The soursop is a native fruit of tropical North and South America. It belongs to the family Annonaceae which includes about 100 species of trees and shrubs. The soursop is among the four (4) best known species that produce edible fruits. The other species are sweetsop, custard apple and cherimoya. It is know by the name guanabana, corrosol, suirsaak and other in different tropical parts of the world
The soursop tree is a small evergreen usually growing from 5 to 9m (15 - 30 ft) high. The simple oval leaves are leathery, glossy and dark green in colour. They have a characteristic pungent odor when crushed.
In the last five (5) years (1995-2000), approximately, 1700 kg kg of soursop was exported from the island as fresh fruits to the United States of America, Canada and other Caribbean islands. In addition, small volumes are now being used in the fruit juice and puree industry in the making of ice cream and other frozen delicacies, also jams and jellies.
With the further growth of the Agro-industry and the new awareness of the consumer to the use of natural juices and their products, the demand for the soursop fruit has increased and therefore the need for the small farmers to improve their existing cultivation and increase the acreage under production.
Some segments contain oval, smooth, hard, black seeds which are toxic.
The soursop tree bears fruit continuously after 3-4 years of age with little care and produces several crops throughout the year.
The pulp is eaten as well as can be cut into bits and added to fruit cup or salads, or chilled and served as dessert with sugar and a little milk or cream.
Soursop drinks are very popular to all West Indians and Latin Americans.
In Dominican Republic, a soursop custard is made and a confection is also made by cooking soursop pulp in sugar syrup with cinnamon and lemon peel.
It is used in making ice cream and sherbets, jelly, tarts, syrup and nectar.
Immature fruits are cooked as vegetables or used in soup in Indonesia. Seeds are roasted or fried in Brazil.
The leaves are used as a tea to prevent high blood pressure, stomach disorders and for treatment of fevers.
The tea can also be used for cleaning floors and destroying fleas.
The seeds contain oil used for paint and as an insecticide.
Two characteristics that cause the soursop fruit to be highly perishable are:-
Its high rate of respiration, and
Its susceptibility to physical damage
The fruit is picked when fully developed and still firm but lack-lustre and may be slightly yellow-green in colour. In addition, optimum maturity is determined by the spacing of the spines on the surface of the fruit.
These spines become further and further apart as growth occurs. It has been found that when approximately 6-7 spines span 12 cm² , the fruit can be considered to be mature.
Fruits must be reaped early in the morning or late evening to prevent the build-up of field heat. Fruits are harvested using knives and then lowered to the ground. Soursor should never be knocked from the tree.
Fruits should not be allowed to ripen or become soft on the trees as they will fall and crush. The fruit must be handled with care to avoid bruising.
SORTING AND GRADING
All damaged fruits must be removed as these might become sources of ethylene gas which will increase the rate of ripening.
All immature fruits should also be removed as due to their high respiration rate will affect the rate of ripening of the mature fruits. Soursop can be graded based on shape and size to enhance packaging and presentation.
This is necessary due to the high respiration rate of the soursop fruit.
This process is necessary to:-
1)reduce rapidly the field heat, and
2)reduce the temperature of the fruit as quickly as possible to the required storage temperature. Hence the fruits should be removed immediately out of the field after being reaped.
Soursop should be collected carefully into shallow carton boxes or lined wooden boxes and baskets to prevent physical damage. Also the fruits should be separated from each other by use of soft material.
Be careful in the used of dried grass and banana leaves as these may contain pieces of sticks or prickles and insects which can damage the fruits.
The use of bags and sacks is prohibited as it results in bruising and mechanical damage to the fruits.
A mature fruit will store for a few days (2-3) at room temperature. This time is further enhanced if the fruits are stored on racks in a cool shed as the reduced temperature of the environment will reduce the rate of ripening.
All fruits should be:-
clean I.e. free from adhering soil, foreign matter or chemical residue;
Fresh I.e. no signs of shriveling
Firm and mature
Sound and without physical damage;
Free fro m insect damage.
Free from presence of insects eg. Scale insects.
To date none has been developed but all exporting fruits should meet the minimum requirements as well as (1) of uniform shape and size, (2) The stem should be attached and cut at the abscission point , about 2.5 cm long.
HANDLING PRACTICE IN PACKHOUSE
Fruits must be further graded to remove any damaged fruits.
Fruits must be lightly brushed to remove any insects or other extraneous matter.
Fruits should be packed in single layers into one piece or half telescopic fiber board cartons. Internal packaging is recommended to prevent fruit to fruit rubbing or puncturing.
Shredded paper or vertical dividers are used. Where staples are used in construction of the cartons, care should be taken to ensure complete staple closure.
Fruits should not be stored below 12°C as they are susceptible to chilling injury.
Signs of chilling injury are:-
Localised blackened, soft spots;
Dicolouration of the tissue (peel)
Failure to ripen normally when returned to ambient conditions.
This temperature provides a storage life of approximately 1-2 weeks.
Fruits should not be stored for over 24 hours either at ambient or cold temperature, prior to export, as:
1) At ambient, the fruits would have started to ripen and shrivel therefore reducing their saleability.
ii) at cold, as fruits are usually air freighted resulting in heavy condensation due to the warming up of the fruits and therefore creating the right environment for fungal development.
Proper preharvest and postharvest care of your produce will guarantee good market prices as our product is unique and will be able to compete on the overseas market.
GRADE RQUIREMENTS: for U.K., Holland, U.S.A. , and Canada
Small : 0.7 - 1.2kg (1.5 - 2. 5lbs.)
Medium : 1.2 - 2.0kg (2.5 - 4. 4lbs)
Large : 2.0 - 3.0kg (4.4 - 6.6lbs)
For more information contact:
Mrs. Janette Lawrence
Marketing Extension Unit
Str Line: 977-1151
Fax: 927-1592 or 970-4660