The lemon is the common name for Citrus limon. The reproductive tissue surrounds the seed of the angiosperm lemon tree. The lemon is used for culinary and nonculinary purposes throughout the world. The fruit is used primarily for its juice, though the pulp and rind (zest) are also used, primarily in cooking and baking. Lemon juice is about 5% (approximately 0.3 mole per liter) citric acid, which gives lemons a tart taste, and a pH of 2 to 3. This makes lemon juice an inexpensive, readily available acid for use in educational science experiments. Lemons are also known for their sourness. Because of the tart flavor, many lemon-flavored drinks and candies are available on the market, including lemonade.
The exact origin of the lemon has remained a mystery, though it is widely presumed that lemons first grew in India, northern Burma, and China.  In South and South East Asia, it was known for its antiseptic properties and it was used as an antidote for various poisons. It was later introduced to Persia and then to Iraq and Egypt around AD 700. The lemon was first recorded in literature in a tenth 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 AD 1000 and AD 1150.
Lemons entered Europe (near southern Italy) no later than the first century AD, during the time of Ancient Rome. However, they were not widely cultivated. The first real lemon cultivation in Europe began in Genoa in the middle of the fifteenth century. It was later introduced to the Americas in 1493 when Christopher Columbus brought lemon seeds to Hispaniola along his voyages. Spanish conquest throughout the New World helped spread lemon seeds. It was mainly used as ornament and medicine. In 1700s and late 1800s, lemons were increasingly planted in Florida and California when lemons began to be used in cooking and flavoring.
The Meyer lemon, actually a cross between a lemon and possibly an orange or a mandarin, was named for 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.
Lemons are used to make lemonade, and as a garnish for drinks. Many mixed drinks, soft drinks, iced tea, and water are often served with a wedge or slice of lemon in the glass or on the rim. The average lemon contains approximately 3 tablespoons of juice. Allowing lemons to come to room temperature before squeezing (or heating briefly in a microwave) makes the juice easier to extract. Lemons left unrefrigerated for long periods of time are susceptible to mold.
Lemon juice, alone or in combination with other ingredients, is used to marinate meat before cooking: the acid provided by the juice partially hydrolyzes the tough collagen fibers in the meat (tenderizing the meat), though the juice does not have any antibiotic effects.
Lemons, alone or with oranges, are used to make marmalade. The grated rind of the lemon, called lemon zest, is used to add flavor to baked goods, puddings, rice and other dishes. Pickled lemons are a Moroccan delicacy. A liqueur called limoncello is made from lemon rind.
When lemon juice is sprinkled on certain foods that tend to oxidize and turn brown after being sliced, such as apples, bananas and avocados, the acid acts as a short-term preservative by denaturing the enzymes that cause browning and degradation.
Several other plants have a similar taste 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. Limes are often used instead of lemons.
Many other plants are noted to 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.
India tops the production list with ~16% of the world's overall lemon and lime output followed by Mexico(~14.5%), Argentina(~10%), Brazil(~8%) and Spain(~7%).
|colspan=3||Top Ten Lemons and Limes Producers — 2007|
|colspan=5 style="font-size:.7em"||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 Devision