Papaya

The papaya is a plant called Carica papaya. It is one of 3 accepted species in the genus Carica, which belongs to the family Caricaceae. The name is pronounced puh-PIE-uh, and the American pronunciation is puh-PAH-yuh (US).

The papaya was first grown in Mesoamerica, in the area of what is now southern Mexico and Central America. Today, it is grown in many countries with a tropical climate.

In 2024, India grew more papayas than any other country. It made up about one-third of the world total.

Etymology and common names

The word papaya comes from the Arawakan languages of the West Indies. It is also the name for the plant itself. People in English first used the word around 1600 for both the fruit and the tree.

In some places, such as Australia, the papaya may be called papaw or pawpaw. In Australian English, pawpaw and papaya are used for different cultivars of the same plant. Pawpaw is used for bigger fruits with yellow flesh. Papaya is used for longer, oval fruits with orange-red flesh. In the United States, papaw and pawpaw are names for a different plant and fruit, Asimina triloba. That plant is not related to the papaya.

Description

The papaya is a large plant. It usually has one stem and grows 5 to 10 m (16 to 33 ft) tall. Its spirally arranged leaves grow only at the top of the trunk. The lower trunk has scars where old leaves and fruit were once attached. The leaves are large, 50–70 cm (20–28 in) across, and deeply palmately lobed, with seven lobes. Every part of the plant contains latex, a milky liquid that flows through laticifers.

Papaya plants are dioecious, which means male and female flowers grow on separate plants. The flowers have five parts and smell sweet. They open at night and are spread by wind or insects. Male and female flowers grow in the leaf joints, in small clusters called dichasia.

The fruit is a large berry, about 15–45 cm (6–17+3⁄4 in) long. It is ready to eat when it feels soft and its skin has turned amber to orange. Many black seeds are attached to the walls inside its large central cavity. The skin, flesh, and seeds contain many phytochemicals, including carotenoids, polyphenols, and benzyl isothiocyanates. The yellow skin has lutein and beta-carotene, while the red flesh has lycopene. The seeds also contain prunasin, a cyanogenic substance. The green fruit contains papain, a cysteine protease enzyme that is used to make meat softer (see below).

Distribution and habitat

Papaya comes from warm, tropical parts of the Americas, starting in southern Mexico and Central America. It is also thought of as native to southern Florida, where earlier peoples, the ancestors of the Calusa, grew it no later than AD 300. Spanish explorers brought papaya to the Old World in the 1500s. Today, it grows in almost every tropical area, including Hawaii, Central Africa, India, and Australia. This is why it is called pantropical.

Wild papaya usually grows in tropical forests that have been naturally disturbed. After big hurricanes, it can be found in large numbers on Everglades hammocks, but otherwise it is not common there. In the rain forests of southern Mexico, papaya grows and spreads quickly in openings in the tree cover. It does not do well in thick, mature forests where the treetops block most of the light.

Diseases

See also: List of papaya diseases

Papaya plants can get sick from several viruses. Papaya ringspot virus is a well-known virus in Florida. It causes yellow leaves and circular, C-shaped marks on the fruit. Viruses also lower the quality of the fruit, especially its taste. As of 2010, the only way to protect papaya from this virus was genetic modification. The papaya mosaic virus can damage a plant until only a small tuft of leaves is left. It can also infect the fruit at any stage of growth.

Fungi and similar organisms cause problems too. Anthracnose attacks ripe fruit and causes sunken brown or black spots. Powdery mildew looks like white powder on the leaves, but it is not as serious as other diseases. The oomycete Phytophthora can cause root rot, stem rot, and fruit rot. Infected fruit may be harmful to people who eat it.

Pests also harm papaya. The papaya fruit fly lays many eggs inside the fruit. The eggs hatch, and the larvae feed on the seeds and inner parts. Then they leave the fruit and develop in the soil. The two-spotted spider mite feeds on the underside of leaves, which turn yellow, gray, or bronze. If the mites are not controlled, they can cause the fruit to die. Papaya whiteflies eat the leaves, which harms the fruit. Papayas are also a common home for fruit flies like A. suspensa. These flies lay their eggs in overripe or spoiled papayas. This has caused large costs for farmers in Central America.

Cultivation

Old records from travelers and plant experts in the 1700s suggest that papaya seeds were carried from the Caribbean to Malacca and then to India. From Malacca or the Philippines, papaya spread across Asia and into the South Pacific. Francisco de Paula Marín, a Spanish explorer and plant expert, is often given credit for bringing papaya to Hawaii. He brought it from the Marquesas Islands in the early 1800s. Papaya plants can be male, female, or hermaphrodite. Male plants make only pollen and never make fruit. Female plants make small fruits that cannot be eaten unless they are pollinated. Hermaphrodite plants can pollinate themselves because their flowers have both male stamens and female ovaries. Almost all commercial papaya farms grow only hermaphrodites.

Papaya first came from southern Mexico (especially Chiapas and Veracruz), Central America, northern South America, and southern Florida. Today it is grown in most tropical countries. The plant grows quickly and bears fruit within three years. However, it is very sensitive to frost, so it grows best in tropical climates. It prefers sandy soil that drains well, because standing water can kill it within 24 hours. Two kinds are commonly grown: one with sweet red or orange flesh, and one with yellow flesh. In Australia, these are called "red papaya" and "yellow papaw." Large red-fleshed papayas are commonly grown in Mexico and Belize.

In 2011, Philippine researchers used hybridizing to combine papaya with Vasconcellea quercifolia. The new plant resists papaya ringspot virus. Carica papaya was the first transgenic fruit tree to have its genome sequenced. After a virus outbreak in Hawaii in 1998, genetically altered papaya was approved. By 2010, 80% of Hawaiian papaya plants were genetically modified. University of Hawaiʻi scientists gave the modified seeds to farmers at no cost. In 2024, the world grew 15 million tonnes of papayas, with India leading.

Toxicity

Unripe papaya gives off a sticky liquid called latex. This liquid can irritate the skin and, in some people, cause an allergic reaction. The enzyme papain can act as an allergen for people who are sensitive to it. Meat that has been softened with it may cause an allergic reaction.

Culinary use

Ripe papaya is usually eaten raw, with the skin and seeds removed. The black seeds can also be eaten. They have a sharp, spicy taste. Unripe green papaya is usually cooked because of its latex. Green papaya and its latex contain papain, which is used to tenderize meat. Indigenous Americans, people of the Caribbean, Pacific Islands, and the Philippines have all used it this way. Some powdered meat tenderizers contain it. Papaya should not be used in foods that set with gelatin, such as jelly or aspic, because the enzymatic properties of papain stop gelatin from setting.

Raw papaya pulp is 88% water and 11% carbohydrates. It has very little fat or protein. A 100 g serving provides 43 kilocalories. It is a good source of vitamin C (69% of the Daily Value, DV) and a moderate source of folate (10% DV). Green papaya is used in Southeast Asian cooking, either raw or cooked. In some parts of Asia, its young leaves are steamed and eaten like spinach. Papayas became part of Filipino cuisine after the Manila galleons brought them to the islands. There, unripe fruit is julienned and pickled into atchara. Green papaya is also used in dishes such as okoy, tinola, ginataan, lumpia, and empanada, especially in northern Luzon. In Indonesian cuisine, unripe fruit and young leaves are boiled for lalab salad. Flower buds are sautéed and stir-fried with chilies and green tomatoes as a Minahasan dish. In Lao and Thai cuisine, green papaya is used to make spicy salads. In Laos these are called tam maak hoong or tam som, and in Thailand they are called som tam. It is also used in Thai curries such as kaeng som. In Samoa, the fruit was introduced in 1839 via Tonga, where it is called ʻesi in Samoan. There it is mixed with local cocoa to make a pudding called koko ʻesi. In Brazil and Paraguay, unripe fruits are used to make sweets or preserves.

Traditional medicine

In traditional medicine, people thought papaya leaves could help treat malaria. People also used them as an abortifacient, a purgative (something that empties the body), and they smoked them to ease asthma. In Caribbean regions during the 20th century, the leaves were boiled into a decoction.