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How The Peanut Plant Grows
Types of Peanuts
Where Peanuts Grow
How Peanuts are Planted and Harvested
Peanut Grading, Shelling and Blanching
How Peanuts are Marketed
Peanut Butter/Peanut Spread
Roasted Peanuts/Snack Peanuts
Oil and Other Peanut Products
Non-Food Uses for Peanuts
How You Can Grow A Peanut Plant
The peanut is unusual because it flowers above the ground, but fruits below
the ground. Typical misconceptions of how peanuts grow place them on trees (like
walnuts or pecans) or growing as a part of a root, like potatoes.
Peanut seeds (kernels) grow into a green oval-leafed plant about 18 inches tall which develop delicate flowers around the lower portion of the plant. The flowers pollinate themselves and then lose their petals as the fertilized ovary begins to enlarge. The budding ovary or "peg" grows down away from the plant, forming a small stem, which extends to the soil. The Peanut embryo is in the tip of the peg, which penetrates the soil. The embryo turns horizontal to the soil surface and begins to mature taking the form of peanut. The plant continues to grow and flower, eventually producing some 40 or more mature pods. From planting to harvesting, the growing cycle takes about four to five months, depending on the type or variety. The peanut is a nitrogen-fixing plant; its roots form modules which absorb nitrogen from the air and provides enrichment and nutrition to the plant and soils.
come in many varieties, there are four basic market types: Runner, Virginia,
Spanish and Valencia. Each of the peanut types is distinctive in size, flavor,
and nutritional composition.
Runners have become the dominant type due to the introduction in the early 1970's of a new runner variety, the Florunner, which was responsible for a spectacular increase in peanut yields. Runners have rapidly gained wide acceptance because of the attractive, uniform kernel size. Fifty-four percent of the runners grown are used for peanut butter. Runners are grown mainly in Georgia, Alabama, Florida, Texas and Oklahoma.
Virginias have the largest kernels and account for most of the peanuts roasted and processed in-the-shell. When shelled, the larger kernels are sold as snack peanuts. Virginias are grown mainly in southeastern Virginia and northeastern North Carolina.
Spanish-type peanuts have smaller kernels covered with a reddish-brown skin. They are used predominantly in peanut candies, with significant quantities used for snack nuts and peanut butter. They have a higher oil content than the other types of peanuts which is advantageous when crushing for oil. They are primarily grown in Oklahoma and Texas.
Valencias usually have three or more small kernels to a pod and are covered in a bright-red skin. They are very sweet peanuts and are usually roasted and sold in-the-shell. They are also excellent for fresh use as boiled peanuts. New Mexico is the primary producer of Valencia peanuts.
Within each four basic types of peanuts, there are several "varieties" for seed and production purposes. Each variety contains distinct characteristics which allows a producer to select the peanut that is best suited for its region and market.
Peanuts are grown in the warm climates of Asia, Africa, Australia, and North and South America. India and China together account for more than half of the world's production. The United States has about 3% of the world acreage of peanuts, but grows nearly 10% of the world's crop because of higher yields per acre. Other major peanut growing countries include Senegal, Sudan, Brazil, Argentina, South Africa, Malawi, and Nigeria.
the United States, nine states grow 99% of the U. S. peanut crop: Georgia (which
grows about 39% of all U. S. peanuts), followed by Texas, Alabama, North Carolina,
Florida, Oklahoma, Virginia, South Carolina and New Mexico. These states are
grouped into three regions. The Georgia-Florida-Alabama region (Southeast) grows
mostly the medium-kernel Runner peanuts. The Southwest region (Texas-Oklahoma-New
Mexico) grows Spanish and Runner. The Virginia-Carolinas area grows mostly the
large-kernel Virginia type peanut. About 55% of all U. S. peanuts are grown
in the Southeast, with the Virginia/Carolina area accounting for 14% and the
Southwest, about 30%.
Area Harvested, Yield, and Production by State
|1,000 Acres||1,000 Acres||
Peanut Crop Summary: Area Planted and Harvested, Yield, and Production, United States, 1990-2000
Source: National Agricultural Statistics Service, USDA
|Yield Per Acre||Production|
|1,000 acres||1,000 acres||Pounds||1,000 pounds|
are planted and harvested with specialized machinery. Peanut seeds are planted
about two inches deep, one every three or four inches, in rows about three feet
apart. The seeds do best in sandy soil, especially soil rich in calcium. When
the soil temperature is warm (65-70 F.) given enough water the seeds will sprout.
In about two weeks, the first "square" of four leaflets will unfold
above the peanut field. Thirty to forty days after emergence the plants bloom,
"pegs" form and enter the soil. The peanut shells and kernels develop
and mature during the next 60 to 70 day period. Depending on the variety, 120
to 160 frost free days are required for a good crop.
When the plant has matured and the peanuts are ready to be harvested, the farmer waits until the soil is neither too wet or too dry before digging. Whenconditions are right, the farmer drives his digger up and down the green rows of peanuts plants. The digger has long blades that run four to six inches under the ground. It loosens the plant and cuts the tap root. Just behind the blade, a shaker lifts the plant from the soil, gently shakes the dirt from the peanuts, rotates the plant, and lays the plant back down in a "windrow," peanuts up and leaves down. When dug, peanuts contain 25 to50% moisture, which must be dried to 10% or less for storage. Peanuts are generally left in the windrows to dry for 2 or more days in the field, then threshed or combined.
The farmer drives his combine over the windrows. The combine lifts the plants, separates the peanuts from the vine, blows them into a hopper on the top of the machine, and lays the vine back down in the field. The peanuts are then dumped into wagons and cured to 10% moisture with warm air forced up through the floors of the wagons. The peanuts are then taken to be sold at nearby peanut buying stations.
At the shelling company buying station, peanuts are sampled and graded by the Federal-State Inspection Service to determine their value. The inspectors establish the meat content, size of pods, kernel size, moisture content, damaged kernels and foreign material. The results of the inspection determine the overall quality and value of each load.
After the peanuts are purchased by the sheller, they are placed in dry storage for eventual sale to processors and manufacturers. At the shelling plant, peanuts are taken from storage and cleaned; dirt, rocks, bits of vines and other debris are removed. If they are to be sold in their shells, the peanuts may also pass through a machine that cuts off any remaining stems on the shells. (About 10% of the peanut crop is sold as in-shell peanuts - usually the Virginia and Valencia types.) To sort for size, the peanuts travel over sizing screens that permit the smaller pods to fall through.
Peanuts to be shelled are placed in slotted drums containing screens of different sizes. Rotating peanuts rub against each other until the shells are opened and the kernels fall out. The kernels are sized on screens that permit the smaller kernels to fall through. The shelled peanuts are cleaned again to remove foreign materials. This is done with density separators, electronic color sorters and by visual inspection to ensure that only the best peanuts reach the market. The peanut kernels are then sized, graded and bagged for market.
From the sheller, peanuts are cleaned again and "blanched" before they are used in most peanut foods. Blanching is simply the removal of the reddish skin covering the kernels. In whole-nut or split-nut dry blanching, the kernels travel through warm air for a period of time to loosen the skins. Then the kernels go through a blanching machine where large rollers rub the surfaces of the kernels until the skins fall off. These kernels are checked with electronic color sorters to ensure that blanching is complete.
Peanuts are sold
in various ways. A peanut broker or a sheller may sell the peanuts to the end
user - or, a peanut dealer or commission merchant in a large market may buy
the peanuts. Peanuts are usually sold to a manufacturer or "end user,"
who then converts the peanuts to consumer products and markets the peanuts to
Roughly three-quarters of the peanuts grown in the U. S. are used domestically, predominantly as edible products. About one-forth of all U.S. grown peanuts are exported to other countries. Exported peanuts are usually shipped raw, both shelled and in the shell. The major buyers of U. S. peanuts are found in Western Europe, Canada and Japan.
of all edible peanuts produced in the United States are used to make peanut
butter and peanut spreads. By law and industry standard, any product labeled
"peanut butter" in the U. S. must be at least 90% peanuts. The remaining
10% may be salt, sweetener and an emulsifier (hardened vegetable oil which prevents
the peanut oil from separating and rising to the top).
Other similar products which don't subscribe to the 90%/10% rule are labeled peanut spread. Many are reduced fat products with added vitamins and minerals. These standards are subscribed to by the industry to assure consumers of uniformly nutritious products.
The ancient South American Indians were the first to make and eat peanut butter, and one of the peanut foods invented by Dr. George Washington Carver was similar to peanut butter. 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. Also during that period (1895), Dr. John Harvey Kellogg (of breakfast cereal fame) patented the process of making peanut butter for the patients at his Battle Creek Sanitarium, a health food retreat in Michigan.
Basically, all peanut butter is made by a similar process. First the raw, shelled peanuts are roasted and cooled, then the skins are removed (blanched.) Some manufacturers split the kernels and remove the heart of the peanut as well. The hearts can be saved to make peanut oil and the skins left over from blanching can be sold for animal feed. The blanched peanut kernels are electronically sorted or hand picked one last time to be sure only good, wholesome kernels are used in peanut butter.
The peanuts are ground, usually through two grinding stages, to produce a smooth, even-textured butter. The peanuts are heated during the grinding to about 170 degrees F . Once the emulsifiers are added and mixed, the butter is cooled rapidly to 120 degrees F or below. This crystallizes the emulsifiers, thus trapping the peanut oil that was released by the grinding. To make chunky peanut butter, peanut granules are added to the creamy peanut butter. The peanut butter is then packed into containers for sale at stores.
To be roasted in the shell, peanuts are cooked at medium heat for about 15 minutes. They may be plain roasted or seasoned roasted-in-the-shell. The most popular are salted in-the-shell, however the new flavors - cajun and jalapeno are getting accolades from consumers as well. To season peanuts in the shell - prior to roasting- the peanuts are washed and then the seasonings, which are dissolved in water, are forced through the shells by a pressure process. When dried during roasting, the seasonings remain inside the shells. Most often, snack peanuts are shelled, roasted, blanched and salted, (although Spanish peanuts are usually roasted with their skins on.) Peanuts may be roasted in oil or by a dry-roasting process. Peanuts are oil-roasted in continuous cookers that take a steady stream of peanuts through hot oil for about five minutes. After draining, the kernels are salted evenly. Dry-roasted peanuts are cooked in a large oven by dry, hot forced air after which spicy seasonings are applied. The roasted peanuts are then packed in containers ranging in size from bags holding a handful, to large cans and jars. Frequently, peanuts are mixed with other nuts and dried fruits for "health-food" snacks.
Peanuts are used in candy-making in a seemingly infinite number of ways. A large variety of candy bars combine peanuts (whole, chopped or as butter) with such treats as chocolate, nougat, marshmallow, caramel, other nuts and dried fruits. Peanut brittle and chocolate-covered peanuts are always popular. The high protein content of peanuts make them ideal for high energy snacks. Six of the top ten candy bars sold in the U.S. contain peanuts and/or peanut butter.
Applying pressure to peanuts squeezes out their oil. This oil is excellent for cooking because it is tasteless and can be heated to very high temperatures before it smokes. (450 degrees F, which is hotter than most other cooking oils). With hotter cooking temperatures, food will cook faster and absorb less oil. Peanut oil does not absorb or transfer flavors, so the same oil can be used repeatedly to cook different foods.
Specially processed, defatted peanuts are available as roasted snack peanuts; may be ground into a flour, which can be used to make such foods as high protein drinks and snacks. Or, the defatted nuts may be granulated and added to breakfast or diet bars to raise their protein level.
Partially defatted peanuts can also be flavored to taste and to look (when chopped) like other nuts, such as pecans, almonds and walnuts for use in cooking.
Peanuts can be made into imitation milk, cheese and ice cream. In fact, "cheese" made from peanut milk is nutritionally superior to dairy products in everything except calcium.
Peanut meal (made from the by-product of peanuts pressed for oil) is an important high protein animal feed.
The shells, skins and kernels of peanuts may be used to make a vast variety of non-food products. For example, the shells may be used in wallboard, fireplace logs, fiber roughage for livestock feed and kitty litter; and, the skins may be used for paper making. Peanuts are often used as an ingredient in other products such as detergent, salves, metal polish, bleach, ink, axle grease, shaving cream, face creams, soap, linoleum, rubber, cosmetics, paint, explosives, shampoo, and medicine.
Peanuts should sprout within five to eight days. Continue to keep plant in a warm location exposed to direct sunlight as much as possible. Blooms will likely appear approximately 45 days after the peanut plant has emerged. (Production of peanuts on potted plant is unlikely, but may occur if kept growing for a minimum of three months)