Cereals

There is a wide variety of grains: rice, millet, oats and others less familiar. They have been, and still are, staple food for some civilizations and cultures.
The ancient Chinese depended upon millet, buckwheat, and rice as their staples; the Aztecs and Mayans subsisted mainly on corn; the Egyptians grew some of the world's finest wheat.

Our way of eating have changed with time, leaving the cereals on the side. Even if some countries have kept their ancestral recipes, it is now seldom to find recipes with barley, quinoa or other cereals in our cookbooks.

Composition
They are composed of complex carbohydrates (between 60 and 80 % of the calories in grains come from carbohydrate). They provide proteins, B vitamins (thiamine, riboflavin, and niacin), vitamin E for some of them and minerals (iron, zinc, calcium, selenium and magnesium).
If they are non processed, they also are an excellent source of fiber.

However the protein is incomplete. Cereals are deficient in lysine, an essential amino acid. But it is possible to complete this deficiency by eating foods that contain this amino acid such as legumes.

Description
Cereal groups contain true grains such as wheat, rice, oats, rye, millet, corn which are members of the grass family Graminea and non-true grains such as amaranth, quinoa, and buckwheat which belong to different botanical families.
Because the kernels of all of these have a similar composition they all belong to the cereal family.

The grain itself is composed of different parts:

The heart of the grain is the germ, or embryo. This is the part which, if the seed is planted, will develop into a new plant. It is in the germ that most of the vitamins and minerals are stored. It contains high concentration of vitamin E and B vitamins, iron and other minerals, polyunsaturated fats, proteins, fiber and carbohydrates.
The endosperm contains most of the starch in the grain. This is the major part of the grain; it accounts for about 80 % of the grain's weight. Most of the protein and carbohydrate are stored in the endosperm as are some minerals and B vitamins. It also contains some dietary fiber.
The aleurone surrounds and protects the endosperm.
Several layers of bran and the husk contain carbohydrates, proteins, vitamins and minerals, (especially iron), and fiber.

Processing
Grains are seeds which can be used in many different ways: whole, sprouted, cooked, milled, cracked, rolled into flakes...

Flakes
There are different methods to process grains into flakes. Generally the grains are heated and pressed flat with steel rollers.
Flour
Flour is a soft dry powder that is usually ground from grain (it can be made from vegetables, fruits, legumes and even fish).
Milling techniques have changed drastically since the first wheat kernels were ground into flour. The earliest mills ground the germ right along with the endosperm, releasing the wheat germ oil into the flour. But the wheat germ oil soon becomes rancid and spoiled the flour.
Now most flour is milled by roller process in which seeds are alternately put through a series of high-speed steel rollers and mesh sifters. Since roller milling separates the bran and the germ from the endosperm, the germ is not ground and so does not release the oil.
White and refined flour consist almost entirely of the ground endosperm and whole flour retain the three constituents (endosperm, bran and germ) which are recombined after milling. White flour is devoted lot a of nutrients available in the whole grain. During the processing, 80 % of the vitamins and minerals and 75 % of the fibers are lost. What is left in white flour is ground up endosperm. The removal of nutrients and almost all fibers from grain creates an unbalanced product. The body needs nutrients especially the fibers which help the peristaltic action of the colon.
White flour and its products are constipating the bowels. This induces a stagnation of wastes in the digestive tract and leads to development of unhealthy microorganisms that cause discomfort and sometimes diseases.
The more a grain is processed, the more it has lost its nutrients

**Composition of différent wheat products (for 100 grammes)**
	Calories	Proteins	Fats	Carbohydrates	Fibre	Calcium	Zinc	Phosphorus	Iron	Sodium	Potassium	Thiamine	Riboflavin	Niacin
Wheat berry	332 g	10.5 g	1.5 g	69 g	1.9 g	40 mg	5.50 mg	300 mg	4 mg	12 mg	450 mg	0.40 mg	0.2 mg	4 à 8 mg
Whole wheat flour	340 g	10.5 g	1.5 g	71 g	2 g	40 mg	5.50 mg	300 mg	4 mg	10 mg	450 mg	0.35 mg	0.2 mg	4 à 8 mg
White flour	353 g	9.5 g	1.2 g	75 g	0 g	16 mg	1.7 mg	120 mg	1.2 mg	3 mg	135 mg	0.1 mg	0.08 mg	0.6 mg
Wheat germ	390 g	25.2 g	10 g	49.5 g	1 g	90 mg	2 mg	1100 mg	8 mg	0 mg	780 mg	1 à 1.50 mg	1 à 4 mg	5 mg

Ref: Tables de composition des aliments, Lucie RANDOIN