Mango Crop Guides
Postharvest Handling of Mango
The following is excerpted from "Product Specifications and Postharvest Handling for Fruits,
Vegetables and Root Crops Exported from the Caribbean", by Dr. A. Medlicott (Fintrac).
Unauthorized duplication is prohibited.
MangoManfifera indica L.
 Ceylon
Mango Packed for Export
Chief Producers
Jamaica, Grenada, St. Lucia, Dominica, St. Vincent, Belize
Season
April to September
Quality Criteria
Market requirements state that mangoes on arrival should be:
- Physiologically mature;
- Commencing ripening with 30 to 50% coloration;
- Significant area of red colour on the fruit shoulders;
- Relatively firm;
- Minimum sugar content of 10%;
- Uniform shape;
- Free from disease, decay, sunscald, cracks, bruises, latex stains, insect and mechanical
damage;
-
- Conform to the weight and size specifications;
Volume sales of mangoes are based on presence of the red color, acceptable stage of ripeness for
consumption, uniform size grading, uniform stages of ripeness and the absence of disease or
damage.
Variety
Julie, Graham, Grenada, Peach
POST-HARVEST HANDLING SYSTEM
Mangoes can be successfully stored for up to three weeks if the recommended harvest maturity,
post-harvest handling and storage conditions are employed.
Harvest Maturity
All mangoes to be exported by air should be harvested in the physiologically mature, hard, green
condition. Harvest maturity in most varieties can Rejudged by the position of the shoulders in
relation to the position of the stem (see below). Half-mature fruits may be included in the
shipment, but should not make up more than 25% of the total. Fruit harvested in the ripe
condition or with more than 15% yellow coloration, should be selected in the field and not
included In export shipments. Ripe fruits are highly susceptible to bruising and mechanical
damage during handling and transport. Immature fruits should not be shipped.
For mangoes exported by sea, the optimum stage of harvest maturity is the "half-mature" stage.
Fruit should not show any signs of softening or degreening, yellow colour development).
Immature fruit should not be shipped.
Assessment of Harvest Maturity in Mangoes
The following descriptions are appropriate for Julie and Graham mangoes and for other varieties
which show similar morphological characteristics:
- Fully mature: outgrown shoulders, formation of a depression with ridges at the stem end,
firm and green;
- Half-mature: shoulders in line with the stem with slightly ridged edges, firm and green;
- Immature: shoulders below the stem insertion with ridges absent, firm and green;
Harvesting
Where possible, mangoes should be harvested by hand from the ground, by snapping the mango
from the stem. Fully mature fruit will detach easily, whereas half-mature fruit will not. Optimum
harvesting involves using secateurs and cutting the stem 1 - 2 cm away from the fruit (this
technique reduces latex exudation and staining and reduces the possibility of entrance of fungal
organisms). Where harvesting by hand from the ground is not possible, harvesting implements
should be used. The most suitable involves a long pole with a cutting blade and a small bag
under the blade to catch the fruit. Alternatively, climbers may use cotton bags which are filled
are lowered to the floor. Mangoes should never be knocked from the tree, dropped or thrown to
the ground. Outgrading should be carried out in the held to remove immature, undersized,
damaged, bruised, scarred or ripe fruit. The fruit on any one tree are of different ages because
flowering and pollination occurs over a period of several weeks. Therefore, all the fruits do not
mature simultaneously. Fruit are usually harvested from individual trees on several occasions
throughout the season.
 Mango
anthracnose
After harvest, latex should be allowed to drain away from the fruit and the fruit placed in plastic
field crates. Bags, sacks and buckets are to be avoided as these generally result in mechanical
damage and bruising. Harvested mangoes should not be left in direct sunlight, wind or rain,
either in the field or during transport from the field to the packing facility. On arrival in the
packing area, the mangoes should be graded for removal of immature, under-sized, damaged,
bruised, scarred or ripe fruit. Acceptable fruit should be placed in water (containing 100 ppm
sodium hyperchlorite) for washing to remove debris and latex stains. Mangoes harvested from
areas or trees which are known to suffer from anthracnose or for fruit destined for long term
storage, treatment is required in a hot water bath (550øC for 5 minutes) containing 0.05% Thiabendazole. This technique shows good control of anthracnose, but generally requires the use of specialized equipment, as temperature control of the water bath is essential for the
effectiveness and prevention of fruit damage.
After fungicide treatment, the fruit should be allowed to cool and dry in preparation for grading
and packing.
Export Grading and Packing
The fruits should be checked prior to packing to ensure the absence of blemishes, bruises, insect
and mechanical damage. Fruits should be graded in each carton according to the variety, size
(giving a range of Counts" for each shipment) and maturity (firm green full-mature and
half-mature fruits will ripen at different rates and should not be packed in the same carton).
Minimum weight and size specifications are given in the specification section below. When
packing, the fruits should be placed leaning to the side rather then directly on the base. Net
weight requirements are 4 to 5 kg depending on the carton and the market destination. Cartons
must not be over-filled during packing.
Packaging
Mangoes should be packed in single layer one- or two-piece full-telescopic, self-locking
flbreboard cartons; bursting strength requirements 250 - 275 lb/in2. Ventilation and handle holes
are recommended to provide adequate ventilation and ease of handling. Carton labeling
requirements for the individual markets should be followed. A layer of shredded paper in the
base of the carton is recommended, as this will assist in cushioning the fruits. Each alternate
mango in a carton should be wrapped in a tissue to reduce fruit to fruit rubbing; small identity
labels attached to alternate fruit will assist in product presentation.
Carton internal dimensions:
- 10.9 by 34 by 26.9 cm (4.3" by 13.4" by 10.6")
- 10.2.by 43.2 by 27.9cm (4"by l7" by 11")
Unitization
Palletisation is essential to minimize fruit damage due to multiple handling. Movement of fruit
within packhouses or during temporary storage can be aided by palletisation. For sea-shipment
exports of mangoes, palletisation is a necessity.
Pre-cooling
If mangoes are to be exported to the destination within two to three days of harvesting, as with
air-shipments, then pre-cooling is advisable but not essential. Mangoes transported by sea should
be precooled prior to loading into containers or holds. Several methods of pre-cooling are
available, and the system adopted should suit the specific requirements and capabilities.
Temperature controlled rooms are the most simple, although cooling may be slow if stacking
and spacing are not adequate to allow free and even air flow or if the refrigeration capacity is
low. A forced air system is more efficient, although this requires a specially designed unit and
compatible packaging. Mangoes should be cooled to a minimum of 12øC.
Storage and Ripening
For export of mangoes by air, storage or ripening may be required prior to shipment.
Ripening: - Recommendations for the optimum temperature for ripening of mangoes
vary according to the variety and the origin, although the range of 20ø to 25øC is usually
optimum. Higher temperatures of 25ø to 30øC may result in ripe fruit with off-flavours and
mottling of the peel. Initiation and synchronisation of ripening and a shortening of the ripening
period of mangoes can be achieved with exposure to ethylene gas, either direct from cylinders or
as liberated from ethephon when utilized with a catalytic generator. Acetylene gas liberated from
calcium carbide exhibits a similar effect. Treatment with gases are carried out in air-tight room
for 24 hours at 20ø to 25øC, 90 to 95% relative humidity. Concentrations of gas required during
exposure are 10 - 100 ppm (0.001 - 0.01%) for ethylene and 1000 ppm (0. 1%) for acetylene.
Concentrations of gases are controlled by ad lusting flow deliveries or the volume of ethylene
delivery liquids (such as ethephon). Air-tight rooms should have adequate air circulation to
enable uniform distribution of gas throughout the room. Build-up of carbon dioxide is to be
avoided as this reduces the effect of the ethylene and will have a detrimental effect on fruit
ripening. Under optimum conditions the air should be changed regularly (once every four hours)
and the ethylene reapplied.
Storage: - Prolonged storage of more than three to five days should not be used for
airfreighted fruits. Prolonged storage should only be used in the case of sea-freighted exports. At
storage temperatures below 12øC unripe mangoes will develop chilling in j dry, which will lead
to a drastic reduction in fruit quality and increase spoilage. Storage at 12øC, 85 - 95% relative
humidity will maintain the fruit in an acceptable condition, and which will ripen satisfactory on
transfer to higher temperatures. These criteria depend on the variety, harvest maturity and the
time of harvest in the season. Fully mature fruits have been found to show a reduced storage
capacity when compared to half-mature fruits, and this factor becomes more important as the
season progresses. Strict levels of quality control in low temperature stored fruit are essential, as
blemishes, bruises, damage and infections will manifest to a greater degree than when exported
by air and marketed rapidly. The potential exists in stored fruit for high levels of spoilage and
poor quality.
Shipment Conditions
For air-shipments, it is preferable, although not essential, that transport occurs on aircraft pallets
rather than in containers. Shipment in aircraft containers may result in build-up of heat and
ethylene which will accentuate ripening. For sea shipments, efficient reefer containers should be
used in preference to break bulk systems in the hold. Stacking systems should allow for
sufficient ventilation to assist in temperature maintenance.
Potential Post Harvest Losses
Mechanical Damage
Mechanically damaged fruit will normally deteriorate rapidly and should not be exported.
Damaged regions are susceptible to microbial infection, particularly when low temperature
long-term storage is used. Careful handling should therefore be used during harvesting and
handling
operations such as grading, packing and transportation.
Low Temperature
Storage at temperatures below 12øC will result in chilling injury, the symptoms of which include
inhibition of ripening, pitting, internal discolouration, prey scaldlike discoloration of the skin,
increased water loss, increased susceptibility to decay and detrimental changes in flavour.
Pathological Factors
Infection by micro-organisms is generally the most serious cause of postharvest losses in mango.
Disease incidence can be reduced by good orchard management, preharvest cultural practices,
appropriate handling and postharvest treatment procedures. Washing in static water tanks will
increase disease incidence due to the increase in inoculum from infected fruit, therefore, water
has to be changed frequently and contain sodium hypochlorite (100 ppm) and/or fungicide.
Post-harvest applications of specific fungicides will assist in disease control.
Anthracnose (Colletotrtchum gloeosporfofdes): infection occurs in the leaves, stem, young
flowers and fruits. In the first three, infection results in depressed black circular or angular
lesions; these enlarge and coalesce and affect large areas. Infections of the fruit are usually latent
and manifest only as the fruit begin to ripen. Anthracnose is characterized in ripening fruit by
small black circular lesions which gradually enlarge and coalesce as the fruit continues
ripening.
Stem end rot (Diplodfa natalensts) is particularly apparent during low temperature storage.
Infection is characterized by light grey-brown areas in the stem region. Infection is believed to
occur through the cut stem. Disease incidence can be reduced by leaving 1 cm of stem attached
to the fruit.
Rhizopus rot (Rhizopus oryzae) develops rapidly at 25øC and is characterized by skin
splitting and development of course white would with black spore heads. Infection takes place
after harvest, usually through mechanical injury. The incidence can be minimized by careful
handling, hygienic conditions and rapid cooling.
Jelly Seed is usually found only when the fruit is sliced; affected fruit show watery
translucent tissue around the stone towards the stem-end which then spreads. The condition is
found in harvested fruit but develops as the fruit ripens. The only means of control at present is
early harvesting, but which may result in the export of immature fruit.
Fruit Fly: restrictions are imposed on mangoes from some of the Caribbean islands into the
USA due to fruit fly. Fruit fly free status is given only to Grenada and St. Vincent; the other
islands cannot at present export mangoes to the USA without the introduction of specialized
equipment for quarantine procedures.
Mango Specifications
Markets
UK, Holland, U.S.A., Canada
Varieties
Julie, Graham, Grenada, Peach
Colour
Peel colour of mainly red, with yellow and green. Pulp colour yellow - orange.
Appearance
- Clean
- Free from blemishes, insect damage, fungal infection
- Uniform size and ripeness
Size
Julie mango
- Minimum weight: 250 g (8 ozs)
- Minimum length: 9.0 cm (3.5")
- Minimum width: 7.5 cm (3.0")
- Minimum breadth: 6.5 cm (2.5")
Graham mango
- Minimum weight: 350 g (12 ozs)
- Minimum length: 10.0 cm (4")
- Minimum width: 9.0 cm (3.5")
- Minimum breadth: 9.0 cm (3.5")
Grenada mango
- Minimum weight: 200 g (7 ozs)
- Minimum length: 8.0 cm (3")
- Minimum width: 7.0 cm (2.5")
- Minimum breadth: 7.0 cm (2.5")
Peach mango
- Minimum weight: 170 g (6 ohs)
- Minimum length: 7.0 cm (2.5")
- Minimum width: 6.0 cm (2.3")
- Minimum breadth: 6.0 cm (2.3")
Condition
- No latex stains;
- No harvest wounds, bruises or punctures
- No insect or disease damage
- Fruit at the required stage of harvest maturity
- Fruit at the required stage of ripeness
 Anthracnose
Disease
Market Requirements
All markets: Julie mangoes accepted as an Ethnic" mango and is sold as such. The other varieties
however, are purchased by ethnic and non-ethnic buyers and will generally sell in volume only
when fruit show a red blush, are already ripening and are free from blemishes.
Handling in Importer Markets
Unripe mangoes are susceptible to chilling injury below temperatures of 12øC and will not show
normal ripening. Storage in importing countries should be carried out at 12ø to 14øC. Unripe
fruit can be ripened by storage at 18ø to 25øC and treated with ethylene gas at 100 ppm (0.01%)
for 24 hours (the system used for bananas can also be used for mangoes). Ripe mangoes produce
ethylene and should be kept separate from ethylene-sensitive commodities.
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