Sadly, the main conclusion of these trials is that wheat bran does not prevent colorectal polyp recurrence: bran may thus not be an effective colon cancer preventing agent. There is strong evidence that rice bran may have a cancer preventive potential
[1][2] [3].
★
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]
★ Rice bran fraction derived from Driselase treatment prevents high blood pressure,
hyperlipidemia, and
hyperglycemia.
[2] Driselase is a commercial plant cell wall-degrading enzyme mixture containing
cellulase,
xylanase, and
laminarinase; however, it is
esterase-free.
Bran for pets and companion 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. Wheat bran is also sometimes fed to horses for its laxative qualities and nutritional value.
See also
★
Alkylresorcinols
★
Chaff
★
Husk
★
IP6
★
Phytic acid
Outside Links
★
Add Some Rice To Your Life--Advances in Rice-Based Products with Potential Benefits to Health (scientific paper), by Raxit J. Jariwalla, Ph.D.
References
1. FDA PROPOSES HEALTH CLAIMS FOR OATMEAL AND OAT BRAN 1996
2. How Nice, Brown Rice: Study Shows Rice Bran Lowers Blood Pressure In Rats, Science Daily, March 3, 2006