| Papaya | |
|---|---|
| Papaya tree and fruit, from Koehler's Medicinal-Plants (1887) | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Rosids |
| Order: | Brassicales |
| Family: | Caricaceae |
| Genus: | Carica |
| Species: | C. papaya |
| Binomial name | |
| Carica papaya L. |
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The papaya (from Carib via Spanish), papaw, or pawpaw is the fruit of the plant Carica papaya, the sole species in the genus Carica of the plant family Caricaceae. It is native to the tropics of the Americas, and was first cultivated in Mexico[1] several centuries before the emergence of the Mesoamerican classical civilizations.
The papaya is a large tree-like plant, with a single stem growing from 5 to 10 metres (16 to 33 ft) tall, with spirally arranged leaves confined to the top of the trunk. The lower trunk is conspicuously scarred where leaves and fruit were borne. The leaves are large, 50–70 centimetres (20–28 in) diameter, deeply palmately lobed with 7 lobes. The tree is usually unbranched, unless lopped. The flowers are similar in shape to the flowers of the Plumeria, but are much smaller and wax-like. They appear on the axils of the leaves, maturing into the large 15–45 centimetres (5.9–18 in) long, 10–30 centimetres (3.9–12 in) diameter fruit. The fruit is ripe when it feels soft (as soft as a ripe avocado or a bit softer) and its skin has attained an amber to orange hue.
Carica papaya was the first fruit tree to have its genome deciphered.[2]
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Carica papaya plants, and their fruits, are generally known as papayas. The papaya is also commonly called pawpaw or papaw,[3][4] although in North America the term pawpaw usually refers to plants in the unrelated North American genus Asimina, especially A. triloba, which produces large, edible fruits. The papaya is also sometimes called mugua, a name used in traditional Chinese medicine for Chaenomeles speciosa (flowering quince) or Pseudocydonia sinensis (Chinese quince).[5] In the Dominican Republic, the papaya is usually called "lechosa", a name associated with the plant's milky sap.
Originally from southern Mexico (particularly Chiapas and Veracruz), Central America, and northern South America, the papaya is now cultivated in most tropical countries. In cultivation, it grows rapidly, fruiting within 3 years. It is, however, highly frost sensitive, limiting papaya production to tropical lands.
Papayas are susceptible to the papaya ringspot virus, which causes premature molting and malformation of the leaves.[6] In the 1990s, the papaya ringspot virus threatened to wipe out Hawaii's papaya industry completely. Genetically altered plants that have some of the virus's DNA incorporated into the DNA of the plant are resistant to the virus.[6] Cultivars that had been genetically modified to be resistant to the virus (including 'SunUp' and 'Rainbow'), were then introduced there.[7] Phillipine researchers have recently developed conventionally bred, non-genetically engineered papaya that are proving resistant to the papaya ringspot virus.[8] In 2004, it was found that papayas throughout Hawaii had experienced hybridization with the genetically modified varieties and that many seed stocks were contaminated.[9] By 2010, 80% of Hawaiian papaya plants were genetically modified.
The papaya is also susceptible to the fruit fly, a small wasp-like insect that lays its eggs in young fruit.
Two kinds of papayas are commonly grown. One has sweet, red (or orangish) flesh, and the other has yellow flesh; in Australia these are called "red papaya" and "yellow papaw", respectively.[10] Either kind, picked green, is called a "green papaya."
The large-fruited, red-fleshed 'Maradol', 'Sunrise', and 'Caribbean Red' papayas often sold in U.S. markets are commonly grown in Mexico and Belize.[11]
'SunUp' and 'Rainbow' are genetically modified cultivars developed in Hawaii that are resistant to the papaya ringspot virus.[6][12]
Papayas can be used as a food, a cooking aid, and in traditional medicine. The stem and bark may be used in rope production.
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 163 kJ (39 kcal) |
| Carbohydrates | 9.81 g |
| - Sugars | 5.90 g |
| - Dietary fibre | 1.8 g |
| Fat | 0.14 g |
| Protein | 0.61 g |
| Vitamin A equiv. | 328 μg (41%) |
| Thiamine (vit. B1) | 0.04 mg (3%) |
| Riboflavin (vit. B2) | 0.05 mg (4%) |
| Niacin (vit. B3) | 0.338 mg (2%) |
| Vitamin B6 | 0.1 mg (8%) |
| Folate (vit. B9) | 38 μg (10%) |
| Vitamin C | 61.8 mg (74%) |
| Calcium | 24 mg (2%) |
| Iron | 0.10 mg (1%) |
| Magnesium | 10 mg (3%) |
| Phosphorus | 5 mg (1%) |
| Potassium | 257 mg (5%) |
| Sodium | 3 mg (0%) |
| Percentages are relative to US recommendations for adults. |
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Papaya fruit is a rich source of nutrients such as provitamin A carotenoids, vitamin C, B vitamins, dietary minerals and dietary fiber. Papaya skin, pulp and seeds also contain a variety of phytochemicals, including polyphenols.
The ripe fruit of the papaya is usually eaten raw, with or without skin or seeds.
The unripe green fruit can be eaten cooked, usually in curries, salads, and stews. Green papaya is used in Southeast Asian cooking, both raw and cooked.[13] In Thai cuisine, papaya is used to make som tam when still not fully ripe. In Indonesian cuisine, the unripe green fruits and young leaves are boiled for use as part of lalab salad, while the flower buds are sautéed and stir fried with chillies and green tomatoes as Minahasan papaya flower vegetable dish. Papayas have a relatively high amount of pectin, which can be used to make jellies. The smell of ripe, fresh papaya flesh can strike some people as unpleasant.
The black seeds of the papaya are edible and have a sharp, spicy taste. They are sometimes ground and used as a substitute for black pepper.
In some parts of Asia, the young leaves of the papaya are steamed and eaten like spinach.
In some parts of the world, papaya leaves are made into tea as a treatment for malaria.[14] Anti-malarial and anti-plasmodial activity has been noted in some preparations of the plant,[14] but the mechanism is not understood and no treatment method based on these results has been scientifically proven.[14]
Both green papaya fruit and the tree's latex are rich in papain, a protease used for tenderizing meat and other proteins. Its ability to break down tough meat fibers was used for thousands of years by indigenous Americans. It is now included as a component in powdered meat tenderizers.
Papaya is marketed in tablet form to remedy digestive problems.
Papain is also applied topically (in countries where it grows) for the treatment of cuts, rashes, stings and burns. Papain ointment is commonly made from fermented papaya flesh, and is applied as a gel-like paste. Harrison Ford was treated for a ruptured disc incurred during filming of Indiana Jones and the Temple of Doom by papain injections.[15]
Women in India, Bangladesh, Pakistan, Sri Lanka, and other countries have long used green papaya as a folk remedy for contraception and abortion. Enslaved women in the West Indies were noted for consuming papaya to prevent pregnancies and thus preventing their children from being born into slavery.[16]
Preliminary medical research in animals has confirmed the potential contraceptive and abortifacient capability of papaya, and also found that papaya seeds have contraceptive effects in adult male langur monkeys, and possibly in adult male humans.[17] Unripe papaya is especially effective in large amounts or high doses. Ripe papaya is not teratogenic and will not cause miscarriage in small amounts. Phytochemicals in papaya may suppress the effects of progesterone.[18]
Papaya is frequently used as a hair conditioner, but should be used in small amounts. Papaya releases a latex fluid when not quite ripe, which can cause irritation and provoke allergic reaction in some people. The papaya fruit, seeds, latex, and leaves also contains carpaine, an anthelmintic alkaloid (a drug that removes parasitic worms from the body), which can be dangerous in high doses.
It is speculated that the latex concentration of unripe papayas may cause uterine contractions, which may lead to a miscarriage. Papaya seed extracts in large doses have a contraceptive effect on rats and monkeys, but in small doses have no effect on the unborn animals.
Excessive consumption of papaya can cause carotenemia, the yellowing of soles and palms, which is otherwise harmless. However, a very large dose would need to be consumed; papaya contains about 6% of the level of beta carotene found in carrots (the most common cause of carotenemia).[19]
The paw paw appears in the lyrics of the song "The Bare Necessities" from Disney's animated film, The Jungle Book (1967). Baloo, the bear, sings the song and contrasts the smooth fruit of the "big paw paw" with the spiny, prickly pear. Given the jungle setting, this refers to the Carica papaya, rather than the pawpaw native to North America, Asimina triloba.