Oranges

The orange, also called sweet orange to distinguish it from the bitter orange (''Citrus × aurantium''), is the fruit of a tree in the family Rutaceae. Botanically, this is the hybrid ''Citrus'' × ''sinensis'', between the pomelo (''Citrus maxima'') and the mandarin orange (''Citrus reticulata''). The chloroplast genome, and therefore the maternal line, is that of pomelo. There are many related hybrids including of mandarins and sweet orange. The sweet orange has had its full genome sequenced.

The orange originated in a region encompassing Southern China, Northeast India, and Myanmar; the earliest mention of the sweet orange was in Chinese literature in 314 BC. Orange trees are widely grown in tropical and subtropical areas for their sweet fruit. The fruit of the orange tree can be eaten fresh or processed for its juice or fragrant peel. In 2022, 76 million tonnes of oranges were grown worldwide, with Brazil producing 22% of the total, followed by India and China.

Oranges, variously understood, have featured in human culture since ancient times. They first appear in Western art in the ''Arnolfini Portrait'' by Jan van Eyck, but they had been depicted in Chinese art centuries earlier, as in Zhao Lingrang's Song dynasty fan painting ''Yellow Oranges and Green Tangerines''. By the 17th century, an orangery had become an item of prestige in Europe, as seen at the Versailles Orangerie. More recently, artists such as Vincent van Gogh, John Sloan, and Henri Matisse included oranges in their paintings.

Description

The orange tree is a relatively small evergreen, flowering tree, with an average height of , although some very old specimens can reach . Its oval leaves, which are alternately arranged, are long and have crenulate margins. Sweet oranges grow in a range of different sizes, and shapes varying from spherical to oblong. Inside and attached to the rind is a porous white tissue, the white, bitter mesocarp or albedo (''pith''). The orange contains a number of distinct ''carpels'' (segments or pigs, botanically the fruits) inside, typically about ten, each delimited by a membrane and containing many juice-filled vesicles and usually a few pips. When unripe, the fruit is green. The grainy irregular rind of the ripe fruit can range from bright orange to yellow-orange, but frequently retains green patches or, under warm climate conditions, remains entirely green. Like all other citrus fruits, the sweet orange is non- climacteric, not ripening off the tree. The ''Citrus sinensis'' group is subdivided into four classes with distinct characteristics: common oranges, blood or pigmented oranges, navel oranges, and acidless oranges. The fruit is a hesperidium, a modified berry; it is covered by a rind formed by a rugged thickening of the ovary wall.Bailey, H. and Bailey, E. (1976). ''Hortus Third''. Cornell University MacMillan. N.Y. p. 275.

File:Orange Blossom.JPG, Flowers
File:Orange tree fruiting.jpg, Fruit starting to develop
File:OrangeBloss wb.jpg, Flowers and fruit simultaneously
File:Laranxeira Naranjo GFDL.JPG, Mature tree in Galicia, Spain, fruiting in November
File:Structure of an orange.svg, Structure of the botanical hesperidium

History

Hybrid origins

''Citrus'' trees are angiosperms, and most species are almost entirely interfertile. This includes grapefruits, lemons, limes, oranges, and many citrus hybrids. As the interfertility of oranges and other citrus has produced numerous hybrids and cultivars, and bud mutations have also been selected, citrus taxonomy has proven difficult.

The sweet orange, '' Citrus x sinensis'', is not a wild fruit, but arose in domestication in East Asia. It originated in a region encompassing Southern China, Northeast India, and Myanmar.
The fruit was created as a cross between a non-pure mandarin orange and a hybrid pomelo that had a substantial mandarin component. Since its chloroplast DNA is that of pomelo, it was likely the hybrid pomelo, perhaps a pomelo BC1 backcross, that was the maternal parent of the first orange. Based on genomic analysis, the relative proportions of the ancestral species in the sweet orange are approximately 42% pomelo and 58% mandarin. and Supplement All varieties of the sweet orange descend from this prototype cross, differing only by mutations selected for during agricultural propagation. Sweet oranges have a distinct origin from the bitter orange, which arose independently, perhaps in the wild, from a cross between pure mandarin and pomelo parents.

Sweet oranges have in turn given rise to many further hybrids including the grapefruit, which arose from a sweet orange x pomelo backcross. Spontaneous and engineered backcrosses between the sweet orange and mandarin oranges or tangerines have produced the clementine and murcott. The ambersweet is a complex sweet orange x (Orlando tangelo x clementine) hybrid. The citranges are a group of sweet orange x trifoliate orange (''Citrus trifoliata'') hybrids.

Arab Agricultural Revolution

In Europe, the Moors introduced citrus fruits including the bitter orange, lemon, and lime to Al-Andalus in the Iberian Peninsula during the Arab Agricultural Revolution. Large-scale cultivation started in the 10th century, as evidenced by complex irrigation techniques specifically adapted to support orange orchards. Citrus fruits—among them the bitter orange—were introduced to Sicily in the 9th century during the period of the Emirate of Sicily, but the sweet orange was unknown there until the late 15th century or the beginnings of the 16th century, when Italian and Portuguese merchants brought orange trees into the Mediterranean area.

Spread across Europe

Shortly afterward, the sweet orange quickly was adopted as an edible fruit. It was considered a luxury food grown by wealthy people in private conservatories, called orangeries. By 1646, the sweet orange was well known throughout Europe; it went on to become the most often cultivated of all fruit trees. Louis XIV of France had a great love of orange trees and built the grandest of all royal Orangeries at the Palace of Versailles. At Versailles, potted orange trees in solid silver tubs were placed throughout the rooms of the palace, while the Orangerie allowed year-round cultivation of the fruit to supply the court. When Louis condemned his finance minister, Nicolas Fouquet, in 1664, part of the treasures that he confiscated were over 1,000 orange trees from Fouquet's estate at Vaux-le-Vicomte.

To the Americas

Spanish travelers introduced the sweet orange to the American continent. On his second voyage in 1493, Christopher Columbus may have planted the fruit on Hispaniola. Subsequent expeditions in the mid-1500s brought sweet oranges to South America and Mexico, and to Florida in 1565, when Pedro Menéndez de Avilés founded St Augustine. Spanish missionaries brought orange trees to Arizona between 1707 and 1710, while the Franciscans did the same in San Diego, California, in 1769. Archibald Menzies, the botanist on the Vancouver Expedition, collected orange seeds in South Africa, raised the seedlings on board, and gave them to several Hawaiian chiefs in 1792. The sweet orange came to be grown across the Hawaiian Islands, but its cultivation stopped after the arrival of the Mediterranean fruit fly in the early 1900s. Florida farmers obtained seeds from New Orleans around 1872, after which orange groves were established by grafting the sweet orange on to sour orange rootstocks.

California

Citrus cultivation in California began with the Spanish missionaries, who planted oranges and lemons at Baja California around 1739 and at Alta California missions by 1769. Early fruit was thick-skinned and sour, not suited for commercial markets. The first sizable grove was established at Mission San Gabriel in 1804, with about 400 trees on six acres. This mission-based agriculture ended with secularization which closed the missions and gave away their lands in 1835. Jean-Louis Vignes likely planted the first private orange grove in Los Angeles in 1834. William Wolfskill planted his orchard in Los Angeles in 1841. By 1862, his orchards held two-thirds of the state's orange trees. The California gold rush (from 1849) increased demand for oranges, especially for their vitamin C, which helped prevent scurvy among miners. This spurred gradual expansion of orchards. In the early 1870s, Wolfskill’s reported profits of $1,000 per acre attracted Midwestern farmers to citrus growing, especially in Orange County.

The 1870s saw the introduction of improved fruit varieties. In 1873, navel orange plants from Brazil were distributed by the U.S. Department of Agriculture. Luther C. Tibbets and Eliza Tibbets successfully cultivated these in Riverside, leading to widespread planting of the sweet, seedless navel orange, which became the backbone of the California citrus industry. The Valencia orange, introduced in 1876, matured in summer and fall, complementing the winter-ripening navel and providing oranges year-round. The completion of major railroads (Southern Pacific in 1877, and the Santa Fe in 1885) and the introduction of ventilated boxcars revolutionized distribution, opening national markets and triggering a planting frenzy in southern California. By 1885, the number of citrus trees in California had grown from 90,000 (in 1875) to 2 million, and to 4.5 million by 1901.

The 1890s brought pest control advances (spraying, fumigation) and frost protection (heaters, later wind machines). The University of California established its Citrus Experiment Station in 1907, supporting research and innovation. Cooperative marketing emerged with the formation of the California Fruit Growers Exchange in 1905, later known as Sunkist Growers Inc., which helped standardize and market California citrus worldwide. By the 1980s, California was the second largest orange producer in the U.S., after Florida.

Etymology

The word "orange" derives from Sanskrit (), meaning 'orange tree'. The Sanskrit word reached European languages through Persian () and its Arabic derivative (). The word entered Late Middle English in the 14th century via Old French . Other forms include Old Provençal , Italian ''arancia'', formerly ''narancia''. In several languages, the initial ''n'' present in earlier forms of the word dropped off because it may have been mistaken as part of an indefinite article ending in an ''n'' sound. In French, for example, may have been heard as . This linguistic change is called juncture loss. orange (color), The color was named after the fruit, with the first recorded use of ''orange'' as a color name in English in 1512.

Composition

Nutrition

Orange flesh is 87% water, 12% carbohydrates, 1% protein, and contains negligible fat (see table). As a 100-gram reference amount, orange flesh provides 47 calories, and is a rich source of vitamin C, providing 64% of the Daily Value. No other micronutrients are present in significant amounts (see table).

Phytochemicals

Oranges contain diverse phytochemicals, including carotenoids ( beta-carotene, lutein