The peanut, also called groundnut, oil nut or monkey nut, is, despite all these names, botanically speaking not a nut, but a legume containing two or three seeds. Like all leguminous plants, the peanut belongs to the family Fabaceae, which includes a number of important agricultural and food plants. It is widely grown in the tropics and subtropics, being important to both small and large commercial producers.
The peanut plant is an annual plant that originated in South America and was spread by the Spaniards in the 16th century in tropical and subtropical areas all over the world. It was most likely first domesticated in Brazil, from where the Portuguese and Spaniards introduced it to Africa, India and Asia. In China, the peanut quickly became the main source of cooking oil, as it contains twice as much fat as soy beans.
It was not until the first half of the 19th century that peanuts began to play an important role in the West, as a source of oil. Due to a major shortage of oil in the first few decades of that century, peanut oil extraction was rapidly industrialized. In 1834 a total of 213 baskets of peanuts were exported from Gambia to England. The following year that number had risen to 47 tons. The number of hectares on which peanuts were planted in India grew by a factor of 70 between 1850 and 1895.
Nowadays, the largest producers of peanuts are China, Israel, the United States, Egypt, Argentina and South Africa. Israel and Egypt produce mainly for export of the raw nuts in shell. China also exports raw nuts in shell, although most of the harvest is exported in husked form or used for the production of peanut oil. In general, they 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.
The peanut is unusual because it has flowers above the ground, but fruits below the ground. Typical misconceptions of how they grow place them on trees (like walnuts or pecans) or growing as a part of a root, like potatoes. In actuality, they are found on leguminous plants, where peanut seeds or kernels grow into a green oval-leafed plant about 18 inches tall.
Peanuts are planted and harvested with specialized machinery. The plant grows flowers, 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. Plants are harvested in September and October, after which they are placed peanut side-up and dried. Excavated peanuts contain 25 to 50 percent moisture and must dry to 10 percent or less before they can be stored.
Unroasted (raw) peanuts can be peeled and eaten. For human consumption, however, it is customary to burn them first. Especially in the winter they are used as food for wild birds. The ones that aren’t fully ripe are also commonly cooked in their skins, especially in the southern United States. They become soft like beans and are eaten with salt or spices (cajun).
Peanuts for consumption are peeled and briefly blanched so that the skin comes off. Next, they are roasted or ground into peanut butter. Peanut sauce and peanut soup are also made from peanuts. They are used in both sweet and savory dishes, or eaten loose, often sweetened or sprinkled with salt. They are also often used in cookies, nuts and other snacks.
The most important reserve substance in a peanut is fat. They have a higher fat content than the seeds of other legumes. In addition to 46% fat (of which 7% saturated) peanuts contain 25% protein and approximately 14% carbohydrates.
Peanuts are sold in various ways. They are usually sold to a manufacturer or “end user,” who then converts them to consumer products and markets them to the public. Exported peanuts are usually shipped raw, both shelled and in the shell.