A lecture on the Importance of Postharvest Technology

1. Lecture 1
IMPORTANCE OF
POSTHARVEST TECHNOLOGY

2. LEARNING OBJECTIVES
At the end of the lesson, the learners are
expected to:
1. define post harvest technology;
2. determine its importance and objectives;
3. explain the causes of post harvest food losses
and the prevention measures;
4. carryout post harvest food loss assessment; and
5. determine the pre-harvest factors affecting the
post harvest life and quality aspects.

3. LESSON OUTLINE
1. Definition of Postharvest Technology (PHT)
2. Importance and Objectives of PHT
3. Causes of Post Harvest Food Losses and the
Prevention Measures;
4. Post Harvest food Loss Assessment; and
5. Pre-Harvest Factors Affecting the
Post Harvest Life and Quality Aspects.

4. Post-harvest technologies constitute an
inter-disciplinary science and techniques
applied to agricultural commodities after
harvest for the purpose of preservation,
conservation, quality control/enhancement,
processing, packaging, storage,
distribution, marketing, and utilization to
meet the food and nutritional requirements
of consumers in relation to their needs.
What is Post-Harvest Technology?
Sonam Tashi, nd

5. Post-harvest technology stimulates
agricultural production by:
 prevents post-harvest losses;
 improves nutrition ;
 adds value to agricultural products;
opens new marketing opportunities; and
 generates new jobs

6. Postharvest handling specifically involves
the movement and the operations that
commodities undergo from harvest to the time
immediately before meal preparation.

7. Its main concern is to keep commodities in
an acceptable state from harvest until it
reaches the consumer since most
commodities are transported in their
perishable state.

8. In addition, postharvest handling aims to
minimize losses at the least possible cost.
The existing postharvest environment
requires appropriate technologies to maintain
quality of commodities.
Poor handling of agricultural commodities
can result in quality deterioration and losses.

10. The three main objectives of applying
postharvest technology to harvested
fruits and vegetables are:
1)to maintain quality (appearance,
texture, flavor and nutritive value)
2) to protect food safety, and
3) to reduce losses between harvest
and consumption.

11. 􀀹 Vegetable and fruits products are usually of
high value (compared to grains) and need to
be handled carefully in order to preserve that
value.
􀀹 Vegetables and fruits are living
commodities and deteriorate in quality very
quickly.
Why is the study of postharvest
physiology and technology so
important?

12. 􀀹 A lot of money and other resources is
invested in growing the crop.
To get the best price possible for the
crop, it must be looked after appropriately
until it reaches the consumer.
􀀹 Vegetables and fruits are rich source of
vitamins, minerals, plant proteins and
medicinal substances - proper care helps
maintain nutritional and pharmacological
value.

13. Fresh fruits, vegetables, and flowers
must be in excellent condition and have
excellent quality if maximum shelf life is
desired.
The best possible quality of any
commodity exists at the moment of harvest.
From that point on, quality cannot be
improved, only maintained.
Remember that shelf life begins at harvest.
Remember:

14. Postharvest losses of commodities in the
Philippines represent a very significant loss of
10-50% of production output in developing
countries.
POSTHARVEST LOSSES IN THE PHILIPPINES

15. This means that one-tenth to one-half of all
the land, inputs, and labor used to produce the
commodities goes to waste.
When expressed in monetary terms, this
could amount to millions of pesos

16. In 2005, Philippine fruits and
vegetables were worth PhP 101.5 billion
(BAS, 2005).
An average loss of 35% thus amounts
to PhP 35.52 billion annually.
A loss reduction of 1% is equivalent to
PhP 355.2 million gain in productivity.

17. Globally, food losses and postharvest
waste are estimated at 30 to 40%
of production.
Losses of perishable foods such as
fruits and vegetables can be even higher
during the postharvest period, depending
upon the weather, access to storage or
distance from markets.

18. Utilizing improved postharvest
practices often results in reduced food
losses, improved overall quality and food
safety, and higher profits for growers and
marketers.

19. 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, and
 to reduce losses (both physical and in market
value) between harvest and consumption.
THE BASICS OF POSTHARVEST TECHNOLOGY

22. COMMODITY SHIPPING POINTS PERIOD
AMOUNT
LOST
(PHP)
SHIPPER/OWNER
'Saba' banana Davao to Korea 1987 32,000
Multinational
company
Banana, mixed load
Agusan del Norte to
Manila
2000 15,600 Consignee
Strawberry Baguio to Hongkong 1994 12,000 Cooperative
Papaya Negros to Manila Jan 1994 54,075
Agribusiness
Association
Seed Potato USA to Philippines 1993 1,000,000 Importer
Onion (stored) 1989 89,000,000 Bank
Source: Agravante et. al 2003
Table 1. Actual postharvest losses of selected perishable crops in the Philippines

23.  Rough handling
 Inadequate cooling and temperature maintenance
 Lack of sorting to eliminate defects before storage
 Inadequate packaging materials further add to the
problem.
COMMON CAUSES OF POSTHARVEST LOSSES
IN THE PHILIPPINES

24. In general, minimizing rough handling, sorting
to remove damaged and diseased produce and
effective temperature management will help
considerably toward maintaining a quality product
and reducing storage losses.

25. Storage life will be enhanced if the
temperature during the postharvest period is kept
as close to the optimum as feasible for a given
commodity.

26. The ideal temperature often depends on the
geographic origin of the product.
Tropical plants have evolved in warmer
climates and therefore cannot tolerate low
temperatures during storage.
Plants from tropical origins must be stored
above 12°C.
This is in contrast to plants which have
evolved in temperate, cooler climates which
can be stored at 0°C.
EFFECT OF TEMPERATURE ON POSTHARVEST

27. RECOMMENDED STORAGE TEMPERATURE
A SELECTION OF FRUITS AND VEGETABLES
1 - 4 °C 5 - 9 °C > 10 °C
Apple
Avocado (temperate
origin)
Avocado (sub-
tropical)
Asparagus Zucchini Pawpaw
Berry fruits French Bean
Grape fruit and
Lemon
Broccoli Passion fruit Mangoes
Peach and Plum Egg plant Banana
Cherry Capsicum Pineapple
Grapes Cucumber Sweet potato
Lettuce Mandarin orange Tomato
Mushroom Potato Pumpkin
Carnation Protea Ginger

28. The rapid cooling after harvest is so important.
If the temperature is lowered and the
harvested products are put in refrigerated
storage, water and quality loss can be reduced.
Fresh produce is alive, living and breathing.
The general term for all the processes going
on inside a living organism is called
metabolism.

29. Temperature has a big effect on the
rate of metabolism of the product.
When the temperature of the
product rises, so too does the rate of
metabolism.

30. Temperature has a big effect on the rate of
metabolism of the product.
When the temperature of the product rises, so
too does the rate of metabolism.

31. One of the main processes of metabolism is
respiration which is the process of
Temperature management for fresh produce is
the key to quality.
Lowering the temperature as quickly as
possible after harvest will slow the rate of
metabolism and therefore extend the product’s
shelf life.

32. High temperatures accelerate ripening and the
speed at which rots develop.
A 10o
C increase in temperature will cause fruit
and vegetables to deteriorate twice as fast, as
well as encouraging disease organisms to grow
twice as fast as well.

33. Causes of post-harvest losses of fresh fruits and
vegetables:
- use of uncertified seeds
- excessive use of fertilizer,
- poor irrigation system
- poor harvesting practices,
- supply exceeding demand
- limited access to loan
- handling: poor transport and storage
- diseases and pests
Assessment of post harvest losses

34. • Causes
of losses
at
different
points of
the
system
La Gra et al. 1990

35. Postharvest Loss Assessment for
leafy vegetable
• Producers are aware
that quality of produce
is affected by:
– Delay weeding
– Water management
– Fertilizer & pesticide use
– Disease and pests

36. According to policy makers, cultural practices affect quality
Seed quality 64% purity, germination
Seed
availability 36% supply not regular
Pests and
diseases 64% important concern
Safe
production 57%
pesticides uses,
fertilization
Kouame et Gnononfin, 2009

37. Traders
1- Transport and
Storage
Delay
Poor
infrastructures
(roads, storage)
2- Poor access to
markets
Middle Men
Supply>demand
3- Diseases and
Pests

38. Assessment of Post harvest losses
• Heating, yellowing,
weight loss
– Direct exposition to
sun
– Inadequate
ventilation during
packing, storage,
transportation
Types and major causes of Postharvest losses

39. • Physiological damages:
Softening
– Premature harvest
– Direct exposition to soil
– Direct exposition to rain
– Plastic packing material

40. • Physical damages
– Packaging (large
bags)
– Overloading
(transportation)
– Inappropriate
packing materials
– Poor road
conditions

41. Thank You!