From the book
Fruits of Warm Climates
by Julia F. Morton
Soursop
Annona
muricata
ANNONACEAE
Of the 60 or more species of the genus Annona, family Annonaceae, the
soursop, A. muricata
L., is the most tropical, the largest-fruited, and the only one lending
itself well to preserving and processing.
Plate 10: SOURSOP, Annona
muricata
It
is generally known in most Spanish-speaking countries as guanabana; in
E1 Salvador, as guanaba; in Guatemala, as huanaba; in Mexico, often as
zopote de viejas, or cabeza de negro; in Venezuela, as catoche or
catuche; in Argentina, as anona de puntitas or anona de broquel; in
Bolivia, sinini; in Brazil, araticum do grande, graviola, or jaca do
Para; in the Netherlands Antilles, sorsaka or zunrzak, the latter name
also used in Surinam andJava; in French-speaking areas of the West
Indies, West Africa, and Southeast Asia, especially North Vietnam, it
is known as corossol, grand corossol, corossol epineux, or cachiman
epineux. In Malaya it may be called durian belanda, durian maki; or
seri kaya belanda; in Thailand, thu-rian-khack.
In 1951, Prof.
Clery Salazar, who was encouraging the development of soursop products
at the College of Agriculture at Mayaguez, Puerto Rico, told me that
they would like to adopt an English name more appealing than the word
"soursop", and not as likely as guanabana to be mispronounced. To date,
no alternatives have been chosen.
Fig. 20: Exceptionally large and well-formed
soursops (Annona muricata)
in a Saigon market, 1968.
Description
The
soursop tree is low-branching and bushy but slender because of its
upturned limbs, and reaches a height of 25 or 30 ft (7.5-9 m). Young
branchlets are rusty-hairy. The malodorous leaves, normally evergreen,
are alternate, smooth, glossy, dark green on the upper surface, lighter
beneath; oblong, elliptic or narrow obovate, pointed at both ends, 2
1/2 to 8 in (6.25-20 cm) long and 1 to 2 1/2 in (2.5-6.25 cm) wide. The
flowers, which are borne singly, may emerge anywhere on the trunk,
branches or twigs. They are short stalked, 1 1/2 to 2 in (4 5 cm) long,
plump, and triangular-conical, the 3 fleshy, slightly spreading, outer
petals yellow-green, the 3 close-set inner petals pale-yellow.
The
fruit is more or less oval or heart-shaped, some times irregular,
lopsided or curved, due to improper carper development or insect
injury. The size ranges from 4 to 12 in (10-30 cm) long and up to 6 in
(15 cm) in width, and the weight may be up to 10 or 15 lbs (4.5-6.8
kg). The fruit is compound and covered with a reticulated,
leathery-appearing but tender, inedible, bitter skin from which
protrude few or many stubby, or more elongated and curved, soft,
pliable "spines". The tips break off easily when the fruit is fully
ripe. The skin is dark-green in the immature fruit, becoming slightly
yellowish-green before the mature fruit is soft to the touch. Its inner
surface is cream-colored and granular and separates easily from the
mass of snow-white, fibrous, juicy segments—much like flakes
of
raw fish—surrounding the central, soft-pithy core. In aroma,
the
pulp is somewhat pineapple-like, but its musky, subacid to acid flavor
is unique. Most of the closely-packed segments are seedless. In each
fertile segment there is a single oval, smooth, hard, black seed, l/2
to 3/4 in (1.25-2 cm) long; and a large fruit may contain from a few
dozen to 200 or more seeds.
Origin and
Distribution
Oviedo,
in 1526, described the soursop as abundant in the West Indies and in
northern South America. It is today found in Bermuda and the Bahamas,
and both wild and cultivated, from sea-level to an altitude of 3,500 ft
(1,150 m) throughout the West Indies and from southern Mexico to Peru
and Argentina. It was one of the first fruit trees carried from America
to the Old World Tropics where it has become widely distributed from
southeastern China to Australia and the warm lowlands of eastern and
western Africa. It is common in the markets of Malaya and southeast
Asia. Very large, symmetrical fruits have been seen on sale in South
Vietnam. It became well established at an early date in the Pacific
Islands. The tree has been raised successfully but has never fruited in
Israel.
In Florida, the soursop has been grown to a limited
extent for possibly 110 years. Sturtevant noted that it was not
included by Atwood among Florida fruits in 1867 but was listed by the
American Pomological Society in 1879. A tree fruited at the home of
John Fogarty of Manatee before the freeze of 1886. In the southeastern
part of the state and especially on the Florida Keys, it is often
planted in home gardens.
In regions where sweet fruits are
preferred, as in South India and Guam, the soursop has not enjoyed
great popularity. It is grown only to a limited extent in Madras.
However, in the East Indies it has been acclaimed one of the best local
fruits. In Honolulu, the fruit is occasionally sold but the demand
exceeds the supply. The soursop is one of the most abundant fruits in
the Dominican Republic and one of the most popular in Cuba, Puerto
Rico, the Bahamas, Colombia and northeastern Brazil.
In 1887,
Cuban soursops were selling in Key West, Florida, at 10 to 50 cents
apiece. In 1920, Wilson Popenoe wrote that: "In the large cities of
tropical America, there is a good demand for the fruits at all times of
the year, a demand which is not adequately met at present." The island
of Grenada produces particularly large and perfect soursops and
regularly delivers them by boat to the market of Port-of Spain because
of the shortage in Trinidad. In Colombia, where the soursop is
generally large, well-formed and of high quality, this is one of the 14
tropical fruits recommended by the Instituto Latinoamericano de
Mercadeo Agricola for large-scale planting and marketing. Soursops
produced in small plots, none over 5 acres (2.27 ha), throughout
Venezuela supply the processing plants where the frozen concentrate is
packed in 6 oz (170 g) cans. In 1968, 2,266 tons (936 MT) of juice were
processed in Venezuela. The strained pulp is also preserved
commercially in Costa Rica. There are a few commercial soursop
plantations near the south coast of Puerto Rico and several processing
factories. In 1977, the Puerto Rican crop totaled 219,538 lbs (99,790
kg).
At the First International Congress of Agricultural and
Food Industries of the Tropical and Subtropical Zones, held in 1964,
scientists from the Research Laboratories of Nestle Products in Vevey,
Switzerland, presented an evaluation of lesser-known tropical fruits
and cited the soursop, the guava and passionfruit as the 3 most
promising for the European market, because of their distinctive
aromatic qualities and their suitability for processing in the form of
preserved pulp, nectar and jelly.
Varieties
In
Puerto Rico, the wide range of forms and types of seedling soursops are
roughly divided into 3 general classifications: sweet, subacid, and
acid; then subdivided as round, heart-shaped, oblong or angular; and
finally classed according to flesh consistency which varies from soft
and juicy to firm and comparatively dry. The University of Puerto
Rico's Agricultural Experiment Station at one time cataloged 14
different types of soursops in an area between Aibonito and Coamo. In
El Salvador, 2 types of soursops are distinguished: guanaba azucaron
(sweet) eaten raw and used for drinks; and guanaba acida (very sour),
used only for drinks. In the Dominican Republic, the guanabana dulce
(sweet soursop) is most sought after. The term "sweet" is used in a
relative sense to indicate low acidity. A medium-sized, yellow-green
soursop called guanabana sin fibre (fiberless) has been vegetatively
propagated at the Agricultural Experiment Station at Santiago de las
Vegas, Cuba. The foliage of this superior clone is distinctly
bluish-green. In 1920, Dr. Wilson Popenoe sent to the United States
Department of Agriculture, from Costa Rica, budwood of a soursop he
named 'Bennett' in honor of G.S. Bennett, Agricultural Superintendent
of the Costa Rican Division of the United Fruit Company. He described
the fruit as large and handsome (as shown in the photograph
accompanying the introduction record No. 51050) and he declared the
tree to be the most productive he had seen.
Fig.
21: The soursop tree may bear fruits anywhere on its trunk or branches.
Multiple-stems of this tree are the result of its having been frozen to
the ground more than once.
Climate
The
soursop is truly tropical. Young trees in exposed places in southem
Florida are killed by only a few degrees of frost. The trees that
survive to fruiting age on the mainland are in protected situations,
close to the south side of a house and sometimes near a source of heat.
Even so, there will be temporary defoliation and interruption of
fruiting when the temperature drops to near freezing. In Key West,
where the tropical breadfruit thrives, the soursop is perfectly at
home. In Puerto Rico, the tree is said to prefer an altitude between
800 and 1,000 ft (244300 m), with moderate humidity, plenty of sun and
shelter from strong winds.
Soil
Best
growth is achieved in deep, rich, well-drained, semi-drysoil, but the
soursop tree can be and is commonly grown in acid and sandy soil, and
in the porous, oolitic limestone of South Florida and the Bahama
Islands.
Propagation
The
soursop is usually grown from seeds. They should be sown in flats or
containers and kept moist and shaded. Germination takes from 15 to 30
days. Selected types can be reproduced by cuttings or by
shield-budding. Soursop seedlings are generally the best stock for
propagation, though grafting onto custard apple (Annona reticulata),
the mountain soursop (A.
montana), or pond apple (A. glabra), is
usually successful. The pond apple has a dwarfing effect. Grafts on
sugar apple (A. squamosa)
and cherimoya (A.
cherimola) do not live for long, despite the fact that the
soursop is a satisfactory rootstock for sugar apple in Ceylon and India.
Culture
In
ordinary practice, seedlings, when 1 ft (30 cm) or more in height are
set out in the field at the beginning of the rainy season and spaced 12
to 15 ft (3.65-4.5 m) apart, though 25 ft (7.5 m) each way has been
suggested. A spacing of 20 x 25 ft (6x7.5 m) allows 87 trees per acre
(215/ha). Close-spacing, 8 x 8 ft (2.4x2.4 m) is thought aufficient for
small gardens in Puerto Rico. The tree grows rapidly and begins to bear
in 3 to 5 years. In Queensland, well-watered trees have attained 15 to
18 ft (4.5-5.5 m) in 6 to 7 years. Mulching is recommended to avoid
dehydration of the shallow, fibrous root system during dry, hot
weather. If in too dry a situation, the tree will cast off all of its
old leaves before new ones appear. A fertilizer mixture containing 10%
phosphoric acid, 10% potash and 3% nitrogen has been advocated in Cuba
and Queensland. But excellent results have been obtained in Hawaii with
quarterly applications of 10-10-10 N P K—½ lb (.225 kg) per
tree the first year, 1 lb (.45 kg)/tree the 2nd year, 3 lbs (1.36
kg)/tree the 3rd year and thereafter.
Season
The
soursop tends to flower and fruit more or less continuously, but in
every growing area there is a principal season of ripening. In Puerto
Rico, this is from March to June or September; in Queensland, it begins
in April; in southern India, Mexico and Florida, it extends from June
to September; in the Bahamas, it continues through October. In Hawaii,
the early crop occurs from January to April; midseason crop, June to
August, with peak in July; and there is a late crop in October or
November.
Harvesting
The
fruit is picked when full grown and still firm but slightly
yellow-green. If allowed to soften on the tree, it will fall and crush.
It is easily bruised and punctured and must be handled with care. Firm
fruits are held a few days at room temperature. When eating ripe, they
are soft enough to yield to the slight pressure of one's thumb. Having
reached this stage, the fruit can be held 2 or 3 days longer in a
refrigerator. The skin will blacken and become unsightly while the
flesh is still unspoiled and usable. Studies of the ripening process in
Hawaii have determined that the optimum stage for eating is 5 to 6 days
after harvest, at the peak of ethylene production. Thereafter, the
flavor is less pronounced and a faint off odor develops. In Venezuela,
the chief handicap in commercial processing is that the fruits stored
on racks in a cool shed must be gone over every day to select those
that are ripe and ready for juice extraction.
Yield
The
soursop, unfortunately, is a shy-bearer, the usual crop being 12 to 20
or 24 fruits per tree. In Puerto Rico, production of 5,000 to 8,000 lbs
per acre (roughly equal kg/ha), is considered a good yield from
well-cared-for trees. A study of the first crop of 35 5 year-old trees
in Hawaii showed an average of 93.6 lbs (42.5 kg) of fruits per tree.
Yield was slightly lower the 2nd year. The 3rd year, the average yield
was 172 lbs (78 kg) per tree. At this rate, the annual crop would be
16,000 lbs per acre (roughly equal kg/ha).
Pests
& Diseases
Queensland's
principal soursop pest is the mealybug which may occur in masses on the
fruits. The mealybug is a common pest also in Florida, where the tree
is often infested with scale insects. Sometimes it may be infected by a
lace-wing bug.
The fruit is subject to attack by fruit flies—Anastrepha suspensa,
A. striata
and Ceratitis capitata.
Red spiders are a problem in dry climates.
Dominguez
Gil (1978 and 1983), presents an extensive list of pests of the soursop
in the State of Zulia, Venezuela. The 5 most damaging are: 1) the wasp,
Bephratelloides (Bephrata)
maculicollis,
the larvae of which live in the seeds and emerge from the fully-grown
ripe fruit, leaving it perforated and highly perishable; 2) the moth, Cerconota (Stenoma) anonella,
which lays its eggs in the very young fruit causing stunting and
malformation; 3) Corythucha
gossipii; which attacks the leaves; 4) Cratosomus inaequalis,
which bores into the fruit, branches and trunk; 5) Laspeyresia sp.,
which perforates the flowers. The first 3 are among the 7 major pests
of the soursop in Colombia, the other 4 being: Toxoptera aurantii;
which affects shoots, young leaves, flowers and fruits; present but not
important in Venezuela; Aphis
spiraecola; Empoasca
sp., attacking the leaves; and Aconophora
concolor, damaging the flowers and fruits. Important
beneficial agents preying on aphids are Aphidius testataceipes,
Chrysopa
sp., and Curinus
sp. Lesser enemies of the soursop in South America include: Talponia backeri
and T. batesi
which damage flowers and fruits; Horiola
picta and H.
lineolata, feeding on flowers and young branches; Membracis foliata,
attacking young branches, flower stalks and fruits; Saissetia nigra; Escama ovalada, on
branches, flowers and fruits; Cratosomus
bombina, a fruit borer; and Cyclocephala signata,
affecting the flowers.
In Trinidad, the damage done to soursop flowers by Thecla ortygnus
seriously limits the cultivation of this fruit. The sphinx caterpillar,
Cocytius
antueus may be found feeding on soursop leaves in
Puerto Rico. Bagging of soursops is necessary to protect them from Cerconota anonella.
However, one grower in the Magdalena Valley of Colombia claims that
bagged fruits are more acid than others and the flowers have to be
handpollinated.
It has been observed in Venezuela and El
Salvador that soursop trees in very humid areas often grow well but
bear only a few fruits, usually of poor quality, which are apt to rot
at the tip. Most of their flowers and young fruits fall because of
anthracnose caused by Collectotrichum
gloeosporioides.
It has been said that soursop trees for cultivation near San Juan,
Puerto Rico, should be seedlings of trees from similarly humid areas
which have greater resistance to anthracnose than seedlings from dry
zones. The same fungus causes damping-off of seedlings and die-back of
twigs and branches.
Occasionally the fungus, Scolecotrichum
sp. ruins the leaves in Venezuela. In the East Indies, soursop trees
are sometimes subject to the root-fungi, Fomes lamaoensis
and Diplodia
sp. and by pink disease due to Corticum
salmonicolor.
Fig. 22: Canned soursop concentrate is produced in Venezuela. On the
branch at the right is a soursop flower.
Food Uses
Soursops
of least acid flavor and least fibrous consistency are cut in sections
and the flesh eaten with a spoon. The seeded pulp may be torn or cut
into bits and added to fruit cups or salads, or chilled and served as
dessert with sugar and a little milk or cream. For years, seeded
soursop has been canned in Mexico and served in Mexican restaurants in
New York and other northern cities.
Most widespread throughout
the tropics is the making of refreshing soursop drinks (called champola
in Brazil; carato in Puerto Rico). For this purpose, the seeded pulp
may be pressed in a colander or sieve or squeezed in cheesecloth to
extract the rich, creamy juice, which is then beaten with milk or water
and sweetened. Or the seeded pulp may be blended with an equal amount
of boiling water and then strained and sweetened. If an electric
blender is to be used, one must first be careful to remove all the
seeds, since they are somewhat toxic and none should be accidentally
ground up in the juice.
In Puerto Rican processing factories,
the hand-peeled and cored fruits are passed through a mechanical pulper
having nylon brushes that press the pulp through a screen, separating
it from the seeds and fiber. A soursop soft drink, containing 12 to 15%
pulp, is canned in Puerto Rico and keeps well for a year or more. The
juice is prepared as a carbonated bottled beverage in Guatemala, and a
fermented, cider-like drink is sometimes made in the West Indies. The
vacuum-concentrated juice is canned commercially in the Philippines.
There soursop drinks are popular but the normal "milk" color is not.
The people usually add pink or green food coloring to make the drinks
more attractive. The strained pulp is said to be a delicacy mixed with
wine or brandy and seasoned with nutmeg. Soursop juice, thickened with
a little gelatin, makes an agreeable dessert.
In the Dominican
Republic, a soursop custard is enjoyed and a confection is made by
cooking soursop pulp in sugar sirup with cinnamon and lemon peel.
Soursop ice cream is commonly frozen in refrigerator ice-cube trays in
warm countries.
In the Bahamas, it is simply made by mashing the
pulp in water, letting it stand, then straining to remove fibrous
material and seeds. The liquid is then blended with sweetened condensed
milk, poured into the trays and stirred several times while freezing. A
richer product is made by the usual method of preparing an ice cream
mix and adding strained soursop pulp just before freezing. Some Key
West restaurants have always served soursop ice cream and now the
influx of residents from the Caribbean and Latin American countries has
created a strong demand for it. The canned pulp is imported from
Central America and Puerto Rico and used in making ice cream and
sherbet commercially. The pulp is used, too, for making tarts and
jelly, sirup and nectar. The sirup has been bottled in Puerto Rico for
local use and export. The nectar is canned in Colombia and frozen in
Puerto Rico and is prepared fresh and sold in paper cartons in the
Netherlands Antilles. The strained, frozen pulp is sold in plastic bags
in Philippine supermarkets.
Immature soursops are cooked as
vegetables or used in soup in Indonesia. They are roasted or fried in
northeastern Brazil. I have boiled the half-grown fruit whole, without
peeling. In an hour, the fruit is tender, its flesh off-white and
mealy, with the aroma and flavor of roasted ears of green corn (maize).
| Food
Value Per
100 g of Edible Portion* |
| Calories |
61.3-53.1 |
| Moisture |
82.8g |
| Protein |
1.00g |
| Fat |
0.97g |
| Carbohydrates |
14.63g |
| Fiber |
0.79g |
| Ash |
60g |
| Calcium |
10.3
mg |
| Phosphorus |
27.7
mg |
| Iron |
0.64
mg |
| Vitamin
A (B-carotene) |
0 |
| Thiamine
|
0.11
mg |
| Riboflavin |
0.05
mg |
| Niacin |
1.28mg |
| Ascorbic
Acid |
29.6
mg |
Amino
Acids: |
|
| Tryptophan |
11
mg |
| Methionine |
7
mg |
| Lysine |
60mg |
*Analyses made at the Laboratorio FIM de Nutricion, Havana, Cuba. |
|
Toxicity
The
presence of the alkaloids anonaine and anoniine has been reported in
this species. The alkaloids muricine, C19H21O4N (possibly
des-N-methylisocorydine or des-N methylcorydine) and muricinine,
C18H19O4 (possibly des-N-methylcorytuberine), are found in the bark.
Muricinine is believed to be identical to reticuline. An unnamed
alkaloid occurs in the leaves and seeds. The bark is high in
hydrocyanic acid. Only small amounts are found in the leaves and roots
and a trace in the fruit. The seeds contain 45% of a yellow non-drying
oil which is an irritant poison, causing severe eye inflamation.
Other Uses
Fruit:
In the Virgin Islands, the fruit is placed as a bait in fish
traps.
Seeds:
When pulverized, the seeds are effective pesticides against head lice,
southern army worms and pea aphids and petroleum ether and chloroform
extracts are toxic to black carpet beetle larvae. The seed oil kills
head lice.
Leaves:
The leaf decoction is lethal to head lice and bedbugs.
Bark:
The bark of the tree has been used in tanning. The bark fiber is strong
but, since fruiting trees are not expendable, is resorted to only in
necessity. Bark, as well as seeds and roots, has been used as fish
poison.
Wood:
The wood is pale, aromatic, soft, light in weight
and not durable. It has been used for ox yokes because it does not
cause hair loss on the neck.
In Colombia, it is deemed to be
suitable for pipestems and barrel staves. Analyses in Brazil show
cellulose content of 65 to 76%, high enough to be a potential source of
paper pulp.
Medicinal Uses:
The juice of the ripe fruit is said
to be diuretic and a remedy for haematuria and urethritis. Taken when
fasting, it is believed to relieve liver ailments and leprosy.
Pulverized immature fruits, which are very astringent, are decocted as
a dysentery remedy. To draw out chiggers and speed healing, the flesh
of an acid soursop is applied as a poultice unchanged for 3 days.
In
Materia Medica of British Guiana, we are told to break soursop leaves
in water, "squeeze a couple of limes therein, get a drunken man and rub
his head well with the leaves and water and give him a little of the
water to drink and he gets as sober as a judge in no time." This
sobering or tranquilizing formula may not have been widely tested, but
soursop leaves are regarded throughout the West Indies as having
sedative or soporific properties. In the Netherlands Antilles, the
leaves are put into one's pillowslip or strewn on the bed to promote a
good night's sleep. An infusion of the leaves is commonly taken
internally for the same purpose. It is taken as an analgesic and
antispasmodic in Esmeraldas Province, Ecuador. In Africa, it is given
to children with fever and they are also bathed lightly with it. A
decoction of the young shoots or leaves is regarded in the West Indies
as a remedy for gall bladder trouble, as well as coughs, catarrh,
diarrhea, dysentery and indigestion; is said to "cool the blood," and
to be able to stop vomiting and aid delivery in childbirth. The
decoction is also employed in wet compresses on inflammations and
swollen feet. The chewed leaves, mixed with saliva, are applied to
incisions after surgery, causing proud flesh to disappear without
leaving a scar. Mashed leaves are used as a poultice to alleviate
eczema and other skin afflictions and rheumatism, and the sap of young
leaves is put on skin eruptions.
The roots of the tree are
employed as a vermifuge and the root bark as an antidote for poisoning.
A tincture of the powdered seeds and bay rum is a strong emetic.
Soursop flowers are believed to alleviate catarrh.
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