steps involved in post harvest handling of fruits

1. Introduction
Precooling
Sorting
Grading
Packaging

2. INTRODUCTION
• All fresh horticultural crops are high in water
content and are subjected to desiccation (wilting,
shrivelling) and to mechanical injury.
• Various authorities have estimated that 20-30 %
of fresh horticultural produce is lost after harvest
and these losses can assume considerable
economic and social importance.
• That is why, these perishable commodities need
very careful handling at every stage so that
deterioration of produce is restricted as much as
possible during the period between harvest and
consumption.

4. HARVEST
• Fruits harvested too early may lack flavour and
may not ripen properly, while produce harvested
too late may be fibrous or have very limited
market life.
• The level of maturity actually helps in selection of
storage methods, estimation of shelf life, selection
of processing operations for value addition etc.
The maturity has been divided into two categories
i.e. physiological maturity and horticultural
maturity.

5. • Physiological maturity: It is the stage when a
fruit is capable of further development or
ripening when it is harvested i.e. ready for eating
or processing.
• Horticultural maturity: It refers to the stage of
development when plant and plant part
possesses the pre-requisites for use by
consumers for a particular purpose i.e. ready for
harvest.

6. Maturity by size
Immature Half mature Mature

7. Maturity by color

8. WHY AFTER HARVEST IS IMPORTANT ?
• Domestic products are not exported regionally or
internationally because they do not meet the basic
standards of sizing, colour, shape, maturity, packaging,
labelling, etc.
• This is true for products for the fresh market as well as
products destined for processing.
• Unfortunately, the result is that domestic products have
lost market share locally to imports and, at the same time,
have not penetrated export markets.
• Further impeding expansion of this sector is the nearly
total lack of storage facilities to maintain product integrity
.

9. • Higher prices for fresh fruits and vegetables
require improved quality.
• High quality can only be achieved through proper
grading, sorting, packing, storage and handling of
fresh fruits and vegetables but requires a certain
level of new technology to accomplish it.

10. • It is important to minimize mechanical
damage by rough handling and bruising
during the different steps of pack house
operations. Secondly the pack house
operations should be carried out in shaded
area.
• Shade can be created using locally available
materials like, shade cloth, woven mats,
plastic tarps or a canvas sheet hung from
temporary poles.
• Shade alone can reduce air temperatures
surrounding the produce by 8-17°C.

11. HANDLING
Packing house operations
-Dumping / collection
- Pre-sorting
- Washing / Cleaning
- Sizing / Grading
- Bunching / Wrapping
- Postharvest Treatments
- Packing
- Cooling

12. DUMPING
• i) Dumping:
The first step of
handling is known as
dumping. It should be done
gently either using water or
dry dumping. Wet dumping
can be done by immersing
the produce in water. It
reduces mechanical injury,
bruising, abrasions on the
fruits, since water is more
gentle on produce. The dry
dumping is done by soft
brushes fitted on the sloped
ramp or moving conveyor
belts. It will help in removing
dust and dirt on the fruits.

13.  ii) Pre-sorting: It is
done to remove
injured, decayed, mis-
shapen fruits.
 It will save energy and
money because culls
will not be handled,
cooled, packed or
transported. Removing
decaying fruits are
especially important,
because these will
limit the spread of
infection to other
healthy fruits during
handling.

14. WASHING AND CLEANING
 iii) Washing and
Cleaning: Washing with
chlorine solution (100-
150 ppm) can also be
used to control inoculum
build up during pack
house operations. For
best results, the pH of
wash solution should be
between 6.5-7.5
 - Mangoes, bananas
should be washed to
remove latex.
 - Kiwifruit should be dry
cleaned or brushed after
curing or storage.

15.  iv) Sizing / Grading: Grading can be done
manually or by automatic grading lines.
Size grading can be done subjectively
(visually) with the use of standard size
gauges. Round produce units can be
easily graded by using sizing rings.

16. Grade designation and
quality of fruits
 :Minimum requirements are :
 Fruits should be
 a) clean, round, free from any visible
foreign matter
 b) fresh in appearance, free of pests
 c) free from damage caused by
pests or diseases
 d) free of any foreign smell and/or
taste

17. METHODS OF PRE-COOLING
• - Room cooling
• - Forced air cooling
• - Hydro cooling
• - Vacuum cooling
• - Package icing

18. ROOM COOLING
• It is low cost
and slow
method of
cooling. In this
method,
produce is
simply loaded
into a cool room
and cool air is
allowed to
circulate among
the cartons,
sacks, bins or

19. Advantages:
- Produce can be cooled and stored at the same room thus saves
on handling costs.
- No extra cost for pre-cooling equipment.
- Suits for crops, which are marketed soon after harvest.
Disadvantages:
- It is too slow method of cooling
- Space requirements for room cooling are more as compared to
storage.
- Unsuitable for packed produce.
- Excessive water is lost from the produce due to slow cooling.
Horticulture crops suitable for rooms cooling are: apple and
citrus

20. FORCED AIR COOLING
• ii) Forced-air cooling:
Forced air-cooling is
mostly used for wide
range of horticultural
produce.
• This is the fastest method
of pre-cooling. Forced air-
cooling pulls or pushes air
through the vents/holes in
storage containers.
• In this method uniform
cooling of the produce can
be achieved if the stacks
of pallet bins are properly
aligned.

21. HYDRO COOLING
• iii) Hydro cooling : The use of cold water is an old and effective
cooling method used for quickly cooling a wide range of fruits
and vegetables before packaging. For the packed commodities it is
less used because of difficulty in the movement of water through
the containers and because of high cost involved in water tolerant
containers. This method of cooling not only avoids water loss but
may even add water to the commodity. The hydro cooler normally
used are of two types :
• a) Shower type : In this type of hydro cooler, cold water is
pumped to an overhead perforated pan which produces a shower
over the produce which may be in bins or boxes or loose on a
conveyer belt passing beneath. The water leaving the produce may
be filtered to remove debris, then passed over refrigeration coil
where it is recoiled.

22. • b) Immersion type: In this
type of hydro cooler, the
produce is brought in contact
with cold water by using a
conveyor (flume type) or by
lowering bins / boxes in tank
of water which is
continuously cooled by
mechanical refrigeration
system.

23. • Advantages :
• Less energy is used as compared to forced air cooling.
• Hydro cooler can be easily integrated into an packing
operations and become a step within a simple packing line.
• Moisture loss does not take place.
• Disadvantages :
• Most of the packages don’t tolerate wetting.
• Wax layer of some fruits like pear, plum, apple are removed
by using spray type of hydro cooler :
• Horticultural produce suitable for hydro cooling are: Mango,
peach, cherry, asparagus etc.

24. • Immersion type hydro coolers usually take
longer time to cool produce than shower type
cooler. Generally the small quantity chlorine
or other chemicals are added in the water to
sanitize it.

25. HYDRO COOLING WATER TREATMENT
• The surface of wet commodities provides an excellent site
for diseases to thrive.
• Typically, hydro cooling water is treated with chlorine to
minimize the levels of decay-producing organisms.
Chlorine
in the form of hypochlorous acid from sodium
hypochlorite
• or gaseous chlorine is added to the hydro cooling water,
typically
• at the level of 50 to 100 ppm.

26. Vacuum cooling
• iv) Vacuum cooling: Vacuum
cooling take place by water
evaporation from the product at
very low air pressure.
• In this method, air is pumped
out from a larger steel chamber
in which the produce is loaded
for pre-cooling.
• Removal of air results in the
reduction of pressure of the
atmosphere around the
produce, which further lowers,
the boiling temperature of its
water.
• Vacuum cooling cause about 1
per cent produce weight loss
(mostly water) for each 6 0 C of
cooling.

27. • Advantages :
• Packed produce can be cooled if the pack
allows moisture transfer.
• Fast and uniform cooling takes place.
• Most energy efficient method.
• Disadvantages :
• High capital cost
• Produce losses more moisture

28. • To overcome the more loss of water from the
produce, another method of water spray vacuum is
used, (modification of vacuum cooling), called
hydro-vac cooling.

29. v) Package-icing :In some commodities, crushed
or flaked ice is packed along with produce for fast
cooling.
However, as the ice comes in contact with the
produce, it melts, and the cooling rate slows
considerably.
The ice keeps a high relative humidity around the
product. Package ice may be finely crushed ice,
flake ice or slurry of ice.
Packaged icing can be used only with water
tolerant, non-chilling sensitive products and with
water tolerant packages (waxed fibreboard, plastic
or wood).

30. Wax layer restricts
the gases interchange.
Air in the internal
Cavity

31. PACKAGING
• 􀂙 A coordinated system of preparing goods
for transport, distribution, storage, retailing
and end use.
• 􀂙 A means of ensuring safe delivery to the
ultimate consumer in sound conditions at
minimum cost.

32. Requirements of a Good Package
• 􀂙 Should be environment friendly.
• 􀂙 Should have sufficient strength in
compression and against impact and
vibrations
• 􀂙 Should be stable during the entire distribution
chain.
• 􀂙 Should be compatible with the automatic
packing/filling, handling machines
(mechanical filling systems)
• 􀂙 Should facilitate special treatments like pre-
cooling.
• 􀂙 Should have consumer appeal.
• 􀂙 Should be easily printable.
• 􀂙 Should be cost effective.

33. Materials for Packaging
• Wood – boxes, bins, trays, barrels, pallets
• Jute/canvas – sacks
• Paper and card board – liners, boxes, trays
• Plastic – Rigid - crates, pallets, trays
• Flexible – films (single & multi layered)
• Polystyrene boxes / trays
• Combined materials – CFB and plastic
• CFB has almost replaced wood and jute and is
considered as most important package material
to be used in combination with other materials.

36. Cushioning materials
• Dry grass, paddy straw, leaves, saw dust, paper
shreds etc. are used as cushioning material for
packaging fruits and vegetables
• It should dissipate the heat of respiration of the
produce
• It should be free from infection and should be
physiologically inactive
• Molded pulp tray, honeycomb portion, cell pack are
used replacing the cushioning material

37. Packaging Type:
• i) Bags and Sacks: Paper, polyethylene film, woven
polypropylene. These give little protection to the crop
from handling and transport damage, potato, onion,
cantos etc.
• ii) Woven Baskets: These are traditional containers
in which crops are placed after harvest. The produce
is damaged in these baskets when they are stacked
one above the other during transport and
distribution.
• iii) Wooden field box: These are made from thin
pieces of wood, widely spread so they are light in
weight and cheep to make. These can be used for
all types of fruits and vegetables.
• .

38. • iv) Plastic field boxes: They are strong and durable.
They are made from moulded polyvinyl chloride, poly
propylene or polyethylene. They have smooth surface,
which does not damage the produce. Initially, they are
expensive to buy, but can be used repeatedly.
• v) Pallet boxes: They are most commonly base on
the standard size for a European pallet of 1 x 1.2 m
and about 0.5 m high. These have capacity of about
500 kg. They are usually made from wood but plastic
ones are also available. They are used for whole
range of crops, which are commonly loaded into them
in the field and transported directly to the store.
• vi) Fibreboard boxes: They are made from either
laminated or more commonly corrugated fibreboard.
They may be used for directly field packing of produce
and transported to pack house or destination market

40. Lets sum up
Postharvest handling is the final stage in the
process of producing high quality fresh
produce.
Being able to maintain a level of freshness from
the field to the dinner table presents many
challenges. A grower who can meet these
challenges, will be able to expand his or her
marketing opportunities and be better able to
compete in the marketplace.

41. references
• Books;
)