Lemon

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

Lemon
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Sapindales
Family:	Rutaceae
Genus:	Citrus
Species:	C. × limon
Binomial name
Citrus × limon, often given as C. limon (L.) Burm.f.

The lemon (Citrus × limon) is a small evergreen tree native to Asia, and the tree's ellipsoidal yellow fruit. The fruit's juice, pulp and peel, especially the zest, are used as foods. The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste. The distinctive sour taste of lemon juice makes it a key ingredient in drinks and foods such as lemonade.

History

A lemon tree with fruit and flowers

The origin of the lemon is a mystery, though it is thought that lemons first grew in Southern India, northern Burma, and China. A study of the genetic origin of the lemon reported that it is a hybrid between sour orange and citron.

Lemons entered Europe near southern Italy no later than the 1st century AD, during the time of Ancient Rome. However, they were not widely cultivated. They were later introduced to Persia and then to Iraq and Egypt around 700 AD. The lemon was first recorded in literature in a 10th century Arabic treatise on farming, and was also used as an ornamental plant in early Islamic gardens. It was distributed widely throughout the Arab world and the Mediterranean region between 1000 and 1150.

The first substantial cultivation of lemons in Europe began in Genoa in the middle of the 15th century. The lemon was later introduced to the Americas in 1493 when Christopher Columbus brought lemon seeds to Hispaniola on his voyages. Spanish conquest throughout the New World helped spread lemon seeds. It was mainly used as an ornamental plant and for medicine. In the 18th and 19th centuries, lemons were increasingly planted in Florida and California.

In 1747, James Lind's experiments on seamen suffering from scurvy involved adding vitamin C to their diets with lemon juice.

The origin of the word lemon may be Middle Eastern. One of the earliest occurrences of "lemon" appears in a Middle English customs document of 1420–1421, which draws from the Old French limon, thence the Italian limone, from the Arabic laymūn or līmūn ليمون, and from the Persian līmūn لیمو, a generic term for the fruit of this kind, which is congnative with Sanskrit निम्ब (nimbū, “lime”).

Growing lemons

A lemon tree in Corsica

Lemons are often grafted to more vigorous rootstocks.

Varieties

The Bonnie Brae is oblong, smooth, thin skinned and seedless; mostly grown in San Diego County.

The Bush lemon tree, a naturalized lemon, grows wild in subtropical Australia. It is very hardy, and has a thick skin with a true lemon flavor; the zest is good for cooking. It grows to about 4m in a sunny position.

The Eureka grows year-round and abundantly. This is the common supermarket lemon.

The Femminello St. Teresa, or Sorrento is native to Italy. This fruit's zest is high in lemon oils. It is the variety traditionally used in the making of limoncello.

The Jhambiri (C. jhambiri) (Tan) is a rough lemon which has a lemon yellow exterior and a very sour pulp. It is widely used as a rootstock in South Asia.

The Lisbon is a good quality bitter lemon with high juice and acid levels, the fruits of Lisbon are very similar to Eureka. The vigorous and productive trees are very thorny, particularly when young.

The Meyer lemon is a cross between a lemon and possibly an orange or a mandarin, and was named after Frank N. Meyer, who first discovered it in 1908. Thin-skinned and slightly less acidic than the Lisbon and Eureka lemons, Meyer lemons require more care when shipping and are not widely grown on a commercial basis. Meyer lemons have a much thinner rind, and often mature to a yellow-orange color. Meyer lemons are slightly more frost-tolerant than other lemons.

The Ponderosa lemon is more cold-sensitive than true lemons; the fruit are thick-skinned and very large. It is likely a citron-lemon hybrid.

The Variegated Pink is a varietal of the eureka or lisbon cultivars with variegated patterns in the foliage and the rinds of immature green fruit. Upon maturing to yellow, the variegated pattern recedes in the fruit rind. The flesh and juice are pink or pinkish-orange instead of yellow.

The Verna is a Spanish variety of unknown origin.

The Yen Ben is an Australasian cultivar.

Culinary uses

Lemon Pickle

Lemon juice, rind, and zest are used in a wide variety of food and drink. Lemon juice is used to make lemonade, soft drinks, and cocktails. It is used in marinades for fish, where its acid neutralizes amines in fish by converting them into non-volatile ammonium salts, and meat, where the acid partially hydrolyzes tough collagen fibers, tenderizing the meat, but the low pH denatures the proteins, causing them to dry out when cooked. Lemon juice is frequently used in the United Kingdom to add to pancakes, especially on Shrove Tuesday.

Lemon juice is also used as a short-term preservative on certain foods that tend to oxidize and turn brown after being sliced, such as apples, bananas and avocados, where its acid denatures the enzymes that cause browning and degradation.

Lemon juice and rind are used to make marmalade and lemon liqueur. Lemon slices and lemon rind are used as a garnish for food and drinks. Lemon zest, the grated outer rind of the fruit, is used to add flavor to baked goods, puddings, rice and other dishes.

Preserved lemons are a part of Moroccan cuisine. They are also one of the main ingredients in many Indian cuisines. Either lemon pickle or mango pickle is part of everyday lunches in Southern India.^{[citation needed]}

The leaves of the lemon tree are used to make a tea and for preparing cooked meats and seafoods.

Other uses

Lemon oil may be used in aromatherapy. Researchers at The Ohio State University found that lemon oil aroma does not influence the human immune system, but may enhance mood. The low pH of juice makes it antibacterial.

Lemons were the primary commercial source of citric acid prior to the development of fermentation-based processes. A halved lemon is used as a finger moistener for those counting large amounts of bills, such as tellers and cashiers.

The juice of the lemon may be used for cleaning. A halved lemon dipped in salt or baking powder is used to brighten copper cookware. The acid dissolves the tarnish and the abrasives assist the cleaning. As a sanitary kitchen deodorizer the juice can deodorize, remove grease, bleach stains, and disinfect; when mixed with baking soda, it removes stains from plastic food storage containers. The oil of the lemon's peel also has various uses. It is used as a wood cleaner and polish, where its solvent property is employed to dissolve old wax, fingerprints, and grime. Lemon oil is also used as a nontoxic insecticide treatment. See orange oil.

One educational science experiment involves attaching electrodes to a lemon and using it as a battery to produce electricity. Although very low power, several lemon batteries can power a small digital watch. These experiments also work with other fruits and vegetables. Lemon juice is also sometimes used as an acid in educational science experiments.

In India, the lemon is used in Indian traditional medicines Siddha Medicine and Ayurveda.^{[citation needed]}

Lemon alternatives

Many plants taste or smell similar to lemons.

• Certain cultivars of basil
• Cymbopogon (Lemongrass)
• Lemon balm, a mint-like herbaceous perennial in the Lamiaceae family
• Two varieties of scented geranium: Pelargonium crispum (lemon geranium) and Pelargonium x melissinum 'Lemon Balm'
• Lemon myrtle, recently, this Australian bush food 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.
• Lemon thyme
• Lemon verbena
• Limes, another common sour citrus fruit, used similarly to lemons
• Certain cultivars of mint
• Magnolia grandiflora tree flowers

Production

India tops the production list with about 16% of the world's overall lemon and lime output, followed by Mexico (~14.5%), Argentina (~10%), Brazil (~8%) and Spain (~7%).

Top Ten Lemons and Limes Producers – 2007
Country	Production (Tonnes)
India	2,060,000F
Mexico	1,880,000F
Argentina	1,260,000F
Brazil	1,060,000F
Spain	880,000F
People's Republic of China	745,100F
United States	722,000
Turkey	706,652
Iran	615,000F
Italy	546,584
World	13,032,388F
No symbol = official figure, F = FAO estimate, A = Aggregate (may include official, semi-official or estimates); Source: Food And Agricultural Organization of United Nations: Economic And Social Department: The Statistical Division

Nutritional value

The average lemon contains approximately 3 tablespoons (50 mL) of juice. Lemons left unrefrigerated for long periods of time are susceptible to mold.

A bee on a Meyer lemon flower

Lemon, raw, without peel Nutritional value per 100 g (3.5 oz) Energy 121 kJ (29 kcal) Carbohydrates 9.32 g - Sugars 2.50 g - Dietary fiber 2.8 g Fat 0.30 g Protein 1.10 g Thiamine (vit. B1) 0.040 mg (3%) Riboflavin (vit. B2) 0.020 mg (2%) Niacin (vit. B3) 0.100 mg (1%) Pantothenic acid (B5) 0.190 mg (4%) Vitamin B6 0.080 mg (6%) Folate (vit. B9) 11 μg (3%) Vitamin C 53.0 mg (64%) Calcium 26 mg (3%) Iron 0.60 mg (5%) Magnesium 8 mg (2%) Phosphorus 16 mg (2%) Potassium 138 mg (3%) Zinc 0.06 mg (1%) Percentages are relative to US recommendations for adults. Source: USDA Nutrient Database