Wheat and other cereals are at their most nutritious in whole-grain
form when they contain greater levels of most B vitamins and fiber.
Most of the wheat grain's fiber, oil and B vitamins, as well as iron,
vitamin E and a quarter of its protein, come from the germ at its base
and the layer of starchy tissue which surrounds its core - the
endosperm.
For most cereals, milling involves the removal of the outer husk, or
bran, and the nutrient-rich germ from the endosperm which is then used
to make flour. The separation process increases the storage life of
flours because the oils of the germ are susceptible to oxidation and
can become rancid within a few weeks. Although cereal bran adds bulk to
the diet, an excess can irritate the bowel. Milling often involves
complex sifting operations to produce highly refined flours from which
almost every trace of bran has been removed. The presence of bran adds
substance and texture to refined products.
Many people prefer the softer texture of refined cereal products such
as white bread and polished white rice. Most manufacturers now
compensate for nutritional losses that result from milling by
fortifying foods such as breakfast cereals, with B vitamins and iron.
Though they may be fortified with vitamins, refined products contain
less fiber than wholegrain foods. Fiber helps to prevent constipation
and may help to reduce the risk of developing bowel disorders including
hemorrhoids and bowel cancer.
The most common cereals
Barley - is a staple food in the Middle East, but in the West it is
used mainly in the form of malt by brewers and distillers, and as
animal feed. Pearl barley, which is added to soups and stews, is highly
refined, offering plenty of carbohydrate but little in terms of
vitamins and fiber.
Maize - or corn is gluten-free and is the basis of an extraordinarily
wide range of foods, including popcorn, cornflour, cornmeal, breakfast
cereals, bourbon, and other American whiskeys and corn syrup - a
sweetener used in many manufactured desserts.
Millet - is also gluten-free and therefore a useful cereal for people
with gluten intolerance. For the same reason, it cannot be used for
raised breads but is made into flat breads in Asia and north Africa
where millet is a staple food.
Oats - do not contain gluten and are therefore suitable for people with
coeliac disease. Because milling removes most of the husk but leaves
the germ intact, oatmeal is relatively high in protein and oil. This
means that, unless it is steamed before packaging, it also turns rancid
more quickly than most other cereals. The soluble fiber in oats has
been found to be particularly helpful in lowering blood cholesterol
levels.
Rice - is the staple food for around half the world's population.
Nutritionally, brown rice is a good source of B vitamins. It also
contains calcium and phosphorous.
Rye - contains enough gluten to make a weak dough, but the bread
produced, such as rye bread and pumpernickel, is heavy and moist. A
type of American whiskey is distilled from rye, and the grain is also
used in crisp breads.
Wheat - is classified as hard or soft according to the gluten content
of the many different varieties. The hardest, and the highest in
gluten, is durum which is used to make pasta. The softer, lower-gluten
flours are preferred for biscuits, cakes and pastry.
Semolina consists of coarse particles of wheat endosperm. Finely ground
semolina is mixed with water and flour to make pellets which are served
steamed in the north African dish couscous.
Wholewheat flour, which includes the bran and the germ, is a useful
source of dietary fiber and B complex vitamins.
