The pomelo (/ -/, POM-il-oh, PUM-; Citrus maxima), from the family Rutaceae, is the largest citrus fruit, and the principal ancestor of the grapefruit. It is a natural, non-hybrid, citrus fruit, native to Southeast Asia. Similar in taste to a sweet grapefruit, the pomelo is commonly consumed and used for festive occasions throughout Southeast Asia. As with the grapefruit, phytochemicals in the pomelo have the potential for drug interactions.
The pomelo tree may be 5–15 meters (16–50 feet) tall, possibly with a crooked trunk 10–30 centimeters (4–12 inches) thick, and low-hanging, irregular branches. Their leaf petioles are distinctly winged, with alternate, ovate or elliptic shapes 5–20 cm (2–8 in) long, with a leathery, dull green upper layer, and hairy under-leaf. The flowers — single or in clusters — are fragrant and yellow-white in color.
The fruit is large, 15–25 cm (6–10 in) in diameter, usually weighing 1–2 kilograms (2–4 pounds). It has a thicker rind than a grapefruit, and is divided into 11 to 18 segments. The flesh tastes like mild grapefruit, with a little of its common bitterness (the grapefruit is a hybrid of the pomelo and the orange). The enveloping membranes around the segments are chewy and bitter, considered inedible, and usually discarded. There are at least sixty varieties. The fruit generally contains a few, relatively large seeds, but some varieties have numerous seeds.
According to the Oxford English Dictionary, the etymology of the word "pomelo" is uncertain. It may be derived from Dutch pompelmoes. Its botanical name, Citrus maxima, means "the biggest citrus". In English, the word "pomelo" (also spelt pummelo, pumelo, pomello, pommelo) has become the more common name, although "pomelo" has historically been used for grapefruit.
After introduction into Barbados by 'Captain Shaddock' of the East India Company (apparently Philip Chaddock, who visited the island in the late 1640s), the fruit was called shaddock in English. From there the name spread to Jamaica in 1696. The fruit is also known as jambola in varieties of English spoken in South Asia.
|Nutritional value per 100 g (3.5 oz)|
|Energy||159 kJ (38 kcal)|
|Dietary fiber||1 g|
|†Percentages are roughly approximated using US recommendations for adults. |
Source: USDA FoodData Central
Raw pomelo flesh is 89% water, 10% carbohydrates, 1% protein, and contains negligible fat (table). A 100 gram reference amount provides 159 kilojoules (38 kilocalories) of food energy, and is rich in vitamin C (73% of the Daily Value), with no other micronutrients in significant content (table).
Pomelo may cause adverse effects, similar to those caused by grapefruit and some other citrus fruits, through the inhibition of cytochrome P450-mediated metabolism of prescription drugs such as anti-hypertensives and anticoagulants.
Possible non-hybrid pomelos
The pomelo is one of the original citrus species from which cultivated citrus fruits have been hybridized, others being citron, mandarin, and to a lesser extent, papedas and kumquat. In particular, the common orange is presumed to be a naturally occurring hybrid between the pomelo and the mandarin, with the pomelo as larger and firmer of the two. The grapefruit was originally also presumed to be a naturally occurring hybrid of the pomelo and the mandarin; however, genome analysis conducted more than two centuries after this presumption was made shows that it is actually a backcrossed hybrid between a pomelo and a sweet orange which is why 63% of the grapefruit's genome comes from the pomelo. 
The pomelo is employed today in artificial breeding programs:
- The common sweet orange (Citrus × sinensis) is a pomelo × mandarin hybrid
- The bitter orange (Citrus × aurantium) is another pomelo × mandarin hybrid
- The tangelo is a hybrid between pomelo or grapefruit and any tangerine; it generally has a thicker skin than a tangerine and is less sweet
- 'K–Early' ('Sunrise Tangelo')
- 'Minneola tangelo': Bowen grapefruit × Dancy tangerine
- 'Orlando' (formerly 'Take'): Bowen grapefruit × Dancy tangerine (pollen parent)
- 'Seminole': Bowen grapefruit × Dancy tangerine
- 'Thornton': tangerine × grapefruit, unspecified
- 'Ugli fruit' (Jamaican tangelo): mandarin × grapefruit, probable (wild seedling)
- Grapefruit is a pomelo backcross: pomelo × sweet orange (see above)
- Forbidden fruit: another Caribbean pomelo/sweet orange cross
- 'Nova': Clementine × Orlando tangelo cross
- The Oroblanco and Melogold grapefruits are hybrids between Citrus maxima and the grapefruit
- Mandelos: pomelo × mandarin
- Mato buntan: a variety in Taiwan
- Hyuganatsu is a pomelo hybrid
- Kawachi Bankan: ujukitsu x unidentified
The juice can be drunk, and the rind is used to make preserves, or may be candied. In Brazil, the thick skin may be used for making a sweet conserve, while the spongy pith of the rind is discarded. In Sri Lanka, it is often eaten as a dessert, sometimes sprinkled with sugar. In large parts of Southeast Asia where pomelo is native, it is commonly eaten as a dessert, often sprinkled with salt or dipped in a salt mixture, but it may instead be made into salads. In the Philippines, a pink beverage is made from pomelo and pineapple juice.
The seeds of the pomelo are monoembryonic, producing seedlings with genes from both parents, but they are usually similar to the tree they grow from and therefore pomelo are typically grown from seeds in Asia. Seeds can be stored for 80 days at a temperature of 5 °C (41 °F) with moderate relative humidity. Citrus maxima is usually grafted onto other citrus rootstocks outside Asia to produce trees that are identical to the parent; high-quality varieties are propagated by air-layering or by budding onto favored rootstocks.
The physical and chemical characteristics of pomelo vary widely across South Asia.
Flowering and fruiting branch with numbered fruit segment and flower section, chromolithograph by P. Depannemaeker, c. 1885, after B. Hoola van Nooten
Vertical cross section
Pomelo after being cut
Pink pomelo juice vesicles
Pomelo on tree, has fruit and blossoms at the same time
Closeup of pomelo petiole
Tam som-o nam pu: spicy Thai pomelo salad with crab extract
The large segments inside a pomelo, containing the fruit’s juice vesicles.
- Botanic Gardens Conservation International (BGCI).; IUCN SSC Global Tree Specialist Group (2019). "Citrus maxima". IUCN Red List of Threatened Species. 2019: e.T62042732A147027490. doi:10.2305/IUCN.UK.2019-2.RLTS.T62042732A147027490.en. Retrieved 19 November 2021.
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