The soursop is adapted to areas of high humidity and relatively warm winters; temperatures below 5 °C (41 °F) will cause damage to leaves and small branches, and temperatures below 3 °C (37 °F) can be fatal. The fruit becomes dry and is no longer good for concentrate.
With an aroma similar topineapple,[5] the flavor of the fruit has been described as a combination of strawberries and apple with sourcitrus flavor notes, contrasting with an underlying thick creamy texture reminiscent ofbanana.
Annona muricata is a species of the genusAnnona of thecustard apple tree family,Annonaceae, which has edible fruit.[4][5] The fruit is usually called soursop due to its slightly acidic taste when ripe.Annona muricata is native to theCaribbean andCentral America but is now widely cultivated – and in some areas, becominginvasive – in tropical and subtropical climates throughout the world, such asIndia.[4][5]
TheA. muricata fruit is generally calledguanábana in Hispanic America, and the tree is aguanábano.
Botanical drawing showing flower, leaves, and fruit
Annona muricata is a small, upright,evergreen tree that can grow to about 10 m (33 ft) tall.[7][4][5]
Its young branches arehairy.[7] The leaves are oblong to oval, 8 to 16 cm (3.1 to 6.3 in) long and 3 to 7 cm (1.2 to 2.8 in) wide. They are a glossy dark green with no hairs above, and paler and minutely hairy to no hairs below.[7] The leaf stalks are 4 to 13 mm (0.16 to 0.51 in) long and without hairs.[7]
Flower stalks (peduncles) are 2 to 5 mm (0.079 to 0.197 in) long and woody. They appear opposite from the leaves or as an extra from near the leaf stalk, each with one or two flowers, occasionally a third.[7] Stalks for the individual flowers (pedicels) are stout and woody, minutely hairy to hairless and 15 to 20 mm (0.59 to 0.79 in) with small bractlets nearer to the base which are densely hairy.[7]
The petals are thick and yellowish. Outer petals meet at the edges without overlapping and are broadly ovate, 2.8 to 3.3 cm (1.1 to 1.3 in) by 2.1 to 2.5 cm (0.83 to 0.98 in), tapering to a point with a heart shaped base. They are evenly thick, and are covered with long, slender, soft hairs externally and matted finely with soft hairs within. Inner petals are oval shaped and overlap. They measure roughly 2.5 to 2.8 cm (0.98 to 1.10 in) by 2 cm (0.79 in), and are sharply angled and tapering at the base. Margins are comparatively thin, with fine matted soft hairs on both sides. The receptacle is conical and hairy. The stamens are 4.5 mm (0.18 in) long and narrowly wedge-shaped. The connective-tip terminate abruptly and anther hollows are unequal. Sepals are quite thick and do not overlap. Carpels are linear and basally growing from one base. The ovaries are covered with dense reddish brown hairs, 1-ovuled, style short and stigma truncate.[7] Its pollen is shed as permanent tetrads.[8]
Thefruit is oval, dark green when immature, with a leathery, inedible skin that turns yellow-green during maturity.[5] They grow to 10–35 cm (3.9–13.8 in) long,[7] with a moderately firm texture, and typically weigh around 4 kg (8.8 lb), up to a maximum of 10 kg (22 lb).[9] Their flesh is juicy, acidic, whitish, and aromatic somewhat like pineapple, although with a unique earthy aroma.[5] Most of the immature segments are seedless, whereas mature fruit may contain as many as 200 seeds.[5]
Annona muricata is tolerant of poor soil[5] and prefers lowland areas between the altitudes of 0 to 1,200 m (3,900 ft). The exact origin is unknown; it is native to thetropical regions of theAmericas and is widely propagated.[4][5] It is an introduced species on all temperate continents, especially insubtropical regions.[4][5]
The plant is grown for its 10–35 cm (3.9–13.8 in) long, prickly, green fruit, which can weigh up to 10 kg (22 lb), making it the largestAnnona fruit,[9] though not as large as the relatedjunglesopAnonidium mannii. Away from its native area, some limited production occurs as far north as southernFlorida withinUSDA Zone 10; however, these are mostly garden plantings for local consumption. It is also grown in parts ofChina andSoutheast Asia and is abundant on the Island ofMauritius. The main suppliers of the fruit are Mexico followed by Peru, Brazil, Ecuador, Guatemala, and Haiti.[10] To aid soursop breeders and stimulate further development of genomic resources for this globally important plant family, the complete genome forAnnona muricata was sequenced in 2021.[11]
Guanábana fruit on sale at a farmer's market inGoicoechea, Costa RicaGuanábana juice served at a restaurant inSan José, Costa Rica
The flesh of the fruit consists of an edible, whitepulp, some fiber, and a core of indigestible black seeds. The pulp is also used to make fruit nectar, smoothies, fruit juice drinks, as well as candies,sorbets, and ice cream flavorings.[4][5] Due to the fruit's widespread cultivation, its derivative products are consumed in many countries, such asJamaica,Mexico,Brazil,Venezuela,Colombia,[12] andFiji.[13]
Raw soursop is 81% water, 17%carbohydrates, 1%protein, and has negligiblefat (see table). In a reference amount of 100 g (3.5 oz), the raw fruit supplies 276 kilojoules (66 kilocalories) offood energy, and contains onlyvitamin C as a significant amount (23%) of theDaily Value, with no othermicronutrients in appreciable amounts (table).
TheMemorial Sloan-Kettering Cancer Center cautions, "alkaloids extracted from graviola may cause neuronal dysfunction".[17] Annonacin has been shown in laboratory research to beneurotoxic.[17][18][21] In 2010,the French food safety agency concluded that "it is not possible to confirm that the observed cases of atypical Parkinson syndrome ... are linked to the consumption ofAnnona muricata".[22]
In 2008, theFederal Trade Commission in the United States stated that use of soursop to treat cancer was "bogus", and there was "no credible scientific evidence" that the extract of soursop sold by Bioque Technologies "can prevent, cure, or treat cancer of any kind."[23] Also in 2008, a UK court case relating to the sale of Triamazon, a soursop product, resulted in the criminal conviction of a man under the terms of theUK Cancer Act for offering to treat people for cancer. A spokesman for the council that instigated the action stated, "it is as important now as it ever was that people are protected from those peddling unproven products with spurious claims as to their effects."[24]
TheMemorial Sloan-Kettering Cancer Center andCancer Research UK state that cancer treatment using soursop is not supported byreliable clinical evidence.[6][17] According to Cancer Research UK, "Many sites on the internet advertise and promote graviola capsules as a cancer cure, but none of them are supported by any reputable scientific cancer organizations" and "there is no evidence to show that graviola works as a cure for cancer".[6]
^abcdefghijklmJulia F. Morton (1987)."Soursop,Annona muricata". West Lafayette, IN: New Crop Resource Online Program, Center for New Crops & Plant Products, Department of Horticulture and Landscape Architecture, Purdue University.Archived from the original on April 25, 2018. RetrievedMay 25, 2018.
^Walker JW (1971) Pollen Morphology, Phytogeography, and Phylogeny of the Annonaceae. Contributions from the Gray Herbarium of Harvard University, 202: 1–130.
^Le Ven J, Schmitz-Afonso I, Touboul D, et al. (2011). "Annonaceae fruits and parkinsonism risk: Metabolisation study of annonacin, a model neurotoxin; evaluation of human exposure".Toxicology Letters.205:S50 –S51.doi:10.1016/j.toxlet.2011.05.197.
^abcd"Graviola". Memorial Sloan-Kettering Cancer Center. February 1, 2017.Archived from the original on November 13, 2013. RetrievedMay 25, 2018.
^Lannuzel A, Höglinger GU, Champy P, et al. (2006). "Is atypical parkinsonism in the Caribbean caused by the consumption of Annonacae?".Parkinson's Disease and Related Disorders. Journal of Neural Transmission. Supplementa. Vol. 70. pp. 153–157.doi:10.1007/978-3-211-45295-0_24.ISBN978-3-211-28927-3.PMID17017523.
