Cereals (grains) are the seeds and energy stores of cultivated grasses.
The main types are:
Wheat
Rice
Maize (Corn)
Millet
Sorghum
Barley
Oats
Rye
Spelt
In some countries, ‘cereal’ is also a term for dry foods made from grains and other ingredients, often eaten with milk for breakfast.
Cereals contain variable amounts of protein, oils, B vitamins, vitamin E and tocotrienols, iron, and various trace elements, as well as phytochemicals, some of which, such as the antioxidants, are bioactive. The germ is the embryonic part of cereal plants and contains oils, proteins, and fibre. Various cereals contain other specific components. Wheat contains gluten (a mixture of proteins). Rye has high levels of pentosans and oats contain beta-glucans, both of which are non-starch polysaccharides, a characterising feature of dietary fibre.
Wholegrain and Refined Cereals and Their Products
[extract from Second Expert Reports on Cancers and Nutrition by WCRF 2009 - http://www.dietandcancerreport.org/]
Many of the cereals (grains) that we consume are refined. Grains are first broken into pieces and then refined, sifting away the bran, germ and, usually, the aleurone layer. This removes most of the fibre, oil, and B vitamins, as well as approximately 25 per cent of the protein. Polishing, as often performed on rice, removes additional nutrients. Many high-income countries therefore fortify refined cereals, including flour, with B vitamins and iron. Wholegrain products generally contain the constituents of the grain but, given the absence of an internationally accepted definition, intact grains are present to a variable extent. The extent to which the grain remains intact influences physiological processes in the bowel and hence health.
Cereal foods may be eaten in wholegrain form, although consumption in refined forms, such as white rice, bread, or pasta, is generally much more common, particularly in high-income countries. Refined grains are considered easier than wholegrains to cook and to chew; are light in colour — which is attractive to many consumers; and also have a longer shelf-life than wholegrain products, as the oil in bran goes rancid relatively quickly.
Breakfast cereals, particularly in the United States and parts of Europe, also account for a significant proportion of grain eaten. Many breakfast cereals, although based on grains (whole or refined), may contain substantial amounts of added sugars. Grains are further processed to provide ingredients such as corn syrup, starch, or alcohol. They also form the basis of many animal feeds.
Processed grains have a higher glycaemic index than unprocessed grains and, generally, the greater the degree of processing, the greater the glycaemic index.
Processed
Wheat
Milled for flour for bread, pastries, cakes, and pasta.
Corn
Latin America, parts of Asia and Africa
Used to make grits, cornmeal (for polenta as well as cornbread), corn flour, tortillas, tamales, and corn chips.
Basis of corn starch (a thickener)
Basis of corn syrup (a sweetener)
Basis of corn oils
Sweetcorn is also a vegetable eaten on or off the cob.
Rice
Processed to remove the bran and aleurone layers - turns 'brown rice' into 'white rice'.
Turned into Rice Flour - for gluten-free breads
Also Rice Powder, Noodles, Rice Paper, Rice Milk
Japan - mochi - sticky rice blocks
China - lao chao - (Chinese fermented rice)
Barley
Used mainly in Asia
Tibet - tsampa - barley flour mixed with water
Japan/Korea - miso paste / barley tea
North Africa - soups, porridges and flat breads.
Rye
Whole Rye grains are milled and used to make bread in North and East European countries
Oats
Oats are made into porridges, muesli and baked goods.
Oat Milk, Oat Cream (good instead of cow's milk in pasta sauces)
Other Grains Etc (more common in parts of Africa and Asia
Fonio
Millet
Sorghum
Teff
Triticale
Amaranth - not exactly a grain
Quinoa - not really a grain
Many grains are also fermented to make alcoholic drinks.