Lemon

This article is about the fruit. For other uses, see Lemon (disambiguation)

Lemon
Citrus x limon
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Subclass:	Rosidae
Order:	Sapindales
Family:	Rutaceae
Genus:	Citrus
Species:	C. × limon
Binomial name
Citrus × limon (L.) Burm.f.

The lemon (Citrus × limon) is a hybrid citrus tree of cultivated origin. The fruit are used primarily for their juice, though the pulp and rind (zest) are also used, primarily in cooking or mixing. Lemon juice is about 5% citric acid, which gives lemons a sour taste and a pH of 2 to 3. This acidity makes lemon juice a cheap, readily available acid for use in educational chemistry experiments.

Description

lemon tree

A lemon tree can grow up to 10 meters (33 feet), but they are usually smaller. The branches are thorny, and form an open crown. The leaves are green, shiny and elliptical-acuminate. Flowers are white on the outside with a violet streaked interior and have a strong fragrance. On a lemon tree, flowers and ripe fruits can be found at the same time.

Lemon fruit are ovoid with a pointed tip at the end. When ripe, they have a bright yellow skin, a layer of pith underneath and a paler yellow segmented interior. Small Seeds commonly known as 'pips' are found within the fruit.

Cultivation

Lemon fruit and flower

Lemons grow in tropical and sub-tropical climates and cannot withstand frosts and very cold temperatures. Their favored temperature is between 15–30 °C (60–85 °F) and they need ample quantities of sunlight. They thrive in fertile, well drained soils, but are notable for tolerating very poor, infertile soil, such as sand. Lemons need plenty of water but should be allowed to dry out between waterings. Propagation is often by grafting as the stock is vulnerable to cankers and dry rot.

Lemons are grown commercially in Spain, Portugal, Italy,Turkey, and other Mediterranean countries, Argentina, India, Brazil and the United States. They can be grown as plants in the garden as well as in containers if they are pruned to keep a small form.

Several cultivated varieties of lemon have been produced. Some of the more common are Eureka, Lisbon, Fino and Verna. There are also some lemon hybrids including the Meyer lemon.

History

William-Adolphe Bouguereau Girl Holding Lemons

The lemon is a cultivated hybrid deriving from wild species such as the citron and mandarin. When and where this first occurred is not known. The citron, apparently the fruit described in Pliny's Natural History (XII, vii.15) as the malum medicum — the "medicinal fruit" — seems to have been the first citrus fruit known in the Mediterranean world. Depictions of citrus trees appear in Roman mosaics of North Africa, but the first unequivocal description of the lemon, is found in the early tenth-century Arabic treatise on farming by Qustus al-Rumi. At the end of the twelfth century, Ibn Jami’, personal physician to the Muslim leader Saladin, wrote a treatise on the lemon, after which it is mentioned with greater frequency in the Mediterranean. However, it is believed that the first lemons were originally cultivated in the hot, semi-arid Deccan Plateau in Central India.

The origin of the name "lemon" is through Persian (لیمو Limu), akin to the Sanskrit nimbuka. They were cultivated in Genoa in the mid-fifteenth century, and appeared in the Azores in 1494. More recent research has identified lemons in the ruins of Pompeii. Lemons were once used by the British Royal navy to combat scurvy, as they provided a large amount of vitamin C.

In food preparation

Lemons

Lemon, raw, without peel

Nutritional value per 100 g (3.5 oz)
Energy	121 kJ (29 kcal)
Carbohydrates	9 g
Sugars	2.5 g
Dietary fiber	2.8 g
Fat	0.3 g
Protein	1.1 g
Vitamins and minerals Vitamins Quantity %DV† Vitamin C 59% 53 mg
Other constituents	Quantity
Water	89 g
Citric acid	5 g
†Percentages estimated using US recommendations for adults, except for potassium, which is estimated based on expert recommendation from the National Academies.

Both lemons and limes are regularly served as lemonade or limeade, its equivalent, or as a garnish for drinks such as iced tea or a soft drink, with a slice either inside or on the rim of the glass. Only lemons, however, are used in the Italian liqueur Limoncello. A wedge of lemon is also often used to add flavor to water.

Lemon juice is typically squeezed onto fish dishes; the acidic juice neutralizes the taste of amines in fish by converting them to nonvolatile ammonium salts.

In addition, lemon juice is widely used, along with other ingredients, when marinating meat before cooking: the acid provided by the juice partially hydrolyzes the tough collagen fibers in the meat (tenderize the meat). The juice, however, is not an effective antibiotic, as is commonly thought.

Lemon juice is also sprinkled on cut fruit, such as apples, to prevent oxidation which would otherwise rapidly darken the fruit, making it less appetizing. Some people like to eat lemons as fruit, however water should be consumed afterwards to wash the citric acid and sugar from the teeth, which might otherwise promote tooth decay and many other dental diseases. It can be used on its own or with oranges to make marmalade.

There is a belief in Ayurvedic medicine that a cup of hot water with lemon juice in it tonifies and purifies the liver.

Chemistry and health

limonene

lemons and other citrus fruits contain amounts of different chemicals and are thought to have some health benefits. They contain a terpene called limonene which gives their Characteristic lemon smell and taste. Lemons contain significant amounts of citric acid, this is why they have a low ph and a sour taste. They also famously contain Vitamin C (Ascorbic acid) which is essential to human health. 100 milliliters of lemon juice contains approximately 50 milligrams of vitamin C and 5 grams of citric acid.

Some sources state that lemons contain unique flavonoid compounds that have antioxidant and anti-cancer properties . These may be able to deter cell growth in cancers. Limonins found in Lemons could also be anti-carcinogens.

Lemon battery

Main article: Lemon battery

A common school experiment involving lemons is to attach electrodes and use them as a battery to power a light. The electricity generated may also be used to power a motor to move the lemons (on wheels) like a car or truck. These experiments also work with other fruit like apples and with potatoes.

Lemon alternatives

Several other plants have a similar taste and smell to lemons. In recent times, the Australian bush food Lemon myrtle has become a popular alternative to lemons. The crushed and dried leaves and edible essential oils have a strong, sweet lemon taste, but contain no citric acid. Lemon myrtle is popular in foods that curdle with lemon juice, such as cheesecake and ice cream.

Many other plants are noted that have a lemon-like taste or scent. Among them are Cymbopogon (lemon grass), Lemon balm, Lemon thyme, Lemon verbena, Scented geraniums, certain cultivars of basil, and certain cultivars of mint

In popular culture

• The Lemon Song by Led Zeppelin
• Lemon by U2

See also

• Citrus, a genus of flowering plants in the family Rutaceae.
• Cymbopogon, commonly known as lemon grass.
• Orange (fruit), a related citrus tree and fruit.
• Lime (fruit), multiple citruses with green to yellow fruit.
• Lemonade
• Extract, technique of extraction and chemicals in lemon oil.
• Limonene, Chemical that gives the lemon smell.

References

• Lemon Herbs
• Lemon heath benefits

External links

• (Purdue University) Morton, Julia F. 1987. "Lemon". pp. 160–168, in Fruits of warm climates. (Julia F. Morton, Miami)
• Andrew M. Watson, 1983. Agricultural Innovation in the Early Islamic World: The Diffusion of Crops and Farming Techniques, 700-1100. (Cambridge: Cambridge University Press) pp 42-50