Cherimoya
The cherimoya ("Annona cherimola"), also spelled chirimoya and called chirimuya by the Inca people, is a species of edible fruit-bearing plant in the genus "Annona", from the family Annonaceae, which includes the closely related sweetsop and soursop. The plant has long been believed to be native to Ecuador and Peru, with cultivation practiced in the Andes and Central America, although a recent hypothesis postulates Central America as the origin instead, because many of the plant's wild relatives occur in this area. Cherimoya is grown in tropical and subtropical regions throughout the world including Central America, eastern South  America, Southern California, South Asia, Australia, the Mediterranean region and North Africa. American writer Mark Twain called the cherimoya "the most delicious fruit known to men". The creamy texture of the flesh gives the fruit its secondary name, the custard apple. Etymology. The name is derived from the Quechua word "chirimuya", which means "cold seeds". The plant grows at high altitudes, where the weather is colder, and the seeds will germinate at higher altitudes. In Bolivia, Peru, Chile, Ecuador, Venezuela and Colombia, the fruit is commonly known as "chirimoya" (spelled according to the rules of the Spanish language). Description. "Annona  cherimola" is a fairly dense, fast-growing, woody, briefly deciduous but mostly evergreen, low-branched, spreading tree or shrub, tall. Mature branches are sappy and woody. Young branches and twigs have a matting of short, fine, rust-colored hairs. The leathery leaves are long wide, and mostly elliptic, pointed at the ends and rounded near the leaf stalk. When young, they are covered with soft, fine, tangled, rust-colored hairs. When mature, the leaves bear hairs only along the veins on the undersurface. The tops are hairless and a dull medium green with paler veins, the backs are velvety, dull  grey-green with raised pale green veins. New leaves are whitish below. Leaves are single and alternate, dark green, and slightly hairy on the top surface. They attach to branches with stout long and densely hairy leaf stalks. Cherimoya trees bear very pale green, fleshy flowers. They are long with a very strong fruity odor. Each flower has three outer, greenish, fleshy, oblong, downy petals and three smaller, pinkish inner petals with yellow or brown finely matted hairs outside, whitish with purple spots and many stamens on the inside. Flowers appear on the branches opposite to the leaves, solitary or  in pairs or groups of three, on flower stalks that are covered densely with fine rust-colored hairs, long. Buds are long and wide at the base. The pollen is shed as permanent tetrads. Fruits. The edible cherimoya fruit is a large, green, conical or heart-shaped compound fruit, long, with diameters of , and skin that gives the appearance of having overlapping scales or knobby warts. They ripen to brown with a fissured surface in late winter and early spring; they weigh on the average , but extra large specimens may weigh or more. Cherimoya fruits are commercially classified according to  degree of surface irregularity, as follows: "Lisa", almost smooth, difficult to discern areoles; "Impresa", with "fingerprint" depressions; "Umbonata", with rounded protrusions at the apex of each areole; "Mamilata" with fleshy, nipple-like protrusions; or "Tuberculata", with conical protrusions having wart-like tips. The flesh of the cherimoya contains numerous hard, inedible, black, bean-like, glossy seeds, long and about half as wide. Cherimoya seeds are poisonous if crushed open. Like other members of the family Annonaceae, the entire plant contains small amounts of neurotoxic acetogenins, such as annonacin, which appear to be linked to atypical parkinsonism in Guadeloupe. Moreover, an  extract of the bark can induce paralysis if injected. Distribution and habitat. Widely cultivated now, "Annona cherimola" is believed to have originated in the Andes of South America at altitudes of , although an alternative hypothesis postulates Central America as the origin instead, because many of the plant's wild relatives occur in this area. From there it was taken by Europeans to various parts of the tropics. Unlike other "Annona" species, "A. cherimola" has not successfully naturalized in West Africa, and "Annona glabra" is often misidentified as this species in Australasia. Australia Ecology. Pollination. The flowers of "A. cherimola" are  hermaphroditic and have a mechanism to avoid self-pollination. The short-lived flowers open as female, then progress to a later, male stage in a matter of hours. This requires a separate pollinator that not only can collect the pollen from flowers in the male stage, but also deposit it in flowers in the female stage. Studies of which insect(s) serve as the natural pollinator in the cherimoya's native region have been inconclusive; some form of beetle is suspected. Quite often, the female flower is receptive in the early part of the first day, but pollen is not produced  in the male stage until the late afternoon of the second day. Honey bees are not good pollinators of this plant, for example, because their bodies are too large to fit between the fleshy petals of the female flower. Female flowers have the petals only partially separated, and the petals separate widely when they become male flowers. So, the bees pick up pollen from the male flowers, but are unable to transfer this pollen to the female flowers. The small beetles which are suspected to pollinate cherimoya in its land of origin must therefore be much smaller than bees. For  fruit production outside the cherimoya's native region, cultivators must either rely upon the wind to spread pollen in dense orchards or else use hand pollination. Pollinating by hand requires a paint brush. Briefly, to increase fruit production, growers collect the pollen from the male plants with the brush, and then transfer it to the female flowers immediately or store it in the refrigerator overnight. Cherimoya pollen has a short life, but it can be extended with refrigeration. Climate requirements. The evaluation of 20 locations in Loja Province, Ecuador, indicated certain growing preferences of wild cherimoya, including altitude between , optimum  annual temperature range between , annual precipitation between , and soils with high sand content and slightly acidic properties with pH between 5 and 6.5. In Western horticulture, growers are often advised to grow cherimoya in full sun, while the plant has been considered shade-tolerant in Japan. In 2001, a study conducted by Kyoto University showed shading of 50–70% sunlight was adequate to obtain an optimal light environment. Cultivation. Cultivars. The cherimoya of the Granada-Málaga tropical coast in Spain is a fruit of the cultivar 'Fino de Jete' with the EU's protected designation of origin appellation. 'Fino de Jete ' fruits have skin type Impressa and are smooth or slightly concave at the edges. The fruit is round, oval, heart-shaped, or kidney-shaped. The seeds are enclosed in the carpels and so do not detach easily. The flavour balances intense sweetness with slight acidity and the soluble sugar content exceeds 17° Bx. This variety is prepared and packed in the geographical area because "it is a very delicate perishable fruit and its skin is very susceptible to browning caused by mechanical damage, such as rubbing, knocks, etc. The fruit must be handled with extreme care, from picking by  hand in the field to packing in the warehouse, which must be carried out within 24 hours. Repacking or further handling is strictly forbidden." "Annona cherimola", preferring the cool Andean altitudes, readily hybridizes with other "Annona" species. A hybrid with "A. squamosa" called atemoya has received some attention in West Africa, Australia, Brazil, and Florida. Propagation. The tree thrives throughout the tropics at altitudes of . Though sensitive to frost, it must have periods of cool temperatures or the tree will gradually go dormant. The indigenous inhabitants of the Andes say the cherimoya cannot tolerate snow. In the Mediterranean region , it is cultivated mainly in southern Spain and Portugal, where it was introduced between 1751 and 1797, after which it was carried to Italy, but now can also be found in several countries of Africa, the Middle East, and Oceania. It is cultivated throughout the Americas, including Hawaii since 1790 and California, where it was introduced in 1871. Harvest. Large fruits which are uniformly green, without cracks or mostly browned skin, are best. The optimum temperature for storage is , depending on cultivar, ripeness stage, and duration, with an optimum relative humidity of 90–95%. Unripe cherimoyas will ripen at room temperature , when they will yield to gentle pressure. Exposure to ethylene (100 ppm for one to two days) accelerates ripening of mature green cherimoya and other "Annona" fruits; they can ripen in about five days if kept at . Ethylene removal can also be helpful in slowing the ripening of mature green fruits. Nutritional profile. Raw cherimoya fruit is 79% water, 18% carbohydrate, 2% protein, and 1% fat (table). In a 100-gram reference amount providing 75 calories, cherimoya is a rich source (20% or more of the Daily Value, DV) of vitamin B6 and a moderate source (10–19% DV) of vitamin  C, dietary fiber, and riboflavin (table). Eating quality. "The pineapple, the mangosteen, and the cherimoya", wrote the botanist Berthold Carl Seemann, "are considered the finest fruits in the world, and I have tasted them in those localities where they are supposed to attain their highest perfection – the pineapple in Guayaquil, the mangosteen in the Indian Archipelago, and the cherimoya on the slopes of the Andes, and if I were asked which would be the best fruit, I would choose without hesitation, cherimoya. Its taste, indeed, surpasses that of every other fruit, and Haenke was quite right when he called it  the masterpiece of Nature." Fruits require storage at to inhibit softening and maintain eating quality. Different varieties have different flavors, textures, and shapes. The flavor of the flesh ranges from mellow sweet to tangy or acidic sweet, with variable suggestions of pineapple, banana, pear, papaya, strawberry or other berry, and apple, depending on the variety. The ripened flesh is creamy white. When ripe, the skin is green and gives slightly to pressure. Some characterize the fruit flavor as a blend of banana, pineapple, papaya, peach, and strawberry. The fruit can be chilled and eaten with a spoon, which has earned  it another nickname, the "ice cream fruit". In Peru and Chile, it is commonly used in ice creams and yogurt. When the fruit is ripe and still has the fresh, fully mature green-yellow skin color, the texture is like that of a soft-ripe pear and papaya. When the skin turns brown at room temperature, the fruit is no longer good for human consumption. Culture. The Moche culture of Peru had a fascination with agriculture and represented fruits and vegetables in their art; cherimoyas were often depicted in their ceramics.