Dragon fruit

Dragon Fruit, Raw (100g)
Nutritional value per 100 g (3.5 oz)
Energy	57 kcal (240 kJ)
Carbohydrates	15.2 g
Sugars	9.75 g
Dietary fiber	3.1 g
Fat	0.14 g
Protein	0.36 g
Vitamins
Vitamins and minerals
Vitamins	Quantity %DV†
Thiamine (B1)	1% 0.012 mg
Riboflavin (B2)	2% 0.026 mg
Niacin (B3)	1% 0.161 mg
Vitamin B6	2% 0.026 mg
Folate (B9)	2% 7 μg
Choline	1% 5.1 mg
Vitamin C	5% 4.3 mg
Vitamin E	1% 0.12 mg
Vitamin K	4% 4.4 μg
Minerals	Quantity %DV†
Calcium	1% 9 mg
Iron	1% 0.18 mg
Magnesium	2% 7 mg
Phosphorus	1% 12 mg
Potassium	4% 116 mg
Sodium	0% 1 mg
Zinc	1% 0.1 mg
Other constituents	Quantity
Water	84 g
	Link to USDA Database entry
	†Percentages estimated using US recommendations for adults, except for potassium, which is estimated based on expert recommendation from the National Academies.; Source: https://fdc.nal.usda.gov/food-details/2344729/nutrients

Dragon fruit, also called pitahaya or pitaya, is the fruit of several species in the cactus genus Selenicereus, particularly Selenicereus undatus, native to the southern regions of Mexico and the Pacific coast of Guatemala, Costa Rica and El Salvador.^[1]^[2] Its cultivation has expanded to other regions including China, Qatar and Saudi Arabia.

Description

The dragon fruit is a hardy and succulent cactus, as it is drought resistant, possessing long triangular stems. It often intertwines itself with nearby trees, taking moisture from their bark and climbs 8 to 10 meters from the ground without penetrating the ground. The flower of the dragon fruit is tubular and hermaphroditic due to its dehydration.

It only opens once in the night and its aroma attracts insects. It is self pollinating, but it can also pollinate with other plants, with bats being their biggest pollinators in their natural habitat. The formation of the fruit from pollination to harvest takes 4 to 8 weeks depending on the temperatures.

The fruit is oval shaped, 10 cm by 6 cm. It presents itself from birth as green, turning yellow or red depending on the cultivar. As it develops, it grows scaly skin.

The rind presents groups of sharp and hard spines, detaching with ease. It is a flavorful fruit which contains a smooth, sweet and soft pulp in both yellow and red varieties, but red varieties usually have less sugar.^[3]

Species

Dragon fruits mainly come in three types:^[4]

Selenicereus undatus has pink-skinned fruit with white flesh. This is the most commonly seen "dragon fruit". It is also known as the following: night blooming cereus, strawberry pear, pitahaya roja, reina de la noche (queen of the night), formerly Hylocereus undatus.
Selenicereus costaricensis has red-skinned fruit with red flesh. It is also known as Costa Rica nightblooming cactus, Costa Rican pitaya, Hylocereus costaricensis and Hylocereus polyrhizus.
Selenicereus megalanthus has yellow-skinned fruit with white flesh. S. megalanthus is commonly known as "yellow dragon fruit", "yellow pitahaya", "kirin fruit" or "yellow pitaya". It is also formerly known as Hylocereus megalanthus.

The fruit weighs around 150 to 600 grams (5+1⁄2 to 21 oz); some may reach 1 kg (2 lb 3 oz).^[5] Early imports from Colombia to Australia were designated Hylocereus ocampensis (or Cereus repandus, the red fruit) and Cereus triangularis (supposedly, the yellow fruit or the three-sided cross-section of the stem).

Properties

The peel is either a purplish green or yellow. The pulp has small black seeds. It loses its smell when it gets warm. The red dragon fruits have either white or red pulp; the red pulp is harder to cultivate, and as such, less frequent, but the flavor is more intense than the ones with white pulp.

The fruits are sensitive to pressure making them difficult to transport. In Europe, it is possible to find them in supermarkets; in Central America they are available from July to December and in Vietnam from January to July. The fruits from Thailand come by plane all year.

The dragon fruit helps with red blood cell creation. 90% of the fruit is composed of water and it is rich in iron, calcium and phosphorus. It also contains vitamins B, C and E. It is rich in fiber, which helps intestinal transit. Its energy value is 210kJ/100g.

Grafting improves the nutritional profile and organoleptic quality (?) of the yellow dragon fruit.^[8]

Culinary uses

The fruit's texture is sometimes likened to that of the kiwifruit because of its black, crunchy seeds. The seed oil contains linoleic acid.^[9] Dragon fruit is used to flavor and color juices and alcoholic beverages, such as "Dragon's Blood Punch" and the "Dragotini".^[10] The flowers can be eaten or steeped as tea.^[11]

The red and purple colors of some Selenicereus fruits are due to betacyanins, a family of pigments that includes betanin, the same substance that gives beets, Swiss chard and amaranth their red color.^[12]^[13]

Seed oils

The fatty acid compositions of the seed oils of Selenicereus costaricensis, syn. Hylocereus costaricensis (red-fleshed pitaya) and Selenicereus undatus, syn. Hylocereus undatus (white-fleshed pitaya) were similar: myristic acid (negligible), palmitic acid (17%), stearic acid (5%), palmitoleic acid (about 1%), oleic acid (22%), cis-vaccenic acid (3%), linoleic acid (50%) and α-linolenic acid (1%).^[14]

Production

The main producers in the world for Dragon Fruit are Nicaragua (biggest producer in Central America of Selenicereus sp.). Colombia (biggest producer of Selenicereus megalanthus) the Dominican Republic (Selenicereus monacanthus was used by the Tainos), Peru, Ecuador, Spain (especially in San Miguel de Salinas) (the latter 3 are producers of Selenicereus sp.), Vietnam (biggest producer of Selenicereus undatus in south east Asia), Thailand, Malaysia, Qatar and Israel.^[15]

Cultivation

After a cleaning of the seeds from the pulp of the dragon fruit, the seeds are stored when dried as the ideal fruit is unblemished and overripe.

The seeds grow in a compost or potting soil mix, including pots indoors. The cacti germinate after between 11 and 14 days after shallow planting. As they grow, the plants will find something to climb on, normally involving aerial roots down from the branches, usually in addition to basal roots. Once the plant reaches 4.5 kilograms (10 pounds) in weight, the plant may flower.^{[clarification needed]}

Commercial plantings can be done at a density between 1,100 and 1,350 per hectare (445 and 546/acre). Plants can take up to 60 months (260 weeks) to come into full commercial production, at which stage yields of 20 to 30 metric tons (22 to 33 short tons) can be expected.^[16]

Dragon fruit flowers bloom overnight and usually wilt by the evening.^[17] They rely on nocturnal pollinators such as bats or moths for fertilization. Self-fertilization will not produce fruit in some species and while crossbreeding has resulted in several "self-fertile" varieties, cross-pollinating with a second, genetically distinct plant of the same species generally increases fruit set and quality. This limits the capability of home growers to produce the fruit. However, the plants can flower between three and six times per year depending on growing conditions. Like other cacti, if a healthy piece of the stem is broken off, it may take root in the soil and become its own plant.^{[citation needed]}

The plants can endure temperatures up to 40 °C (104 °F) and short periods of frost but will not survive long exposure to freezing temperatures. The cacti thrive most in USDA zones 10–11 but may survive outdoors in zone 9a or 9b.^[2]^[18]

Selenicereus has adapted to live in dry tropical climates with a moderate amount of rain. In numerous regions, it has escaped cultivation to become a weed and is classified as an invasive weed in some countries.^[1]

Pests and diseases

Stems and fruits are susceptible to several diseases caused by fungi, bacteria, nematodes and viruses.^[19] Overwatering or excessive rainfall can cause the flowers to drop, and fruit to rot,^[20] such as the bacterium Xanthomonas campestris that causes the stems to rot. Dothiorella fungi can also cause brown spots on the fruit, and other fungi known to infect the fruit include Botryosphaeria dothidea, Colletotrichum gloeosporioides and Bipolaris cactivora.^[19]

Gallery

Dragon fruit "tree"
Dragonfruit farm in Andhra Pradesh, India
Plantation in Naozhou Island
Nocturnal flowering
Yellow S. megalanthus
Red S. costaricensis
Jus buah naga, purple dragon fruit juice, Indonesia
Red, yellow and white fruits
Dress for a folk dance called Flor de Pitahaya "Pitahaya Flower" from Baja California Sur displayed at the Museo de Arte Popular in Mexico City
Dissected dragon fruit
A piece of red dragon fruit from Kenya
A piece of red dragon fruit from China
Fresh ripe dragon fruit in Vietnam