, or groundnut
), is a species in the legume family
) native to South America, Mexico
and Central America. It is an annual
plant growing tall. The
are opposite, pinnate
with four leaflets (two opposite pairs; no
terminal leaflet), each leaflet 1 to 7 cm (⅜ to 2¾ in) long
and 1 to 3 cm (⅜ to 1 inch) broad. The flowers
are a typical peaflower in shape, 2 to
4 cm (¾ to 1½ in) across, yellow with reddish veining. After
, the fruit
develops into a legume long, containing 1 to 4
, which forces its way underground to
Peanuts are known by many local names, including
, ground nuts
, monkey nuts
nuts is often
used to mean the entire pod.
The domesticated peanut is an amphidiploid
, meaning that it has two sets
of chromosomes from two different species. The wild ancestors of
the peanut were thought to be A.
, a view recently confirmed by direct comparison
of the peanut's chromosomes with those of several putative
ancestors. This domestication might have taken place in Argentina
or Bolivia, where the wildest strains grow today. In fact, many
cultures, such as the
, depicted peanuts in their art.
demonstrates that peanuts were domesticated in prehistoric times in Peru.
Archeologists have (thus far) dated the oldest specimens to about
7,600 years before the present. Cultivation spread as far as
Mesoamerica where the Spanish conquistadors found the
whence Mexican Spanish
and French, cacahuète) being offered for sale in
the marketplace of Tenochtitlan
City). The plant was later spread worldwide by European
The legume gained Western popularity when it came to the United
States from Africa. It had become popular in Africa after being
brought there from Brazil by the
Peanut shells, with one split open
revealing two seeds with their brown seed coats
The orange veined, yellow petaled, pea-like flower of the
is borne in auxiliary clusters above
ground. Following self-pollination
the flowers fade and wither. The stalk at the base of the ovary,
called the pedicel, elongates rapidly, and turns downward to bury
the fruits several inches in the ground, where they complete their
development. When the seed is mature, the seed coat (mesocarp)
changes color from white to a reddish brown. The entire plant,
including most of the roots, is removed from the soil during
The pods act in nutrient absorption. The fruits have wrinkled
shells that are constricted between pairs of the one to four
(usually two) seeds per pod. The mature seeds resemble other legume
seeds such as beans, but they have paper-thin seed coats, rather
than the usual, hard legume seed coats.
Peanuts grow best in light, sandy loam
They require five months of warm weather, and an annual rainfall of
or the equivalent in irrigation
The pods ripen 120 to 150 days after the seeds are planted. If the
crop is harvested too early, the pods will be unripe. If they are
harvested late, the pods will snap off at the stalk, and will
remain in the soil.
Peanuts are particularly susceptible to contamination during growth
and storage. Poor storage of peanuts can lead to an infection by
the mold fungus
releasing the toxic
. The aflatoxin-producing molds exist
throughout the peanut growing areas and may produce aflatoxin in
peanuts when conditions are favorable to fungal growth.
Harvesting occurs in two stages. First a machine is used to cut off
the main root of the peanut plant by cutting through the soil just
below the level of the peanut pods. The machine lifts the "bush"
from the ground and shakes it, then inverts the bush, leaving the
plant upside down on the ground to keep the peanuts out of the
dirt. This allows the peanuts to dry slowly to a bit less than a
third of their original moisture level over a period of 3–4
After the peanuts have dried sufficiently, they are thresh
, removing the peanut pods from the rest of
the bush. How peanuts are Grown - Harvesting - PCA
Cultivation in China and India
The peanut was introduced to China
by Portuguese traders in the
1600s and another variety by American missionaries in the 1800s.
They became popular and are featured in many Chinese dishes, often
being boiled. During the 1980s peanut production began to increase
greatly so that as of 2006 China was the world's largest peanut
producer. A major factor in this increase has been China's move
away from a communist economic system
toward a free market
system so that farmers are free to
grow and market their crops as they decide..
China leads in production of peanuts having a share of about 32.95%
of overall world production, followed by India (18%) and the United
States of America (6.8%).
Top ten producers of peanuts - 2008/2009
Thousands of peanut cultivars
with four major Cultivar Groups
most popular: Spanish, Runner, Virginia, and Valencia. There are
also Tennessee Red and Tennessee White groups. Certain Cultivar
Groups are preferred for particular uses because of differences in
flavor, oil content, size, shape, and disease
resistance. For many uses
the different cultivars are interchangeable. Most peanuts marketed
in the shell are of the Virginia type, along with some Valencias
selected for large size and the attractive appearance of the shell.
Spanish peanuts are used mostly for peanut candy, salted nuts, and
. Most Runners are used
to make peanut butter.
Peanut leaves and freshly dug
The various types are distinguished by branching habit and branch
length. There are numerous varieties of each type of peanut. There
are two main growth forms, bunch and runner. Bunch types grow
upright, while runner types grow near the ground.
Each year new cultivars of peanuts are bred and introduced.
Introducing a new cultivar may mean change in the planting rate,
adjusting the planter, harvester, dryer, cleaner, sheller, and
method of marketing.
The small Spanish types are grown in South Africa, and in the
southwestern and southeastern U.S. Prior to 1940, 90% of the peanuts grown in
USA were Spanish types, but the trend since then has
been larger seeded, higher yielding, more disease resistant cultivars.
peanuts have a higher oil content than other types of peanuts and
in the U.S. are now primarily grown in Oklahoma and Texas.
Cultivars of the Spanish group include "Dixie Spanish", "Improved
Spanish 2B", "GFA Spanish", "Argentine", "Spantex", "Spanette",
"Shaffers Spanish", "Natal Common (Spanish)", "White Kernel
Varieties", "Starr", "Comet", "Florispan", "Spanhoma", "Spancross",
"OLin", "Tamspan 90", "AT 9899-14", "Spanco" "Wilco I", "GG 2", "GG
4" and "TMV 2".
Since 1940, the southeastern U.S. region has seen a shift to
production of Runner group peanuts. This shift is due to good
flavor, better roasting characteristics and higher yields when
compared to Spanish types leading to food manufacturers' preference
for use in peanut butter and salting. Georgia's production is now
almost 100% Runner type.
Cultivars of Runners include "Southeastern Runner 56-15", "Dixie
Runner", "Early Runner", "Virginia Bunch 67", "Bradford Runner",
"Egyptian Giant" (also known as "Virginia Bunch" and "Giant"),
"Rhodesian Spanish Bunch" (Valencia and Virginia Bunch), "North
Carolina Runner 56-15", "Virugard", "Georgia Green", "Tamrun 96",
"Flavor Runner 458", "Tamrun OL01", "Tamrun OL02" and "AT-108".
Roasted peanuts as snack food
The large seeded Virginia Group peanuts are grown in the following
US states: Virginia, North Carolina, Tennessee, Texas, New Mexico,
Oklahoma, and parts of Georgia. They are increasing in popularity
due to demand for large peanuts for processing, particularly for
salting, confections, and roasting in the shells.
Virginia Group peanuts are either bunch or running in growth habit.
The bunch type is upright to spreading. It attains a height of ,
and a spread of , with rows that seldom cover the ground. The pods
are borne within 5 to 10 cm of the base of the plant.
Cultivars of Virginia type peanuts include NC 7, NC 9, NC 10C, NC-V
11, VA 93B, NC 12C, VA-C 92R, Gregory, VA 98R, Perry, Wilson, Hull,
AT VC-2 and Shulamit.
Valencia Group peanuts are coarse, and they have heavy reddish
stems and large foliage. In the U.S. large commercial production is
primarily in Eastern New
Mexico, especially in and around Portales, New
Mexico, but they are grown on a small scale elsewhere in
the South as the best flavored and preferred type for boiled peanuts.
They are comparatively
tall, having a height of and a spread of . Peanut pods are borne on
pegs arising from the main stem and the side branches. Most of the
pods are clustered around the base of the plant, and only a few are
found several inches away. Valencia types are three seeded and
smooth, with no constriction between the seeds. Seeds are oval and
tightly crowded into the pods. There are two strains, one with
flesh and the other with red seeds. Typical seed weight is 0.4 to
Tennessee Red and Tennessee White groups
These are alike, except for the color of the seed. The plants are
similar to Valencia types, except that the stems are green to
greenish brown, and the pods are rough, irregular, and have a
smaller proportion of kernels.
Peanuts are found in a wide range of
Edible peanuts account for two-thirds of the total peanut use in
the United States. Popular confections include salted peanuts,
, candy bars
, and cups
, and shelled nuts (plain/roasted). Salted peanuts are
usually roasted in oil and packed in retail size, plastic bags or
hermetically sealed cans. Dry roasted, salted peanuts are also
marketed in significant quantities. Peanuts are often a major
ingredient in mixed nuts because of their inexpensiveness compared
to Brazil nuts, cashews, walnuts, and so on. The primary use of
peanut butter is in the home, but large quantities are also used in
the commercial manufacture of sandwiches, candy, and bakery
products. Boiled peanuts
preparation of raw, unshelled green peanuts boiled in brine
and typically eaten as a snack in the southern
United States where most peanuts are grown. More recently, peanuts
can be fried, where they can be eaten both shell and nut. Also
peanuts are used in cosmetics, nitroglycerin, plastics, dyes and
paints (See George Washington
is often used in cooking,
because it has a mild flavor and its relatively high cooking
temperature. It's high monounsaturated content makes it
heart-healthy and resistant to rancidity.There are several types of
peanut oil including: aromatic roasted peanut oil, refined peanut
oil, extra virgin or cold pressed peanut oil and peanut extract.
Studies have shown that refined peanut oil is safe for peanut
allergic individuals because the protein is destroyed during the
processing. In fact, refined peanut oil is exempt from allergen
is popular with culinary
chefs because its high in protein content makes it an ideal flavor
enhancer. Peanut flour is also used as a gluten-free solution and
is lower in fat than peanut butter.
Peanuts are common ingredients in Peruvian Creole cuisine
reflecting the marriage of native ingredients and ingredients
introduced by Europeans. In one example peanuts are roasted along
with hot peppers (both native to South America) and blended with
roasted onions, garlic, and oil (all of European origin) to make a
smooth sauce poured over boiled potatoes. This dish is especially
famous in the city of Arequipa and is known as "papas con ocopa".
Another example combines a similar mixture with sautéed seafood or
boiled and shredded chicken in the form of a fricassee. These
dishes are generally known as "Ajis" such as "Aji de Pollo" "Aji de
Mariscos". One may find that not all cooks use peanuts in seafood
"ajis". The combination of ground roasted peanuts suggests some
Moorish and Middle Eastern influence in modern Peruvian cuisine,
presumably through the Spanish conquistadores. It is well
documented that Arab cuisine
extensive use of ground and pastes of almonds, pine nuts and other
nuts combined with rice, meats and vegetables to arrive to dishes
like Rice Pilaf. In the Levantine, traditional Arab, Catalan, and
Basque cuisines there is also a wide use of ground nuts. Although
the peanut is not a nut it may be argued that the Spanish used the
peanut along with local Peruvian ingredients to emulate their
ancestral cuisine in the absence of almonds and pine nuts. Peanuts
are also widely used in Southeast
cuisine, particularly Indonesia
, where it is typically made
into a spicy sauce
. Peanuts originally
came to Indonesia from the Philippines, where the legume came from Mexico in times of
Common Indonesian peanut-based dishes
, all vegetable salads
mixed with peanut sauce, and the peanut-based dipping sauce for
are a popular Chinese snack and appetizer. Peanuts are also used
in the Mali meat stew
maafe, and in many sauces for South American
meat dishes, especially rabbit.
Peanuts are used to help malnutrition. Plumpy
and Medika Mamba are a high protein, high energy and high
nutrient peanut-based paste that were developed to be used as a
therapeutic food to aid in famine relief. Organizations like the
World Health Organization, UNICEF, Project Peanut Butter and
Doctors Without Borders have used these products to help save
malnourished children in developing countries.
Like snack in India
Peanuts or peanut shells are boiled in little salt water and eat
them after good boil. And Indians
peanut or peanut shells to brown color and eat them. or Indians
roast peanut shells in oil with chillies and
eat them. You get them in Indian
in India and world.
Peanuts are also very widely sold for garden bird
feeding. Low grade or culled peanuts not suitable
for the edible market are used in the production of peanut
Peanuts have a variety of industrial end uses. Paint, varnish,
lubricating oil, leather dressings, furniture polish, insecticides,
are made from peanut
oil. Soap is made from saponified
oil, and many cosmetics contain peanut oil and its derivatives. The
protein portion of the oil is used in the manufacture of some
Peanut shells are put to use in the manufacture of plastic,
wallboard, abrasives, and fuel. They are also used to make
cellulose (used in rayon
and paper) and
Peanut plant tops are used to make hay
protein cake (oilcake meal) residue from oil processing is used as
an animal feed and as a soil fertilizer.
Peanuts can also be used like other legumes and grains to make a
lactose-free milk-like beverage, Peanut
Peanuts are nutrient rich, providing over 30 essential nutrients
and phytonutrients. Peanuts are a good source of niacin, folate,
fiber, magnesium, vitamin E, manganese and phosphorus. They also
are naturally trans fat, sodium free and provide seven grams of
protein per serving, the most protein of any nut.
While peanuts are considered high in fat, they primarily contain
“good” fats also known as unsaturated fats. One serving of peanuts
contains 11.5 g unsaturated fat and 2 g of saturated fat. In fact,
peanuts have been linked well enough to their heart healthy
benefits, in 2003, the Food and Drug Administration released a
health claim recognizing peanuts in helping maintain your
The claim states:Scientific evidence suggests, but does not
prove, that eating 1.5 ounces per day of most nuts, including
peanuts as part of a diet low in saturated fat and cholesterol, may
reduce the risk of heart disease.
Some brands of peanut butter are fortified with Omega-3
in the form of flaxseed oil
to balance the ratio of Omega-3
Peanuts are a good source of niacin
contribute to brain health, brain circulation and blood flow.
Peanuts and antioxidants
Recent research on peanuts and nuts in general has found antioxidants
and other chemicals that may
provide health benefits. New research shows peanuts rival the
antioxidant content of many fruits. Roasted peanuts rival the
antioxidant content of blackberries and strawberries, and are far
richer in antioxidants than apples, carrots or beets. Research
conducted by a team of University of Florida scientists, published
in the journal Food Chemistry, shows that peanuts contain high
concentrations of antioxidant polyphenols
, primarily a compound called
, and that roasting
can increase peanuts' p-coumaric acid levels, boosting their
overall antioxidant content by as much as 22%.
Peanuts as a source of resveratrol
Peanuts are a significant source of resveratrol
, a chemical studied for potential
anti-aging effects and also associated with reduced cardiovascular disease
It has recently been found that the average amount of resveratrol
in one ounce of commonly eaten peanuts without the skin (15 whole
peanut kernels) is 73 μg. This means that ounce for ounce, peanuts
contain almost 30 times as much resveratrol as grapes, which often
are touted as being one of the few good sources of the
Peanuts and coenzyme Q10
Peanuts are a source of Coenzyme Q10
along with oily fish
Shelled Peanuts with skin
Although many people enjoy foods made with peanuts, some people
(0.6% - 1% of the US population) have mild to severe allergic reactions
. For some people with peanut
allergy, exposure can cause fatal anaphylactic shock
. For these individuals,
eating a small amount of peanut or just breathing the dust from
peanuts can cause a fatal reaction. An allergic reaction also can
be triggered by eating foods that have been processed with machines
that have previously processed peanuts, making the avoidance of
such food difficult.
A theory of the development of peanut allergy has to do with the
way that peanuts are processed in North America versus other
countries like China and India. Peanuts are widely eaten in China
and India but peanut allergies are almost unheard of there.
According to a 2003 study, roasting peanuts, as more commonly done
in North America, causes the major peanut allergen Ara h2 to become
a stronger inhibitor of the digestive enzyme trypsin
, making it more resistant to digestion.
Additionally, this allergen has also been shown to protect Ara h1,
another major peanut allergen, from digestion - a characteristic
further enhanced by roasting.
Another theory, called the Hygiene Hypothesis, states that a lack
of early childhood exposure to infectious agents like germs and
parasites, could be causing the increase of food allergies.
Recent (2008) studies comparing age of peanut introduction in Great
Britain with introduction in Israel appear to show that delaying
exposure to peanuts can dramatically increase the risk of
developing peanut allergies.
Though the allergy can last a lifetime, another 2003 study
indicates that 23.3% of children will outgrow a peanut
Peanut allergy has been associated
with the use of skin
preparations containing peanut oil among children, but the evidence
is not regarded as conclusive. Peanut allergies have also been
associated with family history and intake of soy products.
Some school districts
peanuts,. There are experimental techniques which appear to have
desensitized some allergic individuals.. The most popular
technique, oral immunotherapy, works to create desensitization in
those peanut allergic by feeding them small amounts of peanut until
their body builds a defense to it.
Research indicates that refined peanut oil will not cause allergic
reactions in most people with peanut allergies. However, crude
(unrefined) peanut oils are strongly flavoured, and have been shown
to contain protein, which may cause allergic reactions.
In a randomized, double-blind
, crossover study
, 60 people with proven
peanut allergy were challenged with both crude peanut oil and
refined peanut oil. The authors conclude that “Crude peanut oil
caused allergic reactions in 10% of allergic subjects studied and
should continue to be avoided.” They also state that, “Refined
peanut oil does not seem to pose a risk to most people with peanut
allergy.” However, they point out that refined peanut oil can still
pose a risk to peanut-allergic individuals if oil that has
previously been used to cook foods containing peanuts is
Peanuts and aflatoxin
Peanuts may be contaminated with the mold
produces a carcinogenic
. Lower quality
specimens, particularly where mold
are more likely to be contaminated. USDA tests every truckload of
raw peanuts for aflatoxin, any containing aflatoxin levels of more
than 20 parts per billion are destroyed. The Peanut Industry has
manufacturing steps in place to ensure all peanuts are inspected
for aflatoxin. Peanuts are also processed at a high temperature to
ensure any microorganisms are killed.
U.S. Department of Agriculture (USDA) program
George Washington Carver
often credited with inventing 300 different uses for peanuts
(which, contrary to popular belief, did not include peanut butter
but did include salted peanuts).
Carver was one of many USDA researchers who encouraged cotton
farmers in the South to grow peanuts instead
of, or in addition to cotton, because cotton had depleted so much
nitrogen from the soil, and one of the peanut's properties as a
legume is to put nitrogen back into the soil (a process known as
). Rising demand
for peanuts in the early 1900s was not due to Carver's products but
to a shortage of plant oils during World War I and the growing
popularity of peanut butter, roasted peanuts and peanut candies.
Peanut products originating around the early 1900s include many
brands still sold today such as Cracker
candy bar (1920), Baby Ruth
candy bar (1920), Butterfinger
candy bar (1923), Mr. Goodbar
candy bar (1925), Reese's Peanut Butter Cup
Peanuts were designated by the U.S. Congress
to be one of
America's basic crops. In order to protect domestic industry by
keeping prices artificially high, the United
States Department of Agriculture (USDA) aids peanut farmers through commodity
In the 2008 Farm Bill, the marketing quota for
peanuts was eliminated and the Price Support Program was switched
to a Direct and Counter-Cyclical Payment Program. Direct and
counter-cyclical payments provide benefits to producers with
eligible historical production of peanuts whenever the effective
price is less than the targeted price.
producers/exporters of peanuts are the United States, Argentina, Sudan, Senegal, and Brazil.
These five countries account for 71% of total world exports. In
recent years, the United States has been the leading exporter of
peanuts. The major peanut importers are the European Union
(EU), Canada, and Japan. These
three areas account for 78% of the world's imports.
Although India and China are the world's largest producers of
peanuts, they account for a small part of international trade
because most of their production is consumed domestically as
. Exports of peanuts from India
and China are equivalent to less than 4% of world trade.
Ninety percent of India's production is processed into peanut oil.
Only a nominal amount of hand-picked select-grade peanuts are
exported. India prohibits the importation of all oil seeds,
The European Union is the largest consuming region in the world
that does not produce peanuts. All of its consumption is supplied
by imports. Consumption of peanuts in the EU is primarily as food,
mostly as roasted-in-shell peanuts and as shelled peanuts used in
confectionery and bakery products.
The average annual U.S. imports of peanuts are less than 0.5% of
U.S. consumption. Two thirds of U.S. imports are roasted, unshelled
peanuts. The major suppliers are Taiwan, Malaysia, Hong Kong, Mainland
China, and Canada. The principal suppliers of shelled peanut
imports are Argentina and Canada.
Most of Canada's peanut butter
is processed from Chinese peanuts. Imports of peanut butter from
Argentina are in the form of a paste and must be further processed
in the U.S. Other minor suppliers of peanut butter
include Malawi, China,
India, and Singapore.
Approximately 50% of all peanuts produced in
the United States are grown within a radius of Dothan,
Dothan is home to the National Peanut
Festival established in 1938 and held each fall to honor peanut
growers and celebrate the harvest.
- Berrin, Katherine & Larco Museum. The Spirit of Ancient
Peru: Treasures from the Museo Arqueológico Rafael Larco Herrera.
New York: Thames and Hudson, 1997.
- Timothy H. Sanders, Robert W. McMichael, Jr., Keith W. Hendrix
(2000): Occurrence of resveratrol in edible peanuts. J Agric
Food Chem 48:1243 -1246. link
- Soheila J. Maleki, Olga Viquez, Thomas Jacks, Hortense Dodo,
Elaine T. Champagne, Si-Yin Chung and Samuel J. Landry. "The major
peanut allergen, Ara h 2, functions as a trypsin inhibitor, and
roasting enhances this function." Journal of Allergy and
Clinical Immunology 112.1 (July 2003): 190-195.
- Food allergy advice may be peanuts,
magazine, December 6, 2008
- Høst A et al. Dietary prevention of allergic diseases in
infants and small children. 2008. Pediatric Allergy and Immunology,
Vol. 19, p. 1-4
- David M. Fleischer, Mary Kay Conover-Walker, Lynn Christie, A.
Wesley Burks and Robert A. Wood. "The natural progression of peanut
allergy: Resolution and the possibility of recurrence." Journal
of Allergy and Clinical Immunology 112.1 (July 2003):
- Lack G, Fox D, Northstone K, Golding J. N Engl J Med. 2003;
- ibid. (for "family history" and "use of soy products")
- Hoffman DR, Collins-Williams C. Cold-pressed peanut oils may
contain peanut allergen. J Allergy Clin Immunol 1994;
- Hourihane JO, Bedwani SJ, Dean TP, Warner JO. Randomised,
double blind, crossover challenge study of allergenicity of peanut
oils in subjects allergic to peanuts. British Medical
Journal 1997 314: 1084 (12 April) online
- Morinaga & Co., Proportion of aflatoxin B1 contaminated
kernels and its concentration in imported peanut samples 2001
Aug;42(4):237-42. (PMID 11817138)
- List of By-Products From Peanuts By George Washington
Carver (as compiled by the Carver Museum)
- Handy, R.B. 1895. Peanuts: Culture and Uses. USDA Farmers'
- Newman, C.L. 1904. Peanuts. Fayetteville, Arkansas: Arkansas
Agricultural Experiment Station.
- Beattie, W.R. 1909. Peanuts. USDA Farmers' Bulletin 356.
- Ferris, E.B. 1909. Peanuts. Agricultural College, Mississippi:
Mississippi Agricultural Experiment Station.
- Beattie, W.R. 1911. The Peanut. USDA Farmers' Bulletin
- Rich, J.P. 1915. Uses of the Peanut on the Home Table. Farmer's
Bulletin 13. University of Texas, Austin.
- Carver, G.W. 1916. How to Grow the Peanut and 105 Ways of
Preparing it for Human Consumption. Tuskegee Institute Experimental
Station Bulletin 31. on-line
- Pages 412-413 of "Crop Production: Evolution, History, and
Technology." by C. Wayne Smith, 1995. (ISBN 0-471-07972-3)
- Citizens Against Government Waste (CAGW), "Peanut
- International Crops Research Institute for the
Semi-Arid Tropics (ICRISAT), "Groundnut (peanut)"
- Putnam, D.H. & Oplinger, E.S., "Peanut", 1991, Center for
Alternative Plant and Animal Products, University of Minnesota, St.
- University of Georgia, "World Geography of the Peanut",