Post Harvest 1

Development of plant

Initiation - Growth - Maturation - Ripening - Senescence - Death

Maturation

A stage in plant development that leads to physiological maturity

Physical Maturation

A stage in plant development of fully mature that continues to develop even it is harvest

Ripening

Process occurring after growth to early stage of senescence resulting in creation of specific characteristics

Senescence

Process after physical maturation leading to death of plant

Plant Growth Stages

Sprout - Seedling - Vegetative - Budding - Flowering - Ripening

Pre harvest

Crucial in agriculture and involve a range of practices and strategies to optimize crop production

Key preharvest activities

• Crop selection and planning

• Soil preparation

• Fertilization

• Pest and Disease control

• Weed control

Post harvest

Focuses on the handling, storage, processing and transportation of agriculture produce from the time of harvest until it reaches the consumer

Application of scientific and engineering

Importance of post harvest

• Preserve qualities

• Extension of shelf life

• Market access and value addition

• Reducing post harvest losses

• Food security

• Economic benefits

• Environmental impact

Post harvest lost

• Biggest problem affecting economic growth globally

• FAO estimated 1/3rd of loss in the food products occur every year

Factors of post harvest lost

Intrinsic factors

• Transpiration

• Respiration

• Ethylene production

• Change of chemical composition

• Ripening / senescence

Extrinsic factors

• Temp

• Humidity

• Gases

• Light and gravity

• Diseases and insect

Supply chain

Sorting - Packaging - Storage - Transport - Marketing - Consumers

Causes of post harvest losses in sorting phase

• Bruising

• Decay, insects and disorders

• Inefficiency

Causes of post harvest losses in packaging phase

• Contamination

• Leakage

• Bruising

• Environmental impact

Causes of post harvest losses in storage phase

• Heat, extreme cold

• Disorders

• Off flowers

• Overripening

Causes of post harvest losses in transport phase

• Overripening

• Bruising

• Breakage

Causes of post harvest losses in marketing phase

• Quality losses

• Improper retail conditions

• Consumers dissatisfaction

• Contamination

Transpiration / water loss

Evaporation of water from plants

Disadvantages of transpiration

• Weight loss

• Wilting or shriveling - loss appearance

• Decline in textural quality

• Loss of nutritive value

Stomata

In the underside of the leaf

Convert CO2 to O2

Responsible for transpiration

Lenticel

Pores in the produce responsible for transpiration

Cuticle

Cover the epidermis layers of fruits

Prevent water passing in/out of the crop

Bruises

Bruises caused from physical abuse

• Rubbing

• Dropping / Falling

Bruises cause a breakdown of tissues around bruised areas

Microorganisms can attack easier

Scars

Plant skin scarred leads to water loss and microorganism can enter

Benefits of transpiration

Some fruits benefit from water loss such mangosteen

• Its rough skin leads to several lenticels

• Rough skin have higher transpiration rate than smooth skin

• Water loss make the sugar and acid more concentrated making it more tasty

Respiration

Aerobic respiration (with O2)

Biochemical process in living cells to convert nutrients to energy

Fruit ripening process in climacteric fruits

High respiration rate

Ripen after harvest

Fruit ripening process in non-climacteric fruits

Stable low respiration rate

Will not ripen after harvest

Climacteric fruits

Ethylene production skyrockets during ripening process

Respiration process slowly goes down during development stage but goes up a bit during ripening

Non-climacteric fruits

Constant ethylene production

Respiration process go down overtime during development, ripening and senescence

Fruit growth

Changes from green to yellow banana

• Probiotics

• Resistant starch / sugar

• Phenolic compounds

• Acidity

• Taste

• Color

• Texture

• Odor / volatile compounds