| Orange | |
|---|---|
| Orange blossoms and oranges on tree | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Rosids |
| Order: | Sapindales |
| Family: | Rutaceae |
| Genus: | Citrus |
| Species: | C. × sinensis |
| Binomial name | |
| Citrus × sinensis (L.) Osbeck[1] |
|
An orange—specifically, the sweet orange—is the citrus Citrus × sinensis (Citrus Sinensis (L.) Osbeck) and its fruit.[2] It is the most commonly grown tree fruit in the world.[3]
The orange is a hybrid of ancient cultivated origin, possibly between pomelo (Citrus maxima) and mandarin (Citrus reticulata).[4] It is an evergreen flowering tree generally growing to 9–10 m in height (although very old specimens have reached 15 m).[5] The leaves are arranged alternately, are ovate in shape with crenulate margins and are 4–10 cm long.[6] The orange fruit is a hesperidium, a type of berry.[7]
Orange trees are widely cultivated in tropical and subtropical climates for the delicious sweet fruit, which is peeled or cut (to avoid the bitter rind) and eaten whole, or processed to extract orange juice, and also for the fragrant peel.[8] In 2008, 68.5 million tons of oranges were grown worldwide, primarily in Brazil and the US states California[9] and Florida.[10]
Oranges probably originated in Southeast Asia[8] and were cultivated in China by 2500 BC. The fruit of Citrus sinensis is called sweet orange to distinguish it from Citrus aurantium, the bitter orange. The name is thought to derive ultimately from the Sanskrit[11] for the orange tree, with its final form developing after passing through numerous intermediate languages.
In a number of languages, it is known as a "Chinese apple", e.g., Dutch sinaasappel ("China's apple") or appelsien, or northern German Apfelsine.[12] In English, however, "Chinese apple" generally refers to the pomegranate.[13]
Contents |
All citrus trees are of the single genus, Citrus, and remain almost entirely interfertile; that is, there is only one "superspecies" which includes grapefruits, lemons, limes, oranges, and numerous other types and hybrids.[14]
Nevertheless, names have been given to the various members of the genus. The name "orange" applies primarily to the sweet orange, Citrus sinensis, which accounts for about 70% of world citrus production.[15] This article is limited to Citrus sinensis and its hybrids.
Other citrus species known as oranges include:
Taxonomy of the orange (and citrus in general) presents difficulties; the interfertility of citrus has resulted in numerous hybrids, bud unions, and cultivars; taxonomy is often controversial, confusing, or inconsistent.[4][15]
The fruit of a member of the genus Citrus is considered a hesperidium, a kind of modified berry, because it has numerous seeds, is fleshy and soft, derives from a single ovary, and is covered by a rind created by a leathery thickening of the ovary wall.[7][18] An orange seed is called a "pip".[19] The white thread-like material attached to the inside of the peel is called pith.[20]
Although the sweet orange will grow to different sizes and colours according to local conditions, it most commonly has ten carpels, or segments, inside. Unripe fruit is green. The pebbled exterior of ripe fruit can be bright orange to yellow-orange, but often retains a considerable amount of the green colour of unripe fruit.
Orange trees are generally grafted; the bottom part of the tree, including the roots and trunk, is called the rootstock, while the fruit-producing top part of the tree is called budwood (when talking about the process of grafting) or scion (when talking about the variety of orange).[21]
Citrus Sinensis (L.) Osbeck is broken down into four groups with distinct characteristics: Common oranges, blood oranges, navels, and acidless oranges.[22][23][24]
Common oranges (also called "white", "round" or "blond" oranges) make up about two-thirds of all oranges grown and include all oranges not described in one of the other three groups. They are used primarily for juice production.[22][24]
The Valencia or Murcia orange is one of the sweet oranges used for juice extraction. It is a late-season fruit, and therefore a popular variety when the navel oranges are out of season. For this reason, the orange was chosen to be the official mascot of the 1982 FIFA World Cup, which was held in Spain. The mascot was called "Naranjito" ("little orange"), and wore the colours of the Spanish football team uniform.
Thomas Rivers, an English nurseryman, imported this variety from the Azores Islands and catalogued it in 1865 under the name Excelsior. About 1870, he provided trees to S. B. Parsons, a Long Island nurseryman, who sold trees to E. H. Hart of Federal Point, Florida.[25]
The Hamlin orange was once the most important juice orange in Florida, replacing the inferior Parson Brown variety as the principal early-season juice orange. Today it is the predominant early-season orange grown in Florida and Brazil. It thrives in humid subtropical climates and is for that reason found primarily in Florida and Brazil; cooler, more arid climates (such as California) produce edible fruit, but the size is too small for commercial use.[5]
The cultivar was discovered in 1879 near Glenwood, Florida, in a grove later owned by A.G. Hamlin. It is small, smooth, not highly coloured, seedless and juicy, but the juice is pale. The fruit is of poor to medium quality but the tree is high-yielding and cold-tolerant. The fruit is harvested from October to December and this cultivar is now the leading early orange in Florida and possibly the world's principal variety of very early maturing common sweet orange.[5]
On pineland and hammock soil it is budded on sour orange which gives a high solids content. On sand, it does best on rough lemon rootstock.[3]
Navel oranges are characterized by the growth of a second fruit at the apex, which protrudes slightly and resembles a human navel. They are primarily used for eating, as the skin is thicker and easier to peel than a common orange, they are less juicy, and a bitterness from limonin during processing renders them less satisfactory for juice.[22] They are very popular because of their use as an eating orange, their widespread distribution, and their long growing season; in the United States, they are available from November through April, with peak supplies in January, February and March.[31]
According to Dorsett, Shamel, and Popenoe (1917) of the U.S. Department of Agriculture who conducted a study at first hand, a single mutation in 1810 to 1820 in a Selecta orange tree planted at a monastery near Bahia in Brazil, probably yielded the navel orange, also known as the Washington, Riverside, or Bahia navel.[32] However, a researcher at the University of California, Riverside, believes that the parent variety was more likely the Portuguese navel (Umbigo) orange described by Risso and Poiteau (1818–22).[32] The mutation causes the orange to develop a second orange at the base of the original fruit, opposite the stem, as a conjoined twin in a set of smaller segments embedded within the peel of the larger orange. From the outside, it looks similar to the human navel, hence its name.
Because the mutation left the fruit seedless, and therefore sterile, the only means available to cultivate more of this new variety is to graft cuttings onto other varieties of citrus tree. It was introduced into Australia in 1824 and Florida in 1835. Twelve such cuttings of the original tree were transplanted[33] to Riverside, California in 1870, which eventually led to worldwide popularity.[32] The California Citrus State Historic Park preserves this history in Riverside, California, as does the Orcutt Ranch Horticulture Center in Los Angeles County, California.
Today, navel oranges continue to be produced through cutting and grafting. This does not allow for the usual selective breeding methodologies, and so not only do the navel oranges of today have exactly the same genetic makeup as the original tree, and are therefore clones, all navel oranges can be considered to be the fruit of that single nearly two-hundred-year-old tree. The case is similar to that of the common yellow seedless banana, the Cavendish. On rare occasions, however, further mutations can lead to new varieties.[32]
Cara cara oranges (also called "red navel") are a type of navel orange grown primarily in Venezuela, South Africa, and California's San Joaquin Valley. The bright orange exterior of cara cara oranges is similar to other navels, but their interior is a distinctive pinkish red. They are sweet and comparatively low in acid.[34]
It is believed to have developed as a cross between the Washington navel and the Brazilian Bahia navel.[35] It was discovered at the Hacienda de Cara Cara in Valencia, Venezuela in 1976.[36]
From the major growing regions, South African cara caras are ready for market starting in August, Venezuelan fruits arrive in October and Californian fruits make their seasonal debut in late November.[34][35]
Blood oranges, which are very widely grown in Spain and Italy (as "sangüina" or "sanguigna", respectively) are characterized by dark red pigmentation. They are considered, in general, the most delicious juice orange.[22]
Blood oranges are a natural variety of C. sinensis derived from abnormal pigmentation of the fruit that gives its pulp a streaked red colour. The juice produced from such oranges is often dark burgundy, hence reminiscent of blood. Original blood oranges were first discovered and cultivated in the 15th century in Sicily; since then, however, their cultivation spread worldwide, and most blood oranges today are hybrids.
The fruit has found a niche as an interesting ingredient variation on traditional Seville marmalade, with its striking red streaks and distinct flavour. The scarlet navel is a variety with the same dual-fruit mutation as the navel orange.
Acidless oranges are an early-season fruit with very low levels of acid. They are also called "sweet" oranges in the US, with similar names in other countries: douce in France, sucrena in Spain, dolce (or maltese) in Italy, meski in North Africa and the Near East (where their peculiar rather bland taste is especially popular), lokkum in Turkey, succari in Egypt, and lima in Brazil.[22]
The lack of acid, which protects orange juice against spoilage in other groups, renders them generally unfit for processing, due to spoilage, so that they are primarily eaten rather than juiced. They remain profitable in areas of local consumption, but rapid spoilage renders them unsuitable for export to major population centers of Europe, Asia, or the United States.[22]
The sweet orange does not occur in the wild. It is believed to have been first cultivated in southern China, northeastern India, or perhaps southeastern Asia (formerly Indochina).[3]
The Persian orange, grown widely in southern Europe after its introduction to Italy in the 11th century, was bitter. It was used primarily for medicinal purposes.[3]
Italian traders might have introduced it to the Mediterranean area after 1450. Portuguese navigators have also been credited with bringing orange trees to the Mediterranean region around 1500.[3] After introduction of the sweet orange, it was quickly adopted as an edible fruit; it was so highly regarded that wealthy persons grew oranges in private conservatories, called orangeries. Certainly by 1646 it was well-known in Europe.[3]
In some South East Indo-European languages the orange was named after Portugal, which was formerly the main source of imports of sweet oranges. Examples are Bulgarian portokal портокал, Greek portokali πορτοκάλι, Persian portaghal پرتقال, Albanian portokall, Macedonian portokal портокал, and Romanian portocală. In Italian the word portogallo to refer to the orange fruit is dialectal.[37] It means literally "Portugal". Similar words are in common use in most Italian dialects across the whole country.[38] Related names can also be found in other languages: Turkish portakal, Arabic al-burtuqal البرتقال, Amharic birtukan, and Georgian p'ort'oxali ფორთოხალი.
Portuguese, Spanish, Arab, and Dutch sailors planted citrus trees along trade routes to prevent scurvy. On his second voyage in 1493, Christopher Columbus took the seeds of oranges, lemons and citrons to Haiti and the Caribbean. They were introduced in Florida (along with lemons) in 1513 by Spanish explorer Juan Ponce de León, to California by the Franciscans in the 18th century, and were introduced to Hawaii in 1792.
Spaniards undoubtedly introduced the sweet orange into South America and Mexico in the mid-1500s, and probably the French took it to Louisiana. It was from New Orleans that seeds were obtained and distributed in Florida about 1872 and many orange groves were established by grafting the sweet orange onto sour orange rootstocks. Arizona received the orange tree with the founding of missions between 1707 and 1710. The orange was brought to San Diego, California, by those who built the first mission there in 1769. An orchard was planted at the San Gabriel Mission around 1804. A commercial orchard was established in 1841 on a site that is now a part of Los Angeles. In 1781, a surgeon and naturalist on the ship Discovery collected orange seeds in South Africa, grew seedlings on board and presented them to tribal chiefs in the Hawaiian Islands on arrival in 1792. In time, the orange became commonly grown throughout Hawaii, but was virtually abandoned after the arrival of the Mediterranean fruit fly, and the fruit is now imported from the United States mainland.[3]
|
||||||||||||||||||||||||||||||||||||||||||
Like all citrus fruits, the orange is acidic: pH levels have been reported by reliable sources as low as 2.9[39] and as high as 4.0[39][40]
Grade numbers are determined by the amount of unsightly blemishes to the skin and firmness of the fruit (which do not affect consumer safety). The USDA separates blemishes into three categories:
Although not as juicy or delicious as the inside of an orange, the peel is edible, and has been consumed particularly in environments where there is scarcity of resources and where maximum nutritional value must be derived and minimal waste generated (for example, on a submarine.) The peel of an orange has increased vitamin C and fiber, however one should only consume the peels of organically grown and processed oranges, where chemical pesticides or herbicides would not have been used on the peel.[42]
Orange peel contains citral, an aldehyde that antagonizes the action of vitamin A. Therefore, anyone eating orange peels should make certain that their dietary intake of Vitamin A is sufficient.[43]
Two areas dominate orange growth and especially production of orange juice. The southeast coast of Brazil, surrounding São Paulo, produces more oranges than the next three countries combined. As almost 99% of the fruit from this region is processed for export, it is the overwhelming giant in worldwide orange juice production.
Mid-south Florida produces about half as many oranges as Brazil; however, the bulk of its orange juice is sold domestically. The Indian River area of Florida is known for the high quality of its juice, which is often sold fresh in the US. Because of the low yield and high quality of Indian River oranges, their juice is often blended with juice from other regions.[44]
Production of orange juice between these two makes up roughly 85% of the world market. Brazil exports 99% of its production, while 90% of Florida's production is consumed in the US.[45]
Orange juice is traded internationally in the form of frozen concentrated orange juice to reduce the volume used, so that storage and transportation costs are lower.[46]
| Top orange producers (million tons) |
2005 | 2008 |
| Brazil | 17.8 | 18.5 |
| United States | 8.4 | 9.1 |
| India | 3.1 | 4.4 |
| Mexico | 4.1 | 4.3 |
| China | 2.4 | 3.7 |
| Spain | 2.3 | 3.3 |
| Iran | 2.0 | 2.6 |
| Italy | 2.2 | 2.5 |
| Indonesia | 2.2 | 2.3 |
| Egypt | 1.8 | 2.1 |
| Pakistan | 1.6 | 1.7 |
| World Total | 61.7 | 68.5 |
| Source: UN Food & Agriculture Organisation (FAO)[47] |
||
Oranges grown for commercial production are grown in groves and are produced throughout the world. Brazil is by far the greatest producing area, followed by Florida, which accounts for 80% of the United States' crop.
|
||||||||||||||||||||
Brazil is the largest orange-producing nation in the world, and production is located primarily in the state of São Paulo, which accounts for approximately 80% of Brazil's production and 53% of total global FCOJ (frozen concentrated orange juice) production (in the region of Campinas, São Carlos, São José do Rio Preto and Barretos, and the western part of the state of Minas Gerais). In Brazil, the four major orange varieties of orange used for processing orange juice are the Hamlin, Pera Rio, Natal and Valencia.[48][49]
Propagation of orange trees is deceptively difficult, because hardy edible oranges are not generally grown from seed. Cultivars that produce good quality fruit are highly susceptible to root diseases. Grafted trees also begin bearing fruit many years earlier than trees reproduced by seed.[50]
Other benefits of grafting include more accurate reproduction of good fruit traits than plants derived from seed, and the opportunity to alter tree size, productivity, and other traits through rootstock influence, while maintaining identical fruit characteristics.[50]
Almost all orange trees are propagated in two stages. First, rootstock is grown from seed. When the seedling is well-established, the leafy top is cut off, and budwood from an existing tree is grafted onto the rootstock. It is the budwood that determines the variety of orange that is grown.
Sour orange, resistant to phytophthora parasitica (root rot or "foot rot"), was the preferred rootstock in Florida, especially in low hammock and flatwoods soils with high water table, until the discovery of the virus disease tristeza in Florida orange groves in 1952. Some were grown on sweet orange or rough lemon rootstock, but these are poor choices. Sweet orange is highly vulnerable to numerous pests and diseases, especially root rot, and lemon rootstock results in oranges that lack juice and sugar. Lemon rootstock, however, produces rapid growth and early fruiting. Sour rootstock is itself susceptible to a number of diseases, most notably the tristeza virus, which is carried by nematodes.
As citrus-growing stretched southward into high pineland, rough lemon (Citrus jambhiri) rootstock gained favour and was found to induce more rapid and vigorous growth and earlier bearing, counterbalancing its sensitivity to cold and tendency toward foot rot. Rough lemon became the dominant rootstock in Florida until it was found to be extremely susceptible to blight and was abandoned. Sour orange has been reinstated in recent years because tristeza has been more or less dormant since the 1940s and sour orange is now the prevailing stock for 50% of the orange trees in the state.[3]
Today, five types of rootstock predominate in (comparatively) cool climates where there is chance of cold, or especially freezing, weather (notably Florida and Southern Europe):
Oranges can be grown outdoors in warmer climates, and indoors in cooler climates. Like most citrus plants, oranges will not do well unless kept between 15.5 °C – 29 °C (60 °F – 85 °F). Orange trees grown from the seeds of a store-bought fruit may not produce fruit, and any fruit that is produced may be different than the parent fruit, due to modern techniques of hybridization. To grow the seed of a store-bought orange, one must not let the seed dry out (an approach used for many citrus plants). One method is to put the seeds between the halves of a damp paper towel until they germinate, and then plant them. Many just plant them straight into the soil, making sure to water them regularly. Oranges require a huge amount of water and the citrus industry in the Middle East is a contributing factor to the desiccation of the region.
Oranges are sensitive to frost, and a common treatment to prevent frost damage when sub-freezing temperatures are expected is to spray the trees with water, since as long as unfrozen water is turning to ice on the trees' branches, the ice that has formed stays just at the freezing point, giving protection even if air temperatures have dropped far lower.[58]
Another strategy to prevent freezing of orange crops and trees is burning fuel oil in smudge pots (also known as a choofa or orchard heater). These burn with a great deal of particulate emission. Condensation of water vapor on particulate soot prevents condensation on plants and raises air temperature very slightly. Smudge pots were first developed after a disastrous freeze in Southern California in January 1913 wiped out a whole crop.[59]
Canopy-shaking mechanical harvesters are increasingly being used in Florida to harvest process oranges. Current canopy shaker machines use a series of six- to seven-foot long tines to shake the tree canopy at a relatively constant shaking stroke and frequency.[60]
The first major pest attacking orange trees in the United States was the cottony cushion scale (Icerya purchasi), which was imported from Australia to California in 1868. Within 20 years, it had wiped out the citrus industry around Los Angeles and seriously limited orange growth throughout California.
In 1888, the USDA sent Alfred Koebele to Australia to study the scale in its native habitat. He brought back with him specimens of an Australian ladybird beetle, Novius cardinalis, and within a decade the scale had been controlled or eradicated throughout the state.[25]
As of 2010, the most serious threat to orange production is Citrus Greening Disease (Liberobacter asiaticum), an insect-vectored bacterium. Although common in parts of Asia, it was first reported in the Western Hemisphere in 2004 in Brazil, by Fundecitrus Brasil. (The insects that carry it were discovered in Florida in 1998.) Since then, it has attacked nearly 100% of the trees in Florida.[61] As of 2009, 87% of the trees in Brazil's primary orange growing areas (São Paulo and Minas Gerais) showed symptoms of greening, an increase of 50% over 2008.[62]
The disease is characterized by blotchy mottle on the leaves, and misshapen, poorly coloured, off-tasting fruit. In areas where the disease is endemic, citrus trees may live for only 5–8 years and never bear usable fruit.[61]
The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is an invasive insect pest of citrus in Brazil and Florida. It is an efficient vector of the bacterium, Liberobacter asiaticum, causal organism of citrus greening disease or "Huanglongbing" (HLB). The pest was first detected in Florida in 1998 and now occurs on all citrus throughout the state. HLB was first detected in Florida 2005 and is spreading rapidly. Generalist predators such as the ladybeetles, Curinus coeruleus, Olla v-nigrum, Harmonia axyridis, and Cycloneda sanguinea, and lacewings such as Ceraeochrysa spp. and Chrysoperla spp. make significant contribution to the mortality of ACP, resulting in 80–100% reduction in psyllid populations.
In contrast, parasitism by Tamarixia radiata, a species-specific parasitoid of ACP, is variable and generally low in southwest Florida, averaging less than 12% during May through September and 50% in November 2006.
Foliar applications of insecticides reduced psyllid populations for a short time at best, but also suppressed the populations of predatory ladybeetles. Soil application of aldicarb provided limited control of ACP while drenches of imidacloprid to young trees were effective for two months or more.[63]
Management of citrus greening disease is difficult and requires an integrated approach including use of clean stock, elimination of inoculum via voluntary and regulatory means, use of pesticides to control psyllid vectors in the citrus crop, and biological control of psyllid vectors in non-crop reservoirs. Nowhere in the world where citrus greening disease occurs is it under completely successful management.[61]
Greasy spot, caused by Mycosphaerella citri, produces leaf spots and defoliation of orange trees reducing tree vigor and yield. The fungus produces air-borne ascospores from pseudothecia in decomposing leaf litter on the grove floor.[64]
After harvesting, oranges have a shelf life of about one week at room temperature and one month refrigerated.[65] In either case, they are optimally stored loosely in an open or perforated plastic bag.[65] Oranges produce odours that are absorbed by meat, eggs and dairy products.[65]
Oranges cannot be artificially ripened and must be mature when harvested. (In Texas,[66] Arizona, California, and Florida, laws forbid harvesting immature fruit for human consumption.) Ripe oranges, however, often have some green or yellow-green colour in the skin. Ethylene gas is used to turn green skin orange. The process is called "degreening", or sometimes, "gassing", "sweating" or "curing". Its purpose is to remove the green colour from otherwise mature fruit.
Degreening is used primarily in the early fall when night temperatures have not been low enough for the peel to develop its characteristic mature colour. Late oranges such as Valencia sometimes regreen during the spring growth flush and may also be degreened.
Recommended degreening conditions include 82 to 85 °F temperature, 92 to 95% relative humidity and 1 to 5 ppm ethylene. Air circulation within the degreening room should produce about one change per minute. In addition, outside air ventilation should be adequate to maintain carbon dioxide level below one percent, which normally requires about one complete change of air per hour.
Degreening time varies with the amount of green colour, size of fruit and some cultural practices, e.g., excessive nitrogen fertilization promoting vigorous growth and oil-emulsion sprays after mid-July. Maximum degreening times in the US are 48 to 60 hours for oranges, but the degreening period should be as short as possible.[66]
The word orange is derived from Sanskrit नारङ्ग nāraṅgaḥ "orange tree."[67] The Sanskrit word is in turn borrowed from the Dravidian root for 'fragrant'. In Tamil, a bitter orange is known as நரண்டம் 'Narandam', a sweet orange is called நகருகம் 'nagarugam' and நாரி 'naari' means fragrance.[68] In Telugu the orange is called నరిఙ 'naringa'. The Sanskrit word was borrowed into European languages through Persian نارنگ nārang, Armenian նարինջ nārinj, Arabic نارنج nāranj, (Spanish-language naranja and Portuguese laranja), Late Latin arangia, Italian arancia or arancio, and Old French orenge, in chronological order. The first appearance in English dates from the 14th century. The forms starting with n- are older, and this initial n- may have been mistaken as part of the indefinite article, in languages with articles ending with an -n sound (e.g., in French une norenge may have been taken as une orenge), a process called juncture loss. The name of the colour is derived from the fruit, first appearing in this sense in 1542.
Some languages have different words for the bitter and the sweet orange, such as Modern Greek nerantzi and portokali, respectively. Or in Persian, the words are narang and porteghal (Portugal), in the same order. The reason is that the sweet orange was brought from China or India to Europe during the 15th century by the Portuguese. Some languages refer to it as Applesin (or variants), which means "Apple from China", while in Puerto Rico "jugo de china" refers to orange juice,[69] The bitter orange was introduced through Persia.
Several Slavic languages use the variants pomaranč (Slovak), pomeranč (Czech), pomaranča (Slovene), pomarańcza (Polish) from old French pomme d'orenge.[70]
The colour orange is named after the appearance of a ripe orange.[71]
Oranges are widely grown in warm climates worldwide, and the flavours of oranges vary from sweet to sour. The fruit is commonly peeled and eaten fresh, or squeezed for its juice. It has a thick bitter rind that is usually discarded, but can be processed into animal feed by removal of water, using pressure and heat. It is also used in certain recipes as flavouring or a garnish. The outer-most layer of the rind can be grated or thinly veneered with a tool called a zester, to produce orange zest. Zest is popular in cooking because it contains the oil glands and has a strong flavour similar to the fleshy inner part of the orange. The white part of the rind, called the pericarp or albedo and including the pith, is a source of pectin and has nearly the same amount of vitamin C as the flesh.
However, d-Limonene is classified from slightly toxic to humans[73] to very toxic to marine life[74] in different countries. Its smell is considered more pleasant by some than those of other cleaning agents.
Although once thought to cause renal cancer in rats, limonene now is known as a chemopreventive agent[75] with potential value as a dietary anti-cancer tool in humans.[76] There is no evidence for carcinogenicity or genotoxicity in humans. The Carcinogenic Potency Project estimates that it causes human cancer on a level roughly equivalent to that caused by exposure to caffeic acid via dietary coffee intake.[77] The IARC classifies d-limonene under Class 3: not classifiable as to its carcinogenicity to humans.[78]
|
|||||||||||||||||