Soursop

Appearance

"Annona muricata" is a small, upright, evergreen tree that can grow to about 30 feet tall.

Its young branches are hairy. Leaves are oblong to oval, 8 centimetres to 16 centimetres long and 3 centimetres to 7 centimetres wide. They are a glossy dark green with no hairs above, and paler and minutely hairy to no hairs below. The leaf stalks are 4 millimetres to 13 millimetres long and without hairs.

Flower stalks are 2 millimetres to 5 millimetres 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. Stalks for the individual flowers are stout and woody, minutely hairy to hairless and 15 millimetres to 20 millimetres with small bractlets nearer to the base which are densely hairy.

The petals are thick and yellowish. Outer petals meet at the edges without overlapping and are broadly ovate, 2.8 centimetres to 3.3 centimetres by 2.1 centimetres to 2.5 centimetres, 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 centimetres to 2.8 centimetres by 2 centimetres, 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 millimetres 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. Its pollen is shed as permanent tetrads.

The fruits are dark green and prickly. They are ovoid and can be up to 30 centimetres long, with a moderately firm texture. Their flesh is juicy, acidic, whitish and aromatic.

Naming

*"Annona muricata" var. "borinquensis"

Distribution

"Annona muricata" is tolerant of poor soil and prefers lowland areas between the altitudes of 0 to 1,200 metres. It cannot stand frost. The exact origin is unknown; it is native to the tropical regions of the Americas and is widely propagated. It is an introduced species on all temperate continents, especially in subtropical regions.

Defense

The Memorial Sloan-Kettering Cancer Center cautions, "alkaloids extracted from graviola may cause neuronal dysfunction". Annonacin has been shown in laboratory research to be neurotoxic. In 2010, the French food safety agency, Agence française de sécurité sanitaire des produits de santé, concluded that "it is not possible to confirm that the observed cases of atypical Parkinson syndrome... are linked to the consumption of "Annona muricata"".

Uses

The flesh of the fruit consists of an edible, white pulp, 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. Due to the fruit's widespread cultivation, its derivative products are consumed in many countries like Mexico, Brazil, Venezuela, Colombia and Fiji. The seeds are normally left in the preparation, and removed while consuming, unless a blender is used for processing.

In Indonesia, "dodol sirsak", a sweet, is made by boiling soursop pulp in water and adding sugar until the mixture caramelizes and hardens. Soursop is also a common ingredient for making fresh fruit juices that are sold by street food vendors. In the Philippines, it is called "guyabano", derived from the Spanish "guanábana", and is eaten ripe, or used to make juices, smoothies, or ice cream. Sometimes, the leaf is used in tenderizing meat. In Vietnam, this fruit is called "mãng cầu Xiêm" in the south, or "mãng cầu" in the north, and is used to make smoothies, or eaten as is. In Cambodia, this fruit is called "tearb barung", literally "western custard-apple fruit." In Malaysia, it is known in Malay as "durian belanda" and in East Malaysia, specifically among the Dusun people of Sabah, it is locally known as "lampun". Popularly, it is eaten raw when it ripens, or used as one of the ingredients in "Ais Kacang" or "Ais Batu Campur". Usually the fruits are taken from the tree when they mature and left to ripen in a dark corner, whereafter they will be eaten when they are fully ripe. It has a white flower with a very pleasing scent, especially in the morning. While for people in Brunei Darussalam this fruit is popularly known as "Durian Salat", widely available and easily planted.

Soursop leaves are sold and consumed in Indonesia as herbal medicine. The leaves are usually boiled to make tea.