This presentation is done by 2010/2011 batch of Export Agriculture students of Uva Wellassa University of Sri Lanka as a requirement for the subject which is “Post harvest technology”. Note that the information included here is relevant to Sri Lankan condition.
2. Introduction
• By the year 2050, the world population is expected to
reach 9 billion people
• Demand for food will increase by 60 percent
( United Nations Food and Agriculture Organization)
• Increasing food production is not enough
• Roughly one-third of the food produced in the world
goes to waste – a staggering 1.3 billion tons every year
• In the fight against global hunger, we must also address
postharvest los.
3. • Postharvest loss - Collective food loss all along the food
production chain, from harvest and handling, to
storage and processing, to packing and transportation
• The causes of postharvest loss are varied and complex,
depending upon weather, region, and crops
• But common culprits in the developing world include
lack of proper storage, lack of transportation, and lack
of information on where and how food is lost
• To escape from this problem, it is require to do
“Proper Post Harvest Handling”
4. Post Harvest Handling
• In agriculture, postharvest handling is the stage of crop
production immediately following harvest, including
cooling, cleaning, sorting and packing
• The instant a crop is removed from the ground, or
separated from its parent plant, it begins to deteriorate
• Post-harvest treatment largely determines final
quality, whether a crop is sold for fresh consumption,
or used as an ingredient in a processed food product
• Effective handling decreases postharvest losses
5. Citrus
Non climacteric fruit
Major Growing Areas : Dry and Intermediate
zones
Economics & Marketing availability
Lemon : April - August
Lime : April - July
Grapefruit : May -August
6. Scientific Classification
• Kingdom : plantae
• Phylum : magnoliophyta
• Class : magnoliopsida
• Order : sapindales
• Family : rutaceae
• Genus : citrus L.
7. Important Species
Citrus aurantiifolia – Key Lime
Citrus maxima – Pomelo
Citrus medica – Citron
Citrus reticulata – Mandarin orange
8.
9. Important hybrids
Citrus × aurantium – Bitter orange
Citrus × latifolia – Persian lime
Citrus × limon – Lemon
Citrus × limonia – Rangpur
Citrus × paradisi – Grapefruit
Citrus × sinensis – Sweet orange
Citrus × tangerina – Tangerine
Most of these varieties are resistant to post
harvest losses
12. Postharvest Deterioration
Harvested fruit continue respiration
Loose water but not replaced
The respiratory rate of the rind is nearly ten
times as high as that of vesicles
Rind plays a important physiological role in
the qualitative changes in storage
Respiratory rates are stimulated by dropping
and bruising
13. POST HARVEST HANDLING OF CITRUS
• Normally 30-40% of Citrus fruit loss due to lack of
proper post harvest handling practices
• Visible characteristics change in post harvest losses
– Anatomical Characteristics
– Physiological Characteristics
– Morphological Characteristics
14. TYPES OF POST HARVEST LOSSES
1. Physiological disorders
2. Diseases
15. 01. Physiological Disorders
• Influence quality in the markets
• Causes: Pre- and post-harvest factors
• Pre harvest: B, and Cu deficiency,
ammoniation, Zebra skin, fruit-splitting,
creasing, sun burn, wind scar and freezing
16. • Postharvest factors:
– Temperature, humidity, gaseous composition,
mechanical stress and aging
• Disorders: Puffiness, pitting, chilling injury,
granulation, oleocellosis,
stem end down, stylar-end breakdown,
and freezing injury
17. Blossom-End Clearing
BEC has also been referred as “wet bottoms,”
“stylar-end clearing,” “water bottom,”
“waterlog,” and “wet wick”
Symptoms:
– translucent, water soaked appearance of the
fruit peel (commonly at the blossom end)
– caused by internal bruising and juice leakage
from juice vesicles
18. BEC affected fruit develop off flavors
Visible within 24 hours after bruising
Can affect up to 90% of the fruit in some
loads
External symptoms of blossom-end clearing on
grapefruit (left) compared to an un-injured fruit (right)
20. Factors Involved in BEC Development
Fruit characteristics;
– Seedless grapefruit (e.g. 'Ruby Red' or 'Marsh')
are most affected
– Small fruit likely to develop BEC than large fruit
– Thicker-skinned fruit develop less BEC than thin-skinned
fruit under the same conditions
– The severity of BEC varies widely from year to
year and from grove to grove
– BEC develops most often in late-season fruit
21. • Rough Handling
– BEC never occurs while fruit are still attached to
the tree
– Never develop on fruit handled very gently
– Rough handling is the primary cause of fruit BEC
– Most BEC develops as a result of rough handling in
the packing house
22. • Temperature & RH
– BEC increases with higher temperatures
– Harvesting earlier in the morning ,when
fruit temperatures are cooler will reduce
the incidence of BEC
– Holding fruit at low humidities prior to
packing increases fruit susceptibility to BEC
compared to holding it at high humidities
23. Recommendations to Reduce BEC
• Carefully handle fruit during all harvesting and
packing operations
• Harvest fruit earlier in the morning when fruit
temperatures are lower
– Be cautious, however, that fruit are not so turgid that
oil spotting (oleocellosis) results
• Allow susceptible fruit harvested under warm
conditions to cool overnight (e.g. to 70oF or
below) before packing
• Always hold fruit under high relative humidities
24. Other Physiological Disorders
I. Granulation
• Fruit which is dry or ricey
• Causes:
– over maturity, sun burn, freezing, lack of
water, excessive tree vigor, mite damage,
cool, dry and windy conditions
• Keeping trees well irrigated will avoid fruit
from drying out
25. 2. Oleocellosis (Oil spotting)
• Navel oranges, lemons, and limes mostly
affected.
• Oil released from broken peel oil cells in the
flavedo.
• Oils are toxic to the surface of the peel and
cause necrosis of the surface cells
• Can reduced by avoiding harvest until the fruit
get turgid
26. Chilling Injury (CI)
• Collapse is not targeted oil glands
• A collapse of discrete areas of the peel from
sunken darkened lesions which will slowly
expand.
• Low RH enhance CI
• Waxing-Reduce but not eliminate CI
27. Stem-End Rind Breakdown
• Thin skinned fruit are more affected than thick
skinned fruit.
• Collapse of rind tissues resulting in sunken
brown area which is irregular in shape.
• Narrow ring of unaffected tissue immediately
around the stem area which has no stomata.
• Control
-Hold fruits at high RH
28. Post Harvest Diseases of Citrus Fruits
Anthracnose- Colletotrichium gloeosporioides
Septoria spot- Septoria depressa
Blue & Green Mould-
Penicillium digitatum (green mould)
P. italicum (blue mould)
Sour Rot- Galactomyctes citri-aurantii
29. Anthracnose
Symptoms
⁻ Superficial leathery appearance
⁻ Silver/grey to dark lesions
⁻ Tear-staining pattern
⁻ Pink spores under humid conditions
Occurrence
⁻ Infection occurs by rain-splash during autumn
⁻ Ethylene degreening increases sensitivity to
anthracnose
30. • Management
Dead wood should be pruned as the fungus
harbours in dead branches
Copper-based fungicides application before
monsoonal rains
Postharvest treatment with Benzimidazole
fungicides may reduce fruit losses
31. Septoria spot
• Symptoms
Dark brown collapsed lesions, with a purple tinges
Black specks develop in decayed area
• Occurrence
Mainly inland citrus regions
Fruit more susceptible after frosts
• Management
Field application of copper-based fungicides
32. Blue & Green Mould
Symptoms
Softening of damaged tissue
White fungal growth, which progressively
turns blue or green as spores develop
Occurrence
Infections develop from damaged areas
The growth of mould increases with
storage temperatures
Late season fruit more susceptible
33. Management
Good hygiene and sorting
Sanitation destroys spores in recirculating
water and packing line equipment
Apply postharvest fungicides within 24 hours
Lower storage
34. Sour Rot
• Symptoms
Very soft, watery decay
Distinct margin between decayed & healthy
tissue
• Occurrence
Infection occurs in damaged fruit
Sour rot spores in soil can accumulate in
recirculating water in dips and drenches
• Management
Careful handling reduces rind damage
Apply Guazatine fungicide within 24hrs of
harvest
36. Postharvest Storage
• Citrus fruits have relatively long post harvest
life
• Loose skinned fruits easily deteriorate at high
humidity
• Pre storage curing of the fruits also reduces
decay and chilling injury during storage
• Each variety has different optimum conditions
for storage
37. Controlled-atmosphere storage
Research has been done
Commercially not used because:
– Economic reasons
– Physiological characteristics of fruit
– Elevated CO2 has no beneficial effect
– Low O2 stimulates ethanol and
acetaldehyde
Thin skinned fruit are more affected than thick skinned fruit.
Collapse of rind tissues resulting in sunken brown area which is irregular in shape.
Narrow ring of unaffected tissue immediately around the stem area which has no stomata.