The seed portion of cereals consists of numerous components which basically include three parts: a seed coat or testa (bran) storage organ or nutritive reserve for the seed (endosperm), and a miniature plant or germ.
Except for two amino acids, lysine and tryptophan, most cereals contain the essential amino acids required by humans, as well as vitamins and minerals.
When they are consumed with other foods that can supplement the nutritional elements that are low in cereals, the minimum dietary requirements may be met or nearly met.
Compositionally, cereals consist of 12-14 percent water, 65-75 percent carbohydrate, 2-6 percent lipid and 7-12 percent protein.
Oats and maize however contain relatively large amounts of lipids. Oats contain at least 10 percent lid, one third of which are polar (phosphor- and galacto-lipids).
Regardless of the grain type, wheat, corn or another grain, the endosperm is the seed component lowest in fat, containing less than the germ, with up to only 1.5% of the lipid of the seed.
Starch is the major component of cereal grains. It provides 70% to 80% of the calories consumed by humans worldwide.
On a world basis, rice is the most important cereal, being produced for human food in the largest amount, while in the United States, corn is produced in the largest amount.
The grain grown in the largest quantity for human food use in the United States is wheat.
For most food uses of cereals, the bran and the germ are removed: the bran, because it is indigestible by humans and because of its adverse effect on the appearance and on some functional properties if flour, and some germ, because of its high content, which may subsequently become rancid.
Other than soluble and insoluble dietary fiber, cereal bran contains a complex mixture of antioxidant molecules, phytoseterols, policosanols, phytoestrogens, trace minerals, vitamins and other compounds that have associated with positive cardiovascular outcomes in controlled studies.
Cereal grains component
