Table of contents
Papaya (Carica papaya) is a raw edible fruit. Unripe, green papayas taste a bit tart and can be processed like vegetables. Organic papayas are available.
Culinary uses of green papaya
You can eat a papaya green (unripe) or ripe. The ripe flesh has a mildly sweet taste and is reminiscent of honeydew melon, peach or apricot.
What does green papaya taste like? An unripe papaya, also known as a raw papaya, tastes neutral, tart and a little bitter.
Do you have to cook green papaya? You can, but you don't have to. Unripe papaya tastes good both raw (in salads) and cooked (in chutneys, salsas, soups, rice dishes or stews). Green papayas are excellent for refining vegan curries. You can prepare the green papaya as a vegetable like you prepare kohlrabi or zucchini.
Recognizing unripe papayas: The young papaya fruits have a green skin and light green to white flesh. The kernels (seeds) of the unripe papayas are white and inedible, but not poisonous (rather bitter). Only the black seeds of the ripe papaya are edible. They have a piquant aroma, the heat of which is reminiscent of nasturtium or pepper.
How to eat papaya? Papayas, regardless of whether they are ripe or unripe, are cut in half and the seeds removed. Ripe papayas can easily be scooped out with a spoon. Unripe, green papayas are peeled with a vegetable peeler and cut into bite-sized pieces. Even when they are not ripe, papayas enrich the raw food cuisine: the fruits can be used in a healthy papaya salad by grating them finely or cutting them into thin strips.
Southeast Asian cuisine often uses green papayas. For example, som tam, a hot, spicy salad with raw papaya, fish sauce, and shrimp, is the national dish of Thailand, Isaan (northeastern Thailand), and Laos.1 Asians traditionally enjoy the salad with sticky (or non-sticky) rice. In Laos and Isaan, the dish is usually hotter and sourer than in central Thailand.
This link will take you to our recipe for a healthy raw vegan Som Tam Salad (in German).
Note that young, green fruits do not fully ripen. The post-ripening process only begins when the fruit has reached a certain degree of ripeness, i.e., when it is slightly yellow.
When is a papaya ripe? Ripe fruits can be recognized by the consistently yellow color of the skin and when it can be pressed in with your fingers. In principle, papayas that have been cut open no longer ripen.
Very young papaya leaves can be cooked and eaten but have a bitter taste. Tea made from dried papaya leaves is said to relieve gastrointestinal problems.
Vegan recipe for Smoothie with Green Papaya
Ingredients: ½ green apple; 1 frozen banana; ½ cup peeled, chopped green papaya (raw and organic); ½ cup raw baby spinach, 1 lime.
Procedure: Put all the chopped ingredients and the lime juice in a blender or smoothie maker and puree. Depending on the desired consistency, you can add some fresh tap water. Pour the green smoothie into a cocktail glass and garnish with dried goji berries.
To find vegan recipes with green papaya follow the reference: "Recipes that have the most of this ingredient".
Not only vegans and vegetarians should read this: A Vegan Diet Can Be Unhealthy. Nutrition Mistakes. |
Purchasing - storage
Green papayas are rare in temperate countries and plentiful in tropical and subtropical countries. In temperate countries, Asian markets or larger department stores with a good selection of exotic fruits may offer green papaya fruits. Organically produced green papayas are sometimes available in organic supermarkets- or you can order them online. In this unripe state, the exotic fruit can be shipped without any loss of quality. Papayas do not have a specific season in their countries of origin, such as Thailand, Hawaii or South Africa, they grow all year round.25 The same applies to Spanish papayas, but a harvest time between October and November is recommended here.26
When buying, you should make sure that the green papaya is still very firm. If you press the green skin with your thumb, it shouldn't yield to the pressure. "Kaik Tam" is a well-known papaya variety. It is unripe when it is about 20 cm long and weighs 500 grams. When wrapped in foil, it resembles a thicker cucumber. Green papaya may be found under the name salad papaya.
Storage tips
The optimal storage temperature for green papayas is 12-13 °C. If the fruit has been sliced or halved, the seeds should be removed before storing in the refrigerator. When covered with foil or in a closed container, they keep for about 2 days. Half-ripe papayas can be recognized by their skin, which is no longer green but rather yellowish. At this stage, the fruit can continue to ripen if stored at room temperature. Regular checking of the ripening by lightly pressing the shell is recommended.3
Ingredients - nutritional values - calories
At 35 kcal/100g, unripe fruits have even fewer calories than ripe papayas. In contrast to their low carbohydrate, protein and fat content, green papayas are high in vitamins.
According to estimates by the Hawaii Institute of Tropical Agriculture and Human Resources, raw green papaya contains 75 mg of vitamin C (ascorbic acid) per 100 g, which covers 94% of the daily requirement.30 This puts it not far behind fresh aronia berries (81 mg/100g) and raw cabbage vegetables such as brussels sprouts (85 mg) or broccoli florets (93 mg). However, it does not come close to the high values of the yellow sweet pepper (184 mg).17
As with the ripe fruit, the vitamin C levels of green specimens are subject to fluctuations, making regular comparisons between immature and ripe samples difficult. However, it is assumed that the content of ascorbic acid increases with increasing maturity.30
Papaya fruits are high in fiber and contain the enzyme papain, which is much more abundant in green papayas than in ripe papayas.4 Ripe papayas provide much more vitamin A (47 µg/100g).17
In addition, lycopene (antioxidant), magnesium, potassium, pantothenic acid, riboflavin, niacin, selenium, iron and phosphorus are also found in papaya.17,30
You can find the total ingredients of green papaya, the coverage of the daily requirement and comparison values with other ingredients in our nutrient tables. In the article Nutrients explained you will get a detailed insight into the topic.
Health effects
Are green papayas healthy? Unripe papayas help with stomach problems, duodenal ulcers, diaphragmatic rupture and heartburn. This is because they neutralize excess stomach acid. In addition, they have a positive effect in biliary dyspepsia, chronic inflammation of the pancreas, various intestinal diseases and infectious diarrhea.5
The enzyme papain is primarily used by the plant itself to ward off pests. It is found in high concentrations in the milky juice (latex) of the unripe, green papaya peel - as well as in the white kernels.22 This proteolytic enzyme also breaks down proteins - like the pepsin2 in gastric juice. Thus, this active ingredient promotes the digestion of food.22
The plant milk and the papaya pulp are effective against intestinal parasites,2 especially against the pork roundworm (Ascaris suum), which can infect not only pigs but also humans.6 Papaya leaf extracts help against symptoms of dengue fever, which are transmitted by mosquitoes in many areas where papaya is cultivated.7
The high vitamin A content in ripe papayas alleviates skin diseases such as eczema, furunculosis and acne.4 Fermented papayas are used as a dietary supplement in combined therapies for Alzheimer's, cancer, or allergic reactions due to their antioxidant effects.15
Dangers - intolerances - side effects
Since green papayas contain the papaya latex, contact with the eyes should be avoided during processing. Otherwise, severe irritation may occur. In the case of a latex allergy, the latex contained in unripe papayas can cause cross-reactions. Some people are also allergic to papaya bee pollen, papain, or other enzymes found in the fruit.8
Although in many Asian countries, breastfeeding women like to eat green papaya salad to stimulate milk production, there is no scientific evidence that the galactagogues (galactogens) contained in green papayas have a positive effect on milk production.9 Pregnant women should avoid unripe papayas. The high latex concentration in unripe or half-ripe papayas triggered uterine contractions in experiments with rats. In addition, the latex in green papayas can cause pregnant women to bleed at the edge of the placenta, leading to an earlier delivery.12 Fully ripe papayas do not pose a significant risk.10,11
A study in animals has shown that the ingredients from papaya seeds inhibit fertility, but only temporarily. The number of sperm cells in the semen was back to normal 60 days after the end of treatment. Primitive peoples are said to have made use of this effect in the past.13
When consuming high doses of papaya leaf extracts (possible with papaya capsules), the papain contained can lead to hypoglycemia. However, these extracts also have antioxidant effects and improve the lipid profile, liver, and pancreas functions in diabetic rats.14
Use as a medicinal plant
Papayas are used in many areas of medicine,12 however Commission E only monographed the leaves as a medicinal plant (Caricae papayae folium).
The papain contained in papayas is isolated using special methods and used to improve the treatment of herniated discs (chemonucleolysis).16
Traditional medicine - naturopathy
Papaya has numerous uses in folk medicine. Unripe papaya is used as a home remedy for diarrhea, worms and high blood pressure. An infusion of flowers, parts of the bark (against toothache), the latex juice and the leaves (against malaria) are said to have a health-promoting, and especially anti-inflammatory effect when used internally or externally. Indigenous peoples cleaned wounds with the milky juice of papaya.
Unripe papaya is not only known as a contraceptive, but also as a tool for abortion in some regions. Therefore, primitive peoples also used it in high doses as an abortifacient.
Ecological footprint - animal welfare
Papayas are cultivated in many subtropical areas of the world. In Europe it is cultivated in south-eastern Spain. Papaya plants are often grown in protected greenhouses to create optimum growing conditions. Here they receive the required amount of water via drip systems and fogging to prevent phenomena such as "growing" arrest or withering of the leaves. In winter, additional heating ensures sufficient warmth. The amount of water supplied increases over the "growing" phase.26 Approximately 460 liters of water are needed to produce 1 kg of papayas.27
Papayas harvested unripe from Brazil or Thailand can be transported to Europe by ship, so they have a smaller ecological footprint from CO2 emissions. Fruits that are already ripe or very large have a limited shelf life and must be transported by plane. As a result, massive amounts of CO2 are released into the atmosphere. When purchasing, the transport method is reflected in the price, so airborne goods are significantly more expensive than fruit transported by ship.28
So far, few pests of the papaya plant are known in Spain, which is why organic cultivation is an option.26 On other continents, such as Brazil, however, pesticides are still used to a large extent, and residues can also be found in the fruit.29 Accordingly, organic goods should be preferred when purchasing.
Worldwide occurrence - cultivation
The origin of papayas is not clear. The first domestication is believed to be in Central America and not in South America.2 The papaya is a widely cultivated plant in subtropical and tropical areas. Today, papaya is grown in Africa, Asia and South and Central America. Papaya is popular in the Caribbean Islands, Florida, Texas, California and Hawaii.1
Growing wild
Carica papaya does not grow wild. Related wild species of Carica are found in Central and South America.2 For details, see the article on papaya.
Cultivation - harvest
Seeds of a ripe papaya can be used for sowing in pots. Papaya needs loose, nutrient-rich substrate for good root development. Coconut substrate, peat or special growing soil with a pH value of no more than 7 are suitable. The plant substrate should be free of pests and fungi, which store-bought products usually are. To be on the safe side, you can heat it in the oven for about 15 minutes to at least 160 °C before using it. The substrate must be slightly damp for this.18
After sowing, the seeds need a lot of heat with indirect light. The germination period is approx. 2–6 weeks and the ideal temperatures are between 24 and 30 °C. To ensure constant moisture but not wetness in the substrate, it is best to use a sprayer for watering. Two weeks after germination, place the container in a sunny, wind-protected place. Watering the papaya tree is quite a challenge, especially in winter. Papaya tree needs a minimum of 10 °C to hibernate.3
Papaya plants thrive in subtropical or tropical climates. They can grow up to 3 m high within a year. Papayas sometimes bear the first fruits after a year. However, the peak production is in the 2nd to 4th year, when the plants reach heights of up to 10 m, depending on the variety. Lower temperatures produce smaller fruits. Papayas like full sun exposure and well-drained, porous soil.
Additional information
The papaya (Carica papaya) belongs to the family Caricaceae.
The fleshy consistency of the fruits earned them the nickname "melon tree fruits" by the conquerors from Europe. Botanically, however, it is neither a tree nor a fruit. The plant is much more of a perennial that used to bear smaller berries and now has giant berries.3 The papaya plant does not produce secondary wood, is often hollow inside, and is often waterlogged at the base.2
Papayas have male and female plants that are indistinguishable from each other when young. This sex differentiation also complicates plantation cultivation. You can remedy this by placing several young plants in the same seed hole, recognizing the male plants based on the flowers, and thinning them out. To ensure good pollination, keep about 10% of male plants in the plantation.2
There are also hermaphrodite varieties, i.e., those with both sexes on one plant. These hermaphrodites produce slightly smaller fruits through self-fertilization, which are very suitable for consumption, because of higher fruit set. However, due to the heterozygous genome (presence of different alleles in diploid chromosome sets), the hermaphrodite flower can "change" over the course of life. This means that an occasional "sex reversal" can occur in hermaphrodite heterozygous flowers (Mm and MHm). Exceptions are those with two purely female alleles (mm). (M= male, MH= hermaphroditic, m= female).2
The cultivation method in conventional monocultures often causes the tall tropical trees to become ill. They are very susceptible to pathogens such as nematodes, insects, fungi and especially viruses.
Mass outbreaks of papaya ringspot virus (PRV or PRSV) occurred in Hawaii in 1992. The viruses are transmitted by insects. There is no antidote, the only thing that helps is cutting down the plants that have been in use for a few years.19 In the 1990s, scientific researchers in New York and Hawaii developed virus-resistant varieties and these have been used in Thailand, Jamaica, Venezuela and Brazil since 1998/1999.20
These genetically modified fruits can also be imported into the USA, Japan, and many other countries without hesitation; Europe is still exempt. The few organically cultivated plantations have major problems with pollen from the genetically modified varieties. This contamination can render their entire harvest unusable for organic certification.21
Alternate names
Papayas are sometimes also called tree melons or cress figs. Latin synonyms of Carica papaya are Carica hermaphrodita, C. mammaya, C. quinqueloba, Papaya carica, Papaya communis, Papaya cucumerina, and Papaya vulgaris.21
In English, papaya is sometimes wrongly called pawpaw or papaw.2 Papaya is called "malakor" in Thai.22,23
Other applications
The food industry also makes use of papaya ingredients. Papain is used to clarify beer. It also helps in the tanning of leather. It is used in the textile industry to prevent wool and silk from shrinking and felting.22 The rubber of the papaya tree is also processed into chewing gum.21
Bibliography - 23 Sources
1. | Wikipedia Englisch Papaya. |
2. | Brücher H. Tropische Nutzpflanzen. Berlin: Springer. 1977. |
3. | WIFSS Western Institute for Food Safety & Security. Papayas. 2016. |
4. | Roger JDP. Heilkräfte der Nahrung. Zürich: Advent-Verlag. 2006. |
5. | Osato JA, Santiago LA et al. Antimicrobial and antioxidant activities of unripe papaya. Life Sciences. 1993;53(17). |
6. | Satrija F, Nansen P et al. Effect of papaya latex against Ascaris suum in naturally infected pigs. Journal of Helminthology. 1994;68(4). |
7. | Ahmad N, Fazal H et al. Dengue fever treatment with Carica papaya leaves extracts. Asian Pacific Journal of Tropical Biomedicine. 2011;1(4). |
8. | Blanco C, Ortega N et al. Carica papaya pollen allergy. Annals of Allergy, Asthma Immunology. 1998;81(2). |
9. | Bethesda MD. Drugs and Lactation Database. Papaya. National Library of Medicine (US). 2018. |
10. | Adebiyi A, Adaikan PG, Prasad RN. Papaya (Carica papaya) consumation is unsafe in pregnancy: fact or fable? Scientific evaluation of a common belief in some parts of Asia using a rat model. British Journal of Nutrition. 2002;88(2). |
11. | Meera S, Ugendra K. Effect of unripe Carica papaya on uterus. Institute of Pharmaceutical Sciences India. 2013;4(3). |
12. | Aravind G, Debjit B et al. Traditional and medicinal uses of Carica papaya. Journal of Medicinal Plant Studies. 2013;1(1). |
13. | Lohiya NK, Mishra PK et al. Reversible azoospermia by oral administration of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in rabbits. Adv Contracept. 1999;15(2). |
14. | Juárez-Rojop IE, Díaz-Zagoya JC et al. Hypoglycemic effect of Carica papaya leaves in streptozotocin-induced diabetic rats. |
15. | Wikipedia Papaya. |
16. | Oppel F, George HH et al. Die Chemonukleolyse mit Chymopapain: Erfahrungen an 100 Fällen. Lendenwirbelsäulenerkrankungen mit Beteiligung am Nervensystem. Neuroorthopädie. Springer: Heidelberg. 1984. |
17. | Müller-Jahncke WD, Friedrich C, Meyer U. Arzneimittelgeschichte. 2. überarbeitete Auflage. Wissenschaftliche Verlagsgesellschaft mbH: Stuttgart. 2005. |
18. | Kübelpflanzeninfo.de Papaya. |
19. | Pini U. Das Bio-Food Handbuch. Ullmann: Hamburg, Potsdam. 2014. |
20. | Gonsalves D. Transgenic Papaya in Hawaii and Beyond. The Journal of Agrobiotechnology Management & Economics. 2004;7(1-2). |
21. | Spektrum.de Carica papaya. |
22. | Online.uni-marburg.de Papain. |
23. | thai-thaifood.de Grüne Papaya (Malakor). |
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