Carica papaya

This article is about Carica papaya, the widely cultivated papaya (or papaw or pawpaw), a tropical fruit tree; "Papaya" redirects here. For the mountain papaya of South America, see Vasconcellea pubescens. For the Eastern North American tree (and fruit) called "pawpaw", see Asimina triloba. For other uses of "papaya", see Papaya (disambiguation).

Not to be confused with Chaenomeles speciosa (flowering quince) or Pseudocydonia chinensis (Chinese quince), which like Carica papaya are sometimes called mugua.

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.

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 several centuries before the emergence of the Mesoamerican classic cultures.

The papaya is a large tree-like plant, with a single stem growing from 5 to 10 metres (16 to 33 ft) tall^[1], 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 (like 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]

Common names

Carica papaya plants, and their fruits, are generally known as papayas. However, 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).^{[citation needed][5]} In the Dominican Republic, the papaya is usually called "lechoza", a name associated with the plant's milky sap.

Cultivation

A papaya seedling.

Papaya output in 2005, shown as a percentage of the top producer, Brazil (1,700,000 tonnes)

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.

Pests and diseases

Main article: List of papaya diseases

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.^{[citation needed]}

The papaya is also susceptible to the fruit fly, a small wasp-like insect that lays its eggs in young fruit.

Cultivars

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]

Uses

Papayas can be used as a food, a cooking aid, and in medicine. The stem and bark are also used in rope production.

Nutrition

Papaya fruit is a rich source of antioxidants nutrients such as carotenes, vitamin C and flavonoids; the B vitamins, folate and pantothenic acid; and the minerals, potassium and magnesium; and fiber. Together, these nutrients promote the health of the cardiovascular system and also provide protection against colon cancer. Papayas may be very helpful for the prevention of atherosclerosis and diabetic heart disease.^[13]

Gastronomy

Papaya, raw

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.

The ripe fruit of the papaya is usually eaten raw, 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.^[14] In Thailand, papaya is used to make som tam when still not fully ripe. 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 papaya are steamed and eaten like spinach. In some parts of the world, papaya leaves are made into tea as a preventative for malaria, although there is no scientific evidence for the effectiveness of this treatment.^[15]

Meat tenderizing

Green papaya fruit and the tree's latex are both rich in an enzyme called papain, a protease which is useful in 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.

Folk medicine

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.^[16]

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.^[17] Medical research in animals has confirmed the 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, as well.^[18] 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.^[19]

Allergies and side effects

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).^[20]

Medicinal potential

Papaya. Moche Culture. Larco Museum Collection. The Moche often depicted papayas in their ceramics.^[21]

• The juice has an in vitro antiproliferative effect on liver cancer cells, probably due to its component of lycopene^[22] or immune system stimulation.^[23]
• Papaya seed could be used as an antibacterial agent for Escherichia coli, Staphylococcus aureus or Salmonella typhi, although further research is needed before advocating large-scale therapy.^[24]
• Papaya seed extract may be nephroprotective (protect the kidneys) in toxicity-induced kidney failure.^[25]

Cultural significance

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 paw paw native to North America, Asimina triloba.

See also

• Asimina triloba, pawpaw (of North America)
• Chaenomeles speciosa, flowering quince, which, like Carica papaya, is sometimes called mugua
• Pseudocydonia, Chinese quince, also sometimes called mugua

Notes and references

1. ^ 30 feet Tall Papaya Tree in Pasalapudi Village of Vundrajavaram Mandal in West Godavari district
2. ^ Comment on transgenic 'SunUp' papaya genome sequencing on Nature magazine
3. ^ Merriam-Webster Online: pawpaw
4. ^ Delbridge, A., and J. R. L. Bernard. 1988 The Macquarie Concise Dictionary. The Macquarie Library: Sydney.
5. ^ Subhuti Dharmananda 2005. "Chaenomeles: A relaxing and strengthening fruit" in Institute for Traditional Medicine database ITMonline.org
6. ^ ^{a b c} http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_03.html
7. ^ Hawaiipapaya.com
8. ^ http://www.springerlink.com/content/48t805l7w7564288
9. ^ Hawaii Reports Widespread Contamination of Papaya Crop by GE Varieties, grain.org
10. ^ "Papaya Vs Papaw". News (15 April 2005). Horticulture Australia. http://www.horticulture.com.au/news_events/news.asp?id=34. Retrieved 22 July 2011. 
11. ^ Sagon, Candy. "Maradol Papaya". Market Watch (13 Oct 2004). The Washington Post. http://www.washingtonpost.com/wp-dyn/articles/A26970-2004Oct12.html. Retrieved 21 July 2011. 
12. ^ http://www.harc-hspa.com/publications/TF5.pdf
13. ^ http://www.whfoods.com/genpage.php?tname=foodspice&dbid=47
14. ^ Green Papaya Salad Recipe - ThaiTable.com
15. ^ [1]^{[dead link]}
16. ^ Entry on Harrison Ford's back treatment.
17. ^ Morton, J.F. (1987). Papaya. In: Fruits of warm climates.. pp. 336–346. http://www.hort.purdue.edu/newcrop/morton/papaya_ars.html#Folk%20Uses. 
18. ^ Lohiya, N. K.; B. Manivannan, P. K. Mishra, N. Pathak, S. Sriram, S. S. Bhande, and S. Panneerdoss (March 2002). "Chloroform extract of Carica papaya seeds induces long-term reversible azoospermia in langur monkey" (– ^{Scholar search}). Asian Journal of Andrology 4 (1): 17–26. PMID 11907624. Archived from the original on October 18, 2006. http://web.archive.org/web/20061018094908/http://www.asiaandro.com/1008-682X/4/17.htm. Retrieved 2006-11-18. ^{[dead link]}
19. ^ Oderinde, O; Noronha, C; Oremosu, A; Kusemiju, T; Okanlawon, OA (2002). "Abortifacient properties of Carica papaya (Linn) seeds in female Sprague-Dawley rats". Niger Postgrad Medical Journal 9 (2): 95–8. PMID 12163882. 
20. ^ "Search the USDA National Nutrient Database for Standard Reference". Nal.usda.gov. http://www.nal.usda.gov/fnic/foodcomp/search/. Retrieved 2010-08-18. 
21. ^ Berrin, Katherine & Larco Museum. The Spirit of Ancient Peru:Treasures from the Museo Arqueológico Rafael Larco Herrera. New York: Thames and Hudson, 1997.
22. ^ Rahmat, Asmah et al.. "Antiproliferative activity of pure lycopene compared to both extracted lycopene and juices from watermelon (Citrullus vulgaris) and papaya (Carica papaya) on human breast and liver cancer cell lines". http://www.scialert.net/pdfs/jms/2002/55-58.pdf. Retrieved 9 May 2009. 
23. ^ "Papaya extract thwarts growth of cancer cells in lab tests". http://www.sciencedaily.com/releases/2010/03/100309182449.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29. Retrieved 3 March 2010. 
24. ^ "The invitro assessment of antibacterial effect of papaya seed extract against bacterial pathogens isolated from urine, wound and stool.". http://www.unboundmedicine.com/medline/ebm/record/18711992/full_citation/The_invitro_assessment_of_antibacterial_effect_of_papaya_seed_extract_against_bacterial_pathogens_isolated_from_urine_wound_and_stool_. Retrieved 14 October 2009. 
25. ^ "Nephroprotective activities of the aqueous seed extract of Carica papaya Linn. in carbon tetrachloride induced renal injured Wistar rats: a dose- and time-dependent study". http://www.biolmedonline.com/Articles/vol1_1_11-19.pdf. Retrieved 19 November 2009. 

External links

• Fruits of Warm Climates: Papaya and Related Species
• California Rare Fruit Growers: Papaya Fruit Facts
• Purdue: Carica papaya
• Papaya Nutrient Content
• Treating Livestock with Medicinal Plants: "Beneficial or Toxic? Carica papaya"