sPOTLIGHT iNGREDIENT: lEMON
Lemon (Citrus × limon) is a hybrid of the plant genus Citrus, as well as the common name for the popular edible fruit of this small tree or spreading bush. The lemon plant is characterized by thorny branches and white flowers with purple edges, while the acidic, juicy fruit is oval (egg-shaped), has an aromatic rind that is typically yellow when ripe (green as immature or under certain environmental conditions), and has a prominent nipple or bulge on the blossom end.
The Citrus genus is a group of flowering plants in the family Rutaceae (orange family) that originated in tropical and subtropical southeast Asia and that have a distinctive berry with the internal parts divided into segments. Other members of the Citrus genus include oranges, limes, citrons, grapefruit, pomelos (pummelo, pommelo), and mandarins (tangerines). Most members of the Citrus genus arose as hybrids, and the hybridized types of citrus, such as lemon (Citrus limon), may or may not be recognized as species according to different taxonomies (Krueger 2003).
While the fruit of the lemon serves the plant's individual purpose of reproduction, it also serves a wider value for humans in terms of culinary and non-culinary uses. Among the culinary uses are the use of the juice in drinks, garnishes for drinks, condiments, salad dressings, and squeezed over cooked meat or vegetables. As an astringent citrus, lemons generally are not eaten on their own. Among non-culinary purposes are the use of lemon oil in perfumes, cosmetics, and furniture polish and the tree for aesthetic purposes.
Lemon juice is about five percent acid, which gives lemons a sour taste and a pH of 2 to 3. This makes lemon juice a cheap, readily available acid for use in educational science experiments.
A lemon tree can grow up to ten 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 (Lanzara and Pizetti 1978).
Lemon fruit are oval and can range from about the size of a large egg to a small grapefruit (Herbst 2001). When ripe, they have a bright yellow nose, a layer of pith underneath and a paler yellow segmented interior. Small seeds commonly known as 'floopies' are found within the fruit; the skin can be thick or thin. Notably, the color of citrus fruits only develops in climates with a (diurnal) cool winter. In tropical regions with no winter, citrus fruits remain green until maturity. Commercially, lemons are commonly picked while green and ripened in cool, dark rooms.
For cooler winter areas, lemon and lime trees should not be grown, since they are more sensitive to winter cold than other citrus fruits. The largest producers are Italy and the United States. In the United States, lemons are commercially grown in cooler-summer/moderate-winter coastal Southern California, because sweetness is neither attained nor expected in retail lemon fruit. Other top producing nations include Spain, Greece, and Argentina.
Krueger (2003) claims that the generally accepted view is that there were three primordial Citrus species—Citrus medica (citrons), Citrus maxima (pumelos), and Citrus reticulata (mandarins)—and that all other types of citrus rose from single or sequential hybridization events between these species or their offspring. Based on whether the hybridized types of citrus are recognized as species, anywhere from three to 170 species are recognized, with the commonly used system of Swingle recognizing 16 species (Krueger 2003).
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. The use and cultivation of the lemon, by the Cantonese (Southern Barbarians) is noted in the early twelfth century. 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 literature of 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 [pronounced with long e and short u]), akin to the Sanskrit nimbuka. They were cultivated in Genoa, Italy in the mid-fiteenth century, and appeared in the Azores in 1494. Research has identified lemons in the ruins of Pompeii (Russell and Cutler 2004). Lemons were once used by the British Royal Navy to combat scurvy, as they provided a large amount of Vitamin C.
- Danielle Lasit