The
period between planting and harvesting is usually two
to two and half years. The stage of maturity at harvest
is dependent on the required storage or shelf-life and
the method of transportation to the export markets. Maturity
is judged by the level of yellow colouration of the "eyes"
of the fruit. Colour stages are categorised as follows:
• CS1: all eyes green,
no traces of yellow;
• CS2: 5 to 20% of the eyes yellow;
• CS3: 20 to 40% of the eyes yellow;
• CS4: 40 to 80% of the eyes yellow;
• CS5: 90% of eyes yellow, 5 to 20% reddish
brown;
• CS6: 20 to 100% of eyes reddish brown.
Sugar content should be assessed
in the field prior to harvesting to ensure adequate sugar
development. A minimum of 10% is generally required although
this may vary with the market. Sugar content is not always
related to the colour stage as agronomic and production
factors will affect sugar development.
For the export market where sea-shipment
for seven to fourteen days is used, fruits should be harvested
at CS1, where the fruits show no yellow colour development
on the eyes (ensuring that checks have been made on the
sugar content). For air-freighted shipments, although
generally cost prohibitive, harvesting can be carried
out at CS2 to 3. Those harvested at more advanced stages
are more susceptible to mechanical damage and over-ripeness.
Fruit
maturity can also be assessed on random samples by determination
of the flesh condition. This is carried out by slicing
the fruit horizontally at the point of largest diameter;
in fruit for sea-shipment export, the fruit should show
limited development of translucent areas. Where more than
half of the area is translucent, the fruit is considered
beyond optimum maturity.
Pineapples
harvested by hand are snapped from the stalk using a downward
motion. The fruit should be placed in field crates and
while in the field, left in shaded conditions. Collection
in the field and field to packhouse transport using sacks
or bags will cause mechanical damage and increase the
level of rejection. On arrival at the packing facility,
the stems and the crowns should be trimmed to 2 cm (0.5")
and 10 cm (4") respectively. Outgrading should be
made of all fruits which are undersize, oversize, over-ripe,
under-ripe (depending on the market requirements), damaged,
bruised or show fungal or insect damage.
Appearance
All fruits should be fresh and
clean with no shrivelling, discolouration or non-uniform
ripening. Colour should be yellow and green, with a green
crown.
Condition
• no
stains or surface debris
• no wounds from harvesting or handling, including
scratches, punctures or bruises
• no scars or residues from insect or spray
damage no soft rots or surface mould
• no fruit above or below the required colour
stage for shipment
Handling in Importing
Countries
Ripe
fruit should be stored at 7º
to 8ºC;
lower temperatures will result in chilling injury and
higher temperatures will lead to softening and decay.
For maximum storage life of unripe pineapples, the fruit
should be stored at 10ºC
and separate from ethylene producing products .
Export Grading and Packing
For reduction of post-harvest
disease incidence, the fruit should be treated, by dipping
or spraying, with a solution of Dowicide A (sodium 2-phenylphenolate)
at a concentration of 7 g per litre of water. Size grading
and packing should be carried out immediately after treatment.
ineapples
are packed according to the stage of ripeness and the
size of the fruit. Fruits in individual cartons should
be the same size, resulting in a range of counts. Accepted
counts are as follows:
The preferred method of packing
is to place the fruit vertically on the base, and then
to place dividers between the fruits to prevent rubbing
and movement. With some cartons, this is not possible
and fruit are laid horizontally in alternating directions;
where two layers of fruit are packed, a layer of card
is required between the layers.
• 6 count - 1.75 kg
fruit (3.8 lb)
• 12 count - 1.25 kg fruit (2.7 lb)
• 12 count - 1.00 kg fruit (2.2 lb)
• 20 count - 0.75 kg fruit (1.6 lb)
Fruits are normally
packed to a net weight of 10 to 15 kg (22 to 33 lb) depending
on the carton and the market. High value small pineapples
may be shipped in some instances at 6 kg (13 lb), whereas
the large fruit in some cases may be packed up to 20 kg
(45 lb).
Packaging
A full-telescopic two-piece fibreboard
carton with internal dividers between the fruit; bursting
strength 275 lb/in2. Top and bottom ventilation, in addition
to side vents are required, particularly where sea-shipments
in break bulk are used. Where staples are used in carton
construction, care should be taken to ensure complete
staples closure to prevent fruit damage.
Storage and Transportation
Where
sea-shipment is to be used, the fruit should be harvested
on the day prior to shipment. Green fruit should be stored
at 10ºC,
85 to 95% relative humidity, and under these conditions,
should have a storage life of two to three weeks. This
will be dependent on the sugar content and the agronomic
conditions during production, in addition to the handling
and storage procedures. Where exports are made by air
with fruit harvested at more advanced stages of maturity,
pre-export storage can be used and the suitable storage
temperature decreases to 7.5ºC,
85 to 95% relative humidity.
Potential Post-harvest Losses
Losses in pineapples during air-transport
are minimal if careful handling is employed. On sea-shipments
and long term storage however, the fruit are more susceptible
to post-harvest losses as a result of increased handling,
control of temperature and disease incidence.
Mechanical damage
Bruising or puncturing caused
by poor handling, dropping or abrasion, will result in
localised areas of softening and development of secondary
microbial infection.
Low Temperature
Sensitivity to chilling injury
is related to the level of ripeness of the fruit. Storage
of green fruit (CS 1) should be at 10ºC, 85 to 95%
relative humidity; storage for extended periods below
this temperature will result in chilling injury shown
by incomplete colour development, wilting and darkening
of the flesh and peel. Pineapples with 25% yellow eyes
can be stored for one week to two weeks at 5º
to 7ºC;
critical temperatures may be dependent on the production
area and growing conditions.
Pathological Factors
Black
rot caused by Ceratocystis results in a black watery rot
of the flesh and a thin brittle skin. Infection usually
occurs through the cut stem or through damaged areas,
but can generally be controlled by prompt treatment with
either Dowicide A or Thaibendazole.
Black spot or brown spot caused
by Penicillium funiculosum and Fusarium moniliformae results
in browning and sinking of the eyes and a browning of
the internal fruitlets. Incidence is not usually detected
until the fruit is cut. The diseases are believed to be
caused by mite damage in the field allowing entry of the
fungi. Pre-harvest spraying regimes are required to control
the mite population.
Endogenous Brown Spot
Physiological
disorder characterised by watery spots which eventually
coalesce and turn brown. The incidence is found in certain
varieties and production areas and is generally enhanced
during long term storage. |
