Peanut is from the botanical family Fabaceae. Cultivated peanut, Arachis hypogaea, is actually a hybrid from wild species of peanuts, created probably in northwestern Argentina, thousands years ago. From there it spread to Peru, Ecuador, Brazil, Paraguay, and Uruguay.
Although peanut flowers are above ground, fruits are below ground (so peanuts do not grow on trees like walnuts, neither as a part of root, like potatoes). It usually takes four or five months for plant to grow and give products. It is oval leafed plant about 18 inches tall. It needs warm climates, so it grows in Asia, Africa, Australia, and North and South America. Until 20th century peanuts were mostly used as animal food.
There are many varieties of peanut, but four of them are main:
Runner Peanuts - it was introduced in 1970's and became popular because of good flavor, that it immediately increased peanut yields. Half of annual production goes to peanut butter. It has uniform kernel size. Mainly is produced in Georgia, Alabama, Florida, Texas, and Oklahoma.
Virginia Peanuts - it is peanut with have the largest kernels. Usually, we buy this type in-the-shell. Mostly is produced in Virginia and North Carolina.
Spanish Peanuts - this type has smaller kernels with a reddish-brown skin on its. They are known for a higher oil content than other varieties. Mostly are produced in South Africa, Oklahoma, and Texas.
Valencia Peanuts - it has three or more small kernels to a pod and a bright-red skin. It is type for fresh use (also popular as type for boiled peanuts), but it is also on the market as roasted and in-the-shell. It grows mostly in New Mexico.
Peanuts contain essential nutrients, B vitamins, vitamin E, dietary minerals (especially manganese, magnesium, and phosphorus) and dietary fiber. At the same time, its are cholesterol-free and rich in proteins (one ounce of peanuts gives us 15% of the Reference Daily Intake).
One ounce of peanuts has almost half of the 13 vitamins and more than one third of the 20 minerals needed for our overall health. Maybe it looks small but has more antioxidants than apples or carrots.
Peanut is ideal in a weight loss diet, even it reduces the risk of obesity.
By Harvard’s Nurses’ Study from 1998, eating peanuts five time a week can prevent heart disease. It is unclear, but probably due to minerals from peanuts: copper, phosphorous, magnesium, iron, potassium, selenium, zinc and calcium, peanuts have a protective effect for our heart. Thanks to unsaturated fat (also called "good fat"), peanuts can help lower cholesterol in our blood when we use it instead of saturated animal fat in the diet.
Resveratrol, antioxidant from peanut, also found in red grapes and red wine and thanks to him there's French paradox (the fact that in France people consume a diet that is not low in fat, but in the same time they have a lower risk of cardiovascular disease compared to the U.S.), also has protective function against cancers, heart disease, degenerative nerve disease and Alzheimer's disease. Also, it may reduce stroke risk and viral infections. Animal study from the Journal of Agricultural and Food Chemistry showed that resveratrol improves blood flow in the brain to 30%, which can reduce the risk of stroke. The fact is that peanut contains much less resveratrol than red wine and the amounts used in these studies are higher, but frequently consumption may cause same effects. Taiwanese study, which has lasted 10 years, showed that consumption of peanuts 2 or more times a week was associated with a 58% lowered risk of colon cancer in women and a 27% lowered risk in men.
Peanuts are also beneficial for maintaining healthy hair, even helpful for treating male pattern baldness because omega 3 fatty acids strengthen scalp health and stimulate hair growth.
In the United States, there's low that any product with name "peanut butter" must has at least 90% peanuts (rest 10% may be salt, sweetener, and an emulsifier). Products with different percentage are labeled as peanut spread. The ancient South American Indians first made and ate peanut butter, although according to some historians say that it was invented by a physician in St. Louis about 1890.
Historical reference has it, however, that peanut butter was invented by a physician in St. Louis about 1890 as a health food for the elderly. No one remembers the physician's name, although records show that in 1903 Ambrose W. Straub of St. Louis patented a machine to make peanut butter.
Marcellus Gilmore Edson (1849 – 1940) of Montreal, Quebec (in Canada) was the first to patent peanut butter in 1884.
When it's eaten like a snack, there's plain roasted peanuts or roasted-in-the-shell (with or without salt); both can be roasted in oil or by a dry-roasting process.
Peanuts are also used in candy industry - there's chocolate-covered peanuts and peanut brittle.
Oil of peanuts is tasteless, doesn't absorb nor transfer flavors, and can be used to high temperatures (450 degrees F) before it smokes. In use is also peanut flour, usually as a gluten-free solution. There are also, specially processed, defatted peanuts.
Peanut is popular across Latin America, so in Peru there's traditional dish called picante de cuy in which is used sauce of peanuts. In the Middle East, in Israel, kabukim, crunchy coated peanuts, is popular. In Asia, in Philippines, the most popular dish with peanuts is kare-kare. In Africa is mostly used peanut butter, as well as in America, but they also use peanut powder.
Peanut, or even use of products based on peanuts, can cause allergy, so some schools in the USA have banned peanuts. The reaction can start within minutes of touching or eating a peanut, so be careful. Peanut allergies have doubled in the last decade. Also, it's recommended to roast peanuts, because of aflatoxin, which is a dangerous carcinogen and can cause serious liver problems.
In 1900's, Dr. George Washington Carver, a scientist at Tuskegee Institute in Alabama, discovered 300 uses for peanut plant.
From shells, skins and even kernels, it can be made a variety of non-food products. Skin of peanuts is ideal for paper making, and shells are used for plastic and abrasives. Believe it or not, but peanuts are actually used (as an ingredient) in other products like detergent, metal polish, bleach, ink, shaving cream, face creams, soap and other cosmetics, but also in linoleum, rubber, paint, explosives, and medicine.
India and China make it more than half of the world's production of peanuts. The largest production belongs to China, India, Nigeria and the United States of America.