Cereals have always been at the base of human food. Over time, man realized that these seeds could be harvested and at the same time, that they should be planted to ensure the supply. Thus, wild cereals became cultivated cereals, and so the man went from being a gatherer to being a farmer.
There are still villages in the world for which cereals are the only food for most of the year and there are others who consume it very often because of the supply of carbohydrates they provide. However, in developed countries their weight in food has been decreasing, especially in the last century. The main destination of cereals is human food, but also much grain is produced to feed the animals and supply the chemical industry.
Cereals are a staple in human food because of their nutritional characteristics, their moderate cost and also that they provoke a sensation of satiety, to increase its volume in the intestine, which in some societies is very important. Success in its production, storage and utilization has been central to the development of modern civilization.
Cereals are a mainly energy food. They, along with their derivatives, are a source of carbohydrates, have few fats and their grains contain very little water, hence they are retained very easily. Their nutritional qualities are due to that they contain minerals like calcium, phosphorus, iron and in smaller quantity potassium. They contain all the vitamins of group B, lack vitamin A (except corn containing carotenes), vitamin E is in the germ, but is lost with the grinding of the grain and vitamin B1, is abundant and is conserved in the bran . The seed of the cereal is formed by the shell and the grain. The first is composed mainly of cellulose fibers containing vitamin B1 and when the grain is ground and the husk is removed, the bran is obtained. For its part, the grain is formed by the germ (containing proteins of high organic value) and the nucleus, composed of starch and, in some cases as wheat or oats, by a protein complex called gluten.
Wheat, millet, rice and maize are the four most consumed cereals in the world, but others such as rye, oats and barley are also important worldwide.