1. INJURIESINJURIES

2. All horticultural products are sensitive to variousAll horticultural products are sensitive to various
injuries after harvest. The extent of type injury willinjuries after harvest. The extent of type injury will
vary with each product, the variety, the maturity, thevary with each product, the variety, the maturity, the
water content, the handling system, the form ofwater content, the handling system, the form of
packaging used and the condition of the product.packaging used and the condition of the product.
There are four main forms of injury on fresh produce.There are four main forms of injury on fresh produce.
They are :They are :
 Mechanical injuryMechanical injury
 Pathological injuryPathological injury
 Insect and rodent injuryInsect and rodent injury
 Physiological injuryPhysiological injury

3. Mechanical InjuryMechanical Injury
 Mechanical injury reduces the quality andMechanical injury reduces the quality and
saleability of a product through loss of visualsaleability of a product through loss of visual
appearance, increases the rate of deteriorationappearance, increases the rate of deterioration
through water loss and increases itsthrough water loss and increases its
susceptibility to decay.susceptibility to decay.
 There are three types of mechanical injuryThere are three types of mechanical injury
 ImpactImpact
 CompressionCompression
 VibrationVibration

4.  Impact mechanical injury is caused by dropping aImpact mechanical injury is caused by dropping a
product onto another product or a hard surface.product onto another product or a hard surface.
Impact injury is often caused by high drop heights inImpact injury is often caused by high drop heights in
harvesting and packing line equipment, manualharvesting and packing line equipment, manual
handling and poor forklift operation.handling and poor forklift operation.
 Compression mechanical injury is caused by trying toCompression mechanical injury is caused by trying to
put too much product into a package of specifiedput too much product into a package of specified
volume.volume.
 Vibration mechanical injury is also referred to asVibration mechanical injury is also referred to as
transit as this when it is most likely to occur.transit as this when it is most likely to occur.

5. Pathological InjuryPathological Injury
 The method of handling fresh produce afterThe method of handling fresh produce after
harvest will largely determine the extent ofharvest will largely determine the extent of
decay development postharvest.decay development postharvest.
 Postharvest decay of fresh produce is causedPostharvest decay of fresh produce is caused
by fungi, bacteria and in a few cases, viruses.by fungi, bacteria and in a few cases, viruses.
 Maturity of the product will also influence aMaturity of the product will also influence a
product’s susceptibility to decay.product’s susceptibility to decay.

6. Insect and rodent injuryInsect and rodent injury
 Insect and rodent injury reduces theInsect and rodent injury reduces the
appearance of horticultural products.appearance of horticultural products.
 Aside of from visual damage, the injury willAside of from visual damage, the injury will
also increase the rate of production ofalso increase the rate of production of
endogenous ethylene and provide an entryendogenous ethylene and provide an entry
point for decay, both of which will hastenpoint for decay, both of which will hasten
deterioration and shorten shelf-life.deterioration and shorten shelf-life.

7. Physiological injuryPhysiological injury
 The most common causes of physiological injury areThe most common causes of physiological injury are
incorrect temperature management or a mineralincorrect temperature management or a mineral
nutrient deficiency during growth and development.nutrient deficiency during growth and development.
 The susceptibility of products to physiological injuryThe susceptibility of products to physiological injury
depends on :depends on :
 The varietyThe variety
 The product maturity at harvestThe product maturity at harvest
 The crop production practicesThe crop production practices
 The weather conditions present during growthThe weather conditions present during growth
 The size of the productThe size of the product
 The harvesting practicesThe harvesting practices

8. Temperature injuryTemperature injury
 Correct temperature management is the singleCorrect temperature management is the single
most important tool in controlling the rate ofmost important tool in controlling the rate of
deterioration of fresh produce.deterioration of fresh produce.
 There are three forms of temperature injury :There are three forms of temperature injury :
 High temperature injuryHigh temperature injury
 Chilling injuryChilling injury
 Freezing injuryFreezing injury

9. High temperature injuryHigh temperature injury
 At temperatures above 30At temperatures above 30oo
C, biochemical activity inC, biochemical activity in
the product may be adversely affectedthe product may be adversely affected
 If temperatures go above 40If temperatures go above 40oo
C, the enzymes start toC, the enzymes start to
become inactivated.become inactivated.
 Product death will occur in some tissue atProduct death will occur in some tissue at
approximately 45approximately 45oo
C.C.
 Under high temperature conditions, color fails toUnder high temperature conditions, color fails to
develop properly and often there is a loss of color.develop properly and often there is a loss of color.

10. Chilling injuryChilling injury
 Chilling injury is a physiological disorder thatChilling injury is a physiological disorder that
induced by exposing certain products to low, but non-induced by exposing certain products to low, but non-
freezing temperature for a certain period.freezing temperature for a certain period.
 The extent of any chilling injury will be determinedThe extent of any chilling injury will be determined
by three factors :by three factors :
 The temperatureThe temperature
 The duration of the exposureThe duration of the exposure
 The sensitivity of the product to chilling injuryThe sensitivity of the product to chilling injury

11.  The actual temperature that will cause chilling injury is veryThe actual temperature that will cause chilling injury is very
product specific. For example, pineapples have been shown toproduct specific. For example, pineapples have been shown to
chill at temperatures below 25chill at temperatures below 25oo
C.C.
 The lower the temperature below the critical chillingThe lower the temperature below the critical chilling
temperature, the less time it takes for the injury to occur andtemperature, the less time it takes for the injury to occur and
the more severe it will be.the more severe it will be.
 The typical symptoms of chilling injury include :The typical symptoms of chilling injury include :
 An increased incidence decayAn increased incidence decay
 Discoloration externally and internallyDiscoloration externally and internally
 Irregular ripening or failure to ripen altogetherIrregular ripening or failure to ripen altogether
 Textural changesTextural changes
 Off-flavors and off-odorsOff-flavors and off-odors
 Reduced nutritive valueReduced nutritive value

12. Freezing injuryFreezing injury
 Plant tissue will freeze below 0Plant tissue will freeze below 0oo
C.C.
 Most products freeze between 0Most products freeze between 0oo
C and -2C and -2oo
C.C.
 Freezing of water may take place eitherFreezing of water may take place either
intracellurarly (within the cell) which is usually fatalintracellurarly (within the cell) which is usually fatal
or extracellularly (outside of the cell).or extracellularly (outside of the cell).
 When a cell’s contents freeze they expand in size,When a cell’s contents freeze they expand in size,
rupturing the cell wall. Upon thawing, the productrupturing the cell wall. Upon thawing, the product
disintegrates into a “water sack”.disintegrates into a “water sack”.