The sugar-apple or sweet-sop is the edible fruit of Annona squamosa,^[1] the most widely grown species of Annona and a native of tropical climate in the Americas and West Indies. Spanish traders aboard the Manila galleons docking in the Philippines brought it to Asia.^[2] The fruit is spherical-conical, 5–10 centimetres (2–4 inches) in diameter and 6–10 cm (2+1⁄4–4 in) long, and weighing 100–240 grams (3.5–8.5 ounces), with a thick rind composed of knobby segments. The color is typically pale green through blue-green, with a deep pink blush in certain varieties, and typically has a bloom. It is unique among Annona fruits in being segmented; the segments tend to separate when ripe, exposing the interior.

The flesh is fragrant and sweet, creamy white through light yellow, and resembles and tastes like custard. It is found adhering to 13-to-16-millimetre-long (1⁄2 to 5⁄8 in) seeds forming individual segments arranged in a single layer around a conical core. It is soft, slightly grainy, and slippery. The hard, shiny seeds may number 20–40 or more per fruit and have a brown to black coat, although varieties exist that are almost seedless.^[2][3] The seeds can be ground for use as an insecticide.^[1]

There are also new varieties being developed in Taiwan and Hong Kong. The atemoya or “pineapple sugar-apple”, a hybrid between the sugar-apple and the cherimoya, is popular in Taiwan, although it was first developed in the United States in 1908. The fruit is similar in sweetness to the sugar-apple but has a very different taste. As its name suggests, it tastes like pineapple.

Mammea africana is a medium to large sized tree within the family Calophyllaceae, it is also known as African mammee apple and its timber is traded under the trade name, Oboto. Mammea africana is found in evergreen and semi deciduous forests in West and Central Tropical Africa.^[1]

Description

A medium to large sized tree that can grow up to 40 meters tall with a dark green crown of short spreading branches, it has a cylindrical and straight trunk, that can be up to 27 meters tall without branches. Leaves are simple, coriaceous and thick, the upper surface is glossy dark green while beneath is less shiny and glabrous, the petiole is 0.4–1.5 cm long; leaf-blade is elliptical to oblong in outline, 12–26 cm long and 4–10 cm wide.^[2] Flower is axillary on leafy shoots and cauliflorous, with buds that are globular; pedicel is up to 4 cm long, petals are 4, white and caducous, up to 3 cm long.^[2] Fruit is a thick drupe, warty, up to 10 cm long, pale yellow in color, it has a coriaceous exocarp, while the mesocarp is juicy and fibrous, yellowish in color, the seed in the endocarp can be up to 65.7mm (2.6 inches) long and 48.7mm (1.9 inches) in thickness. but its most remarkable characteristic is that these seeds have no cotyledons (seed leaves) ^[3] [2]

Soursop (also called graviola, guyabano, and in Hispanic America, guanábana) is the fruit of Annona muricata, a broadleaf, flowering, evergreen tree.^[4][5] It is native to the tropical regions of the Americas and the Caribbean and is widely propagated.^[6] It is in the same genus, Annona, as cherimoya and is in the Annonaceae family.

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 to pineapple,^[5] the flavor of the fruit has been described as a combination of strawberries and apple with sour citrus flavor notes, contrasting with an underlying thick creamy texture reminiscent of banana.

Soursop is widely promoted (sometimes as “graviola”) as an alternative cancer treatment, but there is no reliable medical evidence it is effective for treating cancer or any disease.^[7]