This document outlines various postharvest practices for fruits and vegetables. It discusses trimming, cleaning, and removing excess moisture from produce to facilitate handling and reduce disease. It also describes curing, waxing, standardization, grading, inspection, ripening, degreening, color adding, precooling, packaging, and techniques for fresh cuts. The objectives and methods are explained for each postharvest process along with the factors that affect them. References from textbooks on postharvest technology are provided.

1. Postharvest Practices
Kim John R. Nate
MS Plant Science
HORT 210
Republic of the Philippines
CENTRAL BICOL STATE UNIVERSITY OF AGRICULTURE
Calabanga | Pasacao | Pili | Sipocot

2. OUTLINE
A. Trimming, Cleaning, and Removal of Excess
Moisture
B. Curing
C. Waxing
D. Standardization, Grading, and Inspection
E. Ripening, Degreening, and Color Adding
F. Precooling and Refrigeration
G. Packaging
H. Fresh Cuts

3. A.) TRIMMING, CLEANING, and
REMOVAL OF EXCESS MOISTURE

4. Trimming
• General term for the removal of unwanted parts
• Removal of unwanted, discolored, rotten, and damaged parts

5. Specific Trimming Procedures
• Dehanding – separation of hand and removal of stalks in
banana
• Deflowering – removal of floral or stylar remnants
• Dethorning – removal of thorns
• Topping – trimming the tops and vegetative parts
• Dehusking – removal of husk
• Desilking – removal of silk
• Detopping – removal of crowns

6. Objectives of Trimming
• Facilitates handling
• Reduce likelihood of diseases
• Minimize damage
• Minimize transpiration
• Retards sprouting

7. Objectives of Trimming
Facilitates handling
- caters to the demand of the
consumers
Examples:
1. Thorns in Roses
2. Banana Peduncle
3. Husk and silk in baby corn
4. Crown of Pineapple
5. Wrapper leaves of Cabbage

8. Objectives of Trimming
Reduce the likelihood of
diseases
- removing damaged and rotten
parts which may contain inoculum
- Removal of floral remnants
which may harbor
microorganisms and pests
Examples:
1. Leafy parts of onion and garlic
2. Floral remnants of Banana
3. Rotten/damaged Leaves

9. Objectives of Trimming
Minimize damage
- Other parts may puncture other
fruits
Example: Removal of peduncle of
citrus
- Other parts are kept to protect
commodity
Example: Retained cabbage leaves

10. Objectives of Trimming
Minimize transpiration
- Greater surface area faster
and higher transpiration rate.
Examples:
1. Removal of carrot leaves
2. Removal of leaves in cut
flowers
3. Trimming of Taro petiole

11. Objectives of Trimming
Retards sprouting
- Removal of roots after
harvesting retards sprouting

12. Cleaning
• Removal of adhering dirt, latex, dust, insect, mold, and spray
residues to improve appearance.
Purpose:
1. To meet the demands of the consumers
2. To render the commodity more saleable
3. To reduce microbial load

13. Considerations in Appropriate Cleaning
Method
1. Nature of the
commodity
2. Need for maximum
elimination of dirt
3. Minimum water
consumption
4. Prevention of injury

14. Considerations in Appropriate Cleaning
Method
5. Rate of cleaning output
6. Consumer demand
7. Presence of latex

15. Considerations in Appropriate
Cleaning Method
8. Type of Commodity
9. Care in Harvesting
10. Season

16. Methods of
Cleaning
Washing
- Do not use colder water
- Addition of sanitizers,
fungicides, sulfates
Spray Washing
- Uses a jet of fresh
clean water
Soak and Rinse
- Placed in soaking
tanks to loosen
dirt
- Rinsed in second
tank

17. Methods of Cleaning
Chemicals used for wash water
Sanitizers
• Chlorine
• Hydrogen Peroxide
• Peroxyacetic Acid
• Ozone
Fungicides
• Thiabendazole
• Imazalil
• Azoxystrobin
• Fosetyl Aluminium
Sulfates
• Aluminium potassium
sulfate
• Magnesium Sulfate

18. Methods of Cleaning
Wiping
- Use of cloth to remove dirt
and sooty mold

19. Methods of Cleaning
Dry Brushing
- Use of brush to remove
adhering dirt and insects
without using water

20. Methods of Cleaning
Forced Air
- Use of pressurized air to
remove dirt and insects
Manual Removal
- Use of hands to remove dirt

21. Problems in Washing
Difficulty in removing
latex
• Water insoluble of the
latex
Solution:
• Separate tanks for
delatexing
• Use of alum
Prolonged washing
• Reabsorption of
water by the
commodity
Solution:
• Limit soaking time
• Reduce depth of
wash water
Spread of
Microorganism
• Microbial
accumulation in tanks
Solution:
• Wash in running
water
• Change regularly
• Trim befor washing

22. Water Elimination
• Removal of excess surface moisture after washing or waxing
• Done when commodities are wet
Purpose:
1. Prevents spread and growth of microorganisms
2. Prevention of fungicide dilution

23. Methods of Water Elimination
Drip Drying
- Placing of commodities in
slatted racks to drip-dried or
hang-dried
Use of High-Velocity Air
- For high volume of
commodities
- For small scale, electric fans
are used

24. Methods of Water Elimination
Use of foam rollers and dry
heat
- Produce is passed under a
series of foam rollers
- Enters dry heat tunnels
Dry Air in Tunnels
- Produce passed under a
canopy equipped with a fan
and heater

25. B.) CURING

26. Curing
• The process of toughening and self-healing in crops
a.) bruises and skinned areas of root and tuber crops
b.) reduction in moisture in citrus
c.) rapid closing of the neck of bulb crops

27. Methods of Curing
Bulb Crops
1. Solar Drying, windrowing,
or sun drying
2. Air or cold curing
3. Forced heated-air curing

28. Curing
Citrus
• Healing of wound via lignification
• Fruits are held in open racks
• Different curing temperatures and
period
Pummelo : Room Temperature for 1-2
weeks
Mandarin: 30°C for 3-5 days

29. Curing
Root and Tuber Crops
• Outdoor curing
• Stacked and covered
with materials like
canvass or woven
grass matts

30. Factors Affecting Curing
Temperature
• Optimum temperature is
higher than the normal
temperature of the crop
• Faster rate of wound
healing at higher
temperature
• Extreme temperature can
delay curing (<35°C and
>12°C)

31. Factors Affecting Curing
Relative Humidity
• High RH for root crops (80-95%)
• Low RH for bulb crops (60-70%)
Gases
• Carbon dioxide levels at 10% or
more, and oxygen below 5%
inhibits curing
• Periderm is not formed at
anaerobic conditions

32. Factors Affecting Curing
Type of Damage
• Smooth cuts heal faster than other wounds
• Ragged wounds causes longer curing
period
• Compression and impact damage can
inhibit periderm formation
Length of Period After Harvest
• Wound healing is quick on freshly
harvested commodities
• Wounds incurred after storage in root crops
heal slowly

33. C.) WAXING

34. Waxing
• Application of thin film of surface coating to fruits and
vegetables
Purpose:
• Intended to replace the natural coating of the commodity
which is removed during handling, or supplement it.

35. Appropriate Coatings
• Transparent
• Glossy
• Odourless
• Tasteless
• Biodegradable
• Safe
• Sufficient permeability to gas and
impermeable to semi-impermeable
to water

36. Materials for Wax Formulations
• Lipids
• Resins
• Polysaccharide-based
coatings
• Proteins
• Composite and Bilayer
coatings

37. Effects of Waxing
• Reduces moisture loss
• Maintains or enhances natural gloss
• Slows down respiration rate and
ripening process
• Carriers for inhibitors for senescence
and sprouting
• Carriers of fungicides and colorants
• Seals tiny scratches and injuries
• Reduces chilling injury in some crops

38. Methods of Waxing
• Dipping
• Foam Waxing
• Spray Waxing
• Slab or brush method
• Drip Method
• Controlled drop application

39. D.) STANDARDIZATION, GRADING and
INSPECTION

40. Grading
• The process of classifying the produce into groups according to a
set of criteria of quality and size recognized or accepted by the
industry
• Grades are the names of the groups under which produce are
classified
Example:
Extra Class, Class I, Class II

41. Grading
• Sorting – Process of classifying
produce into groups designated
by the person classifying them
according to whatever criteria
they desire.
• Sizing – classification of
produce according to sizes
Size Classifications:
Small, Medium, and Large

42. Benefits of Grading
• For consumers – assurance of quality
• For Farmers – sound basis for pricing
• For cooperatives – fairness in the sale of pooled produce
• For processors – eliminates sorting by processor
• For traders – establish business confidence

43. Benefits of Grading
• For buyers and sellers – provides common language in buying
and selling
• For truck-buyers – incur less damage
• For courts – facilitates settlements of disputes between
contracting parties
• For banks – establish loan value for produce
• For the general public – provides good price comparison

44. Standardization
• The process of formulation and issuing grade standards.
• Grade standards
• Product standard or standard itself
• Set of criteria and specifications of quality determining grades.
• Standards describe the characteristics of produce such as:
• Maturity
• Color
• Cleanliness
• Shape
• Freedom from decay and blemishes
• Uniformity

45. Characteristic of a Good Standard
• Acceptable
– Represents the consensus of opinions of participating
body
• Understandable
– clear, unambiguous and easy to understand
• Appropriate
– applicable to commercial varieties sold

46. Quality Criteria
• Appearance
– external condition
• Stage of Maturity and Ripeness
– commercial maturity
• Texture
– finger feel and mouth feel
• Damage or Defect
– any imperfection, deficiency, flaw
• Safety and Wholesomeness
– being clean and free from harmful contaminants

47. Inspection
• The process of measuring, examining, and testing samples to
determine whether the grade standard is have been
interpreted or appropriately enforced.
Types:
• Continuous Inspection – frequent inspection in the packing
line
• Inspection on a sampling basis – randomly selects
representative samples

50. E.) RIPENING, DEGREENING and COLOR
ADDING

51. Ripening
• Series of biochemical and physical processes that cause an
immature fruit to develop all the desirable characteristics of its
species
• Ethylene in the hormone that is responsible in the ripening
process

52. Ripening
Climacteric Fruits
• Fruits that can be picked
at green mature stage
which can be
subsequently ripened
Non-climacteric Fruits
• Fruits that need to be
picked at the ripe stage

53. Advantages of Ripening Regulation
• Allows shipment of green mature fruits
• Better color development
• Slower disease symptom expression
• Less fruit shrivelling
• Faster means of getting cash
• Takes advantage of transient prices
• Flexibility of selling
• Efficient use of space

54. Degreening
• Treatment with ethylene to
improve the color of non-
climacteric fruit
Examples:
Local oranges treated with
ethylene develop the orange
coloration

55. Ripening and Degreening
Techniques
Introduction of Ethylene or acetylene to
the environment of the fruit
• Ethylene
• Acetylene
• Bioethylene
Induce stress ethylene production
• Wounding fruit
• Plasmolysis

56. Ripening and Degreening
Requirements
Fruit Condition
• Fruits should be mature enough
Room Condition
• Uniformly low temperature
• Uniformly high humidity
• Good air circulation
• Air tight

58. Color Adding
• Application of dye to pale-colored commodities to improve
their color
• Done when degreened fruits do not produce desired color
intensity

59. Tinting
• Application of dye to white cut-flowers
• Done when flowers of a particular
color are not available
Methods
Contact Tinting – dipping into dye
solution for 4-8 seconds
Systemic Tinting – placing of the recut
stem of cut flowers into the dye solution

60. F.) PRECOOLING

61. Precooling
• Rapid cooling of the commodity to a
desired temperature soon after
harvest before it is stored or
transported.
Objective:
• To bring down the temperature of the
commodity to the optimum level as
rapidly as possible without inducing
physiological disorders or physical
damage

62. Benefits of Precooling
• Excellent quality of produce is maximized
• Minimizes refrigeration load
• Allows ripe fruit to be transported or stored

63. Methods of Precooling
• Room Cooling
• Forced Air Cooling
• Hydrocooling
• Vacuum Cooling
• Icing

64. G. PACKAGING

65. Packaging
• Art, science, and technology of bringing goods from their
source to the place of consumption at the minimum cost
possible
Functions of a package:
• Facilitate easy handling
• Protects produce
• Sells the produce
• Informs the consumer

66. Kinds of Packaging
• According to material
• burlap, fibrous materials, wood,
paper sheets, plastics
• According to protective capacity
• Flexible, semi-rigid
• According to design
• Bags and sacks, baskets, crates,
and boxes
• According to Storability
• Stackable, nestable, collapsible
• According to returnability
• One-trip containers, returnable

67. G. FRESH CUTS

68. Fresh Cut
• Preparation and handling cut
up fruits and vegetables
Types of Fresh Cuts
1. Ready to Cook
2. Ready to Eat
3. Ready to Process

69. Advantage of Fresh
Cuts
• Households
• Convenience
• Food Service Establishments
• Better portion control
• Processors
• Greater recovery of good quality
ready-to-process raw materials
• Exporters
• Minimized quarantine problem

70. References
• Bautista, O.K. and Esguerra, E.B. 2007. Trimming, cleaning, and removal of excess moisture.
Postharvest Technology for Southeast Asian Perishable Crops 2nd Edition. University of the
Philippines Los Baños.
• Esguerra, E.B. and Bautista, O.K. 2007. Waxing. Postharvest Technology for Southeast Asian
Perishable Crops 2nd Edition. University of the Philippines Los Baños.
• Agravante J.U. and Bautista O.K. 2007. Standardization, grading, and inspection. Postharvest
Technology for Southeast Asian Perishable Crops 2nd Edition. University of the Philippines
Los Baños.
• Agravante J.U. and Bautista O.K. 2007. Packaging. Postharvest Technology for Southeast Asian
Perishable Crops 2nd Edition. University of the Philippines Los Baños.
• Rimando, T.J., Bautista, O.K., Esguerra, E.B. 2007. Ripening, degreening and color adding.
Postharvest Technology for Southeast Asian Perishable Crops 2nd Edition. University of the
Philippines Los Baños.
• Flor, N.B., Esguerra, E.B., Masilungan, G.D. 2007. Preparation and handling of fresh cuts.
Postharvest Technology for Southeast Asian Perishable Crops 2nd Edition. University of the
Philippines Los Baños.

71. Thank you!