Post harvest treatments encompass a range of practices applied to crops after harvesting to preserve quality and prolong shelf life. These methods include cleaning, sorting, cooling, packaging and storage among others.

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2. Post Harvest Treatments
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3. Contents
Physical Treatment Gaseous Treatments
Edible coating Ozone
Curing Ethylene
Heat Treatment 1-methylcyclopropene
Hot water Treatment Controlled Atmosphere storage
Irradiation Modified atmosphere packaging
Chemical Treatments
Antimicrobial and anti- browning agents
Nitric oxide
Sulphur di oxide
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4. Post Harvest Treatments
Treatments which applied to agricultural commodities
after harvest for the purpose of
Preservation
Conservation
Quality Control
Storage
Distribution
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5. Objectives of PHT
The three main objectives of applying postharvest technology to harvested fruits
and vegetables are:
to maintain quality (appearance, texture, flavor and nutritive value)
to protect food safety
to reduce losses between harvest and consumption.
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6. Physical Treatments
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7. Coating
Thin layer of material
which can be consumed,
provide barrier to oxygen
, external microbes ,
salute movement for food
In edible Coating a semi
permeable barrier
provided
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8. Aims
To increase a shelf life by decreasing
Moisture
Salute migration
Gas Exchange
Oxidative reaction rate
Respiration
Physiological disorder on fresh cut fruits
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9. Properties Good barrier properties
Improve appearance , mechanical
handling
Provide protective covering to
fruits, vegetables
Enhance shelf life
Enhance nutritonal components of
fruits and vegetables
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10. Examples
Fruits
Orange , apple grapefruits,
cherries, papaya, lemon, strawberry,
mango and peach
Vegetables
Tomatoes , cucumber and
carrot
This Photo by Unknown author is licensed under CC BY-SA.
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11. Classification
• Edible coatings mainly divided into three classes
Hydrocolloids Lipids Composites
Polysaccharide
Protein
alginate
Fatty acids
Acryl glycerides
waxes
Protein
Polysaccharide
lipids
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12. Benefits of Edible Coating
Reduction of weight and firmness loss
Maintence of quality during storage
Reduction of Metabolism and oxidation rate
Reduction of synthetic packaging
To retard on ethylene production
Best Consumer appeal
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13. Disadvantage
Thick coating prohibit oxygen exchange
Cause off- flavor development
Increase microbial growth
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14. Curing
''Curing is applied to the measures use to prepare starchy staple root crops and onions for
long term storage''
Have two types
Curing of roots and tubers
Curing dry bulb onion
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15. Curing of Fruits and Vegetables
Irish potato, sweet potato, winter squash, cassava,
garlic etc.
Cure garlic and onions
 At temperature 70-85 °C at 70% humidity
About two weeks, or until the necks are dry and tight.
Potatoes
Cured a bit cooler at 55 -65 °C and 95 % humidity
Two to three weeks
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16. Conti
Sweet potatoes
hot cure at 85 to 90 °C and 90 % humidity . For a week
Winter squash
Should be cured at 80-85 °C
For two to three weeks at 70 % humidity
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17. Objectives
Replace and
strengthen damage
areas of corky skin
1
Restore protection
against water loss
2
Reduce infection by
decay organism
3
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18. Conditions
• propriate temperature higher than ambient
• Atmosphere must kept moist
• Ventilation provided for new skin growth
• Temperature must be kept steady.
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19. Onion Bulb Curing
Carried out immediately after harvest
It's a drying-out process
Done by two ways
Natural curing
Take place after harvest under sun
Least expensive way
Enhance onion quality Artificial curing
Forcing heated air around onion
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20. Objectives
Access moisture
removal
Accumulation of
natural fungicidal
compounds in
skin
By exposing to
high temperature
Protection layer
formation
Serving as barrier
to infection
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21. Conti...
Not all vegetables
will respond well
to a curing
process
In fact, most
crops would be
ruined by leaving
them in warm
conditions
Some common
storage vegetables
that should not be
cured
include
beets, cabbage,
carrots, turnips
etc.
The temperature,
humidity and
duration of the
curing process is
different for the
various veggies
that require it
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22. Heat Treatment
 eat treatment is a pesticide-free method to care for texture quality during storage
 This method is conducted using hot air, hot water dips, or vapor heat, and is an
alternative to cut down the need to use chemical products to assure the quality of
fruits or vegetables
Why we Use heat treatment?
 heat treatments of fruit are used for
 insect disinfestation
 disease control
 to modify fruit responses to cold stress
 maintain fruit quality during storage
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23. Hot Water Treatment
Hot water treatment (HWT) is a non-conventional approach to control postharvest
decay based on the use of water at temperature above 40 °C
 The technique is completely safe for human and environment (residue-free and
environment-friendly) and of feasible use without registration rules
Hot water treatment can effectively improve the storage quality and shelf life of
harvested vegetables
The essence of this method is the heat transfer process in which heat is transferred
from the high-temperature treatment medium to the low-temperature fruit and
vegetable tissues
 Hot-water seed treatment is one method that you can use to eradicate, or at least
reduce the level of pathogens (particularly bacterial pathogens), in vegetable seed
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24. Example
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25. Irradiation
Food irradiation is a process that uses radiation to control
Pests
Microbes
insects in food and prevent spoilage
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26. Conti....
 Food irradiation is a process that uses
radiation to control
 Pests
 Microbes
Insects in food and prevent spoilage
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28. Gaseous Treatments
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29. Gaseous Treatment
 Ozone rapidly attacks bacterial cell crops
 more effective than chlorine against the thick-walled spores of plant pathogen and animal
parasite
Ozone can be employed in cold storage, washing system or process water sterilization.
fruits exposed to 2.5 ppm ozone had higher levels of total soluble solids, ascorbic acid content,
β-carotene content, lycopene content, and antioxidant activity .
Example
apples, cherries, carrots, garlic, kiwi, onions, peaches, plums, potatoes and table grapes
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30. ADVANTAGES OF OZONE
 Ozone oxidation is nature friendly process
 Significant reduction in processing time.
 Dissolves metallic substances like iron and
manganese.
 Removes unwanted color, taste, and odor of product.
DISADVANTAGES OF OZONE
 May produce undesirable aldehydes and ketones by
reacting with certain organics.
 Less soluble in water than chlorine
 it may degrades the material.
 The initial investment is more as compared to other
chemicals.
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31. 1-
Mthylcyclopropene
Maintains fruit cell wall integrity and peel color
develop aroma and flavor
 increase susceptibility to CO2 injury and chilling
disorders.
Additional exposure time is required for fruit to recover
its ability to ripen
Examples
apple, avocado, banana, broccoli, cucumber, date,
kiwifruit, mango, melon, nectarine, papaya, peach, pear
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32. Advantages
• 1 MCP advantages
• Quality maintenance of fruits during storage inhibiting browning preventing
decay deferring peel yellowing
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33. Ethylene
Triggers ripening process
Improve fruit color and quality
The concentration applied is within the range of 1 and 100ppm
Objectives
promote several benefits such as fruit thinning (apples, cherries)
fruit loosening prior to harvest (nuts)
color development (apples)
DE greening (citrus)
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34. Examples
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35. Advantages
 DE greening with ethylene applied to
 Accelerate the external color development • Make the fruit more attractive to consumer
Disadvantages
 Ethylene DE greening causes Loss of fruit quality
 Increased weight losses
 Shorter shelf life
 More chance of decay
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36. Controlled and Modified Atmosphere
Controlled atmosphere (CA) and modified atmosphere (MA) are techniques in which atmospheric gas
composition is different from normal and include the increasing of carbon dioxide (CO2) level, the
reduction of oxygen (O2) tension, or both
Controlled atmospheres (CA) slows ripening and maintains firmness, but also inhibits some flavor
development
 Sweetness and tartness are preserved to some extent by the use of CA, but other flavors may be
lessened in CA-stored fruit
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38. Chemical Treatments
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39. Chemical
Treatments
It includes treatment with Antimicrobial and anti-
browning agents, nitric acid And Sulphur dioxide
1
Antimicrobial and anti- browning agents
based solutions, peroxyacetic acid (PAA) organic
acids, hydrogen peroxide (1,0,) and electrolysed
water. NACIO has been one of the commonly used
disinfectants for fresh produce owing to its very
potent oxidizing properties
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40. 2
Nitric oxide
 Optimum NO levels delay the Chemical-based
agents include chlorine climacteric phase of many
tropical , fruits, prolong the postharvest storage life
by impeding ripening and senescence, suppress
biosynthesis of ethylene, reduce ethylene
production and, consequently, delay in fruit
ripening
3
Sulphur dioxide
 (50,) is widely used on table grapes to prevent
decay during
 storage
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41. Treatment with H,O, can extend the shelf life and reduce natural
and pathogenic microbial populations in melons, oranges, apples,
prunes, tomatoes, whole grapes and fresh-cut produce.
50, technology has also been tested for
control of postharvest decay on other fruits
such as litchi, fig. banana, lemon or apple
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42.  Optimum NO levels delay the climacteric phase of many tropical fruits,
 prolong the postharvest storage life by impeding ripening and senescence
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43. Advantages of Nitric Oxide
• Odorless and colorless
• Rapid-acting, full response usually within minutes
• Rapid offset, very safe
• Short exposure time suitable for busy catheterization lab setting
• No systemic adverse effects due to immediate inactivation by combining with
hemoglobin to form methemoglobin
Disadvantages of Nitric Oxide
• Requires cumbersome portable tanks for out-patient use at present
• Withdrawal syndrome consisting of deterioration of hemodynamics and gas
exchange poses a potential impediment to long-term use
• Administration technology very expensive at present
• Short duration of effect necessitates continuous administration if used long-term
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44. Advantages of Sulphur dioxide
• Sulphur dioxide is widely used in the food and drinks industries for its properties as a
preservative and antioxidant
• Whilst harmless to a healthy persons when used in recommended concentrations,
• It can induce asthma when inhaled or ingested by sensitive subjects, even in high
dilution
Disadvantages of Sulphur dioxide
• Sulfur dioxide affects the
• respiratory system,
• particularly lung function,
• and can irritate the eyes.
• Sulfur dioxide irritates the respiratory tract and increases the risk of tract infections.
• It causes coughing, mucus secretion and aggravates conditions such as asthma and
chronic bronchitis
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45. De-greening
'D-EGREENING' IS KNOWN AS THE
PROCESS OF ACQUIRING THE YELLOW
COLUR OF THE LEMON SKIN,
WHICH OCCURS NATURALLY DURING THE
FRUIT RIPENING PROCESS,
MAINLY DUE TO THE EXPOSURE OF FRUITS
TO LOW TEMPERATURES AT NIGHT AND
DURING THE MORNING DEW
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46. Conti....
 Ethylene gas is used
 Only mature fruits are de-greened
 Level of sugar and acids not affect Example :citrus fruit
 De-greening Practice Done to make
 The fruit color change
 Make the fruit for marketing season
 The practice of de-greening developed 100 years ago
 Success is dependent on
 -Initial peel color
 Temperature
 Duration of exposure
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47. De- greening of
Citrus Fruits
It is a process by which the green
color is removed from the peel by
treating the fruit with ethylene gas
to degrade chlorophyll and reveal
yellow and orange colors for
commercial and marketing
purposes.
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48. Application of ethylene for de-greening
Application of ethylene for de-greening;
Based on two biochemical processes,
Degradation of chlorophyll
Accumulation of carotenoids
which coordinately induce coloration of the peel
Cause of de-greening is activity of chlorophyllase enzyme
Explanation: Decomposition of green pigment in fruits is known as de-greening
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49. Factors Affecting De-greening
Harvest the fully mature fruit at the beginning of
natura
De-greening Immature fruit may be poorly
colored
Natural color break needs to have been
initiated at 7-13 °C night Temperature
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50. 1.Humidity
Low R.H may result in soft fruit and loss of size
Very low humidity may inhibit process
Best result with 90-95 percent
2.Temperature
Temperature varies with growing region
Optimum de-greening temperature for citrus is 25°C
High temperature inhibit carotenoids pigment (30 °C)
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51. Conti..
3.Air circulation
Good air circulation is required:
To equalize conditions of temperature, humidity, ethylene
in room To uniformly deliver ethylene
To remove unwanted products
4.Atmospheric composition
High carbon dioxide can inhibit ethylene Threshold values of carbon dioxide effect is not
clear
Oxygen concentration have influence
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52. Advantages
DE greening with ethylene
applied to
Accelerate the external color
development
Make the fruit more attractive
to consumer
Disadvantages
Ethylene DE greening causes
Loss of fruit quality
Increased weight losses
Shorter shelf life
More chance of decay
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53. Conclusion
This study was found that the post-
harvest treatments caused a significant
effect on
 color
 firmness
 weight loss
 moisture content
 dry matter content
 chilling injury
 total soluble solids
 PH
 vitamin C content
 disease incidence,
 disease severity and shelf life.
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54. References
• https://www.slideshare.net/mayasharma9026/controlled-atmosphere-and-modified-atmosphere-storage
• https://www.slideshare.net/monivijay/post-harvest-handling-of-fruits
• https://www.slideshare.net/SauravTuteja/management-of-postharvest-losses-in-fruits-and-vegetables
• Https://www.slideshare.net/BrahmeshReddy/post-harvest-treatment
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55. ANY
QUESTION
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56. THANK YOU
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