Lecture 2 - Part 2

Question 1

refers to the deterioration or decay of harvested crops due to microbial growth, physical damage, environmental conditions, or inadequate storage and handling practices.

Answer 1

Crop Spoilage

Question 2

A decline in the availability, utility and saleable weight.

Answer 2

Quantitative Loss

Question 3

A decline in acceptability by the consumer. A change in chemical constituents, appearance, nutritive value can decrease edibility and acceptability

Answer 3

Qualitative Loss

Question 4

Loss due to unintentional damage sustained by the commodity

Answer 4

Mechanical

Question 5

Loss due to disease organism and insects

Answer 5

Biological

Question 6

loss due to bacteria/fungi

Answer 6

Microbial

Question 7

Loss due to change in color, flavor, texture and nutritional value due to chemical constituents naturally present in crops

Answer 7

Chemical

Question 8

Loss due to faster rate of inherent processes in the produce or abnormalities

Answer 8

Physio-Chemical

Question 9

loss due to environmental factors

Answer 9

Physical

Question 10

loss due to human aversions

Answer 10

Psychological

Question 11

What are the causes of pH losses?

Answer 11

1. Physiological Deterioration
2. mEchanical Damage ( Physical Injury)
3. Disease andpests
4. Type of produce
5. Postharvest physiology
6. Respiration
7. Transpiration
8. Ripening
9. Extent of Postharvest Damage

Question 12

During postharvest handling, metabolic processes such as enzymatic reactions may occur, leading to changes in pH due to the breakdown of organic acids and other compounds.

Answer 12

Physiological Deterioration

Question 13

Physical injuries sustained during harvesting, handling, or transportation can disrupt cellular structures, accelerating enzymatic reactions and metabolic processes that contribute to pH changes.

Answer 13

Mechanical Damage

Question 14

Infections by pathogens and infestations by pests can lead to microbial growth and metabolic activities, resulting in the production of organic acids and other compounds that alter pH levels.

Answer 14

Disease and pests

Question 15

Different types of fruits and vegetables have varying pH levels, and factors such as cultivar, maturity stage, and environmental conditions can influence pH changes during postharvest handling.

Answer 15

Type of Produce

Question 16

The physiological processes occurring in produce after harvest, such as respiration, transpiration, and ripening, can affect pH levels through the production or consumption of organic acids and other metabolites.

Answer 16

Postharvest physiology

Question 17

The process of respiration in produce involves the breakdown of carbohydrates and release of carbon dioxide and organic acids, which can influence pH levels in tissues and surrounding environments.

Answer 17

Respiration

Question 18

Loss of water vapor through transpiration can concentrate organic acids and other solutes in produce, leading to changes in pH, particularly in dehydrated or desiccated tissues.

Answer 18

Transpiration

Question 19

fruits undergo biochemical changes, including the conversion of starches to sugars and the degradation of organic acids, which can affect pH levels and contribute to changes in flavor and texture.

Answer 19

Ripening

Question 20

The severity of postharvest damage, such as bruising, cuts, or lesions, can increase the exposure of tissues to enzymatic reactions and microbial activity, leading to pH alterations as a result of tissue breakdown and metabolic processes.

Answer 20

Extent of postharvest damage

Question 21

refers to the ongoing loss of water vapor from harvested crops, particularly perishable fruits and vegetables.

Answer 21

Transpiration

Question 22

Harvested produce remains fresh only as long as

Answer 22

it retains water

Question 23

rates can lead to dehydration, reduced quality and shorter shelf life of the produce

Answer 23

High transpiration

Question 24

is quite common during noon due to transpiration being higher than the rate of water absorption. Wilting reduces photosynthesis and other metabolic activities.

Answer 24

Wilting or loss of turgidity

Question 25

What are the negative effects of Transpiration?

Answer 25

1. Wilting 2. Reduced growth 3. Reduced Yield 4. Abscisic Acid 5. Wastage of Energy

Question 26

it prevents several plant processes and promotes abscission of leaves, flowers and fruits.

Answer 26

Abscisic acid

Question 27

What are the positive effects of Transpiration

Answer 27

1. It helps regulate leaf temperature, ensuring that the crops or plants remain cool and preventing heat stress during hot weather conditions. 2. It also aids in the transport of essential nutrients from the roots to other parts of the plant, supporting growth and development. 3. Transpiration helps prevent the growth of fungal pathogens, reducing the risk of diseases that can affect fruit and vegetable quality. 4. It also contributes to the production of volatile compounds that enhance the flavor and aroma of ripe fruits.

Question 28

What are the conditions causing high rates of transpiration

Answer 28

1. Low Relative Humidity (RH) 2. High Temperature 3. High wind velocity during transport

Question 29

Excessive transpiration leads to:

Answer 29

1. Loss in saleable weight 2. Wilting and shriveling 3. Toughening 4. Discoloration 5. Flavor changes 6. Loss in nutrients 7. Accelerated senescence

Question 30

Colorless and odorless gaseous compound, a plant hormone produced by all plant tissues more in some parts and when organs are wounded or stressed.

Answer 30

Ethylene

Question 31

it produces a high amount of ethylene

Answer 31

climacteric fruits

Question 32

Ethylene causes:

Answer 32

Ripening of fruits Abscission of leaves and petals of cutflowers Yellowing of leaves and fading of flower colors Epinasty of leaves and flowers Sprouting of root, tuber and bulb crops Toughening Development of bitter flavor such as in carrots and cabbage Induction of some physiological disorders (russet spotting in lettuce)

Question 33

What are the classification of produce according to ethylene production and commodity response

Answer 33

1. Stage of maturity 2. Physiological State 3. Environmental conditions 4. Stress and Mechanical Damage

Question 34

Immature commodities produce higher amounts of ethylene

Answer 34

Stage of maturity

Question 35

Ripening commodities produce more ethylene than unripe ones. More mature organs are more sensitive to ethylene,

Answer 35

Physiological state

Question 36

High temperature and the presence of external ethylene gas hasten production of ethylene in mature fruits.

Answer 36

Environmental conditions

Question 37

Any stress (water loss, insect or physical injury and rots) can increase ethylene production

Answer 37

Stress and Mechanical Damage

Question 38

refers to the metabolic process by which harvested crops continue to respire or undergo biochemical reactions, leading to the consumption of stored nutrients and the release of carbon dioxide, water vapor, and heat energy.

Answer 38

Post-harvest respiration

Question 39

the process of releasing water vapor containing oxygen in exchange for carbon dioxide.

Answer 39

Transpiration

Question 40

the exact opposite of photosynthesis and transpiration

Answer 40

Respiration

Question 41

process of using oxygen and producing carbon dioxide

Answer 41

Respiration

Question 42

it is used to breakdown and use food resulting in the release of carbon dioxide,

Answer 42

oxygen

Question 43

during respiration, fruits and vegetables consume oxygen and release carbon dioxide and water vapor. This process generates heat and can lead to the

Answer 43

loss of moisture content

Question 44

There is an inverse relationship between respiration rates and the postharvest life of fresh vegetables

Answer 44

The higher the respiration rate, the more perishable (shorter postharvest life) the commodity

Question 45

Respiration plays a major role in the postharvest life of fresh vegetables for the reasons:

Answer 45

1. Loss of substrate 2. Oxygen Requirements 3. Carbon dioxide Production 4. Release of Heat Energy

Question 46

Use of various substrates in respiration can result in loss of food reserves in the tissue and loss of taste quality (especially sweetness) and food value to the consumer.

Answer 46

Loss of Substrate

Question 47

An adequate O2 concentration must be available to maintain aerobic respiration. This should be considered in selecting the various postharvest handling procedures, such as waxing and other surface coatings, film wrapping, and packaging.

Answer 47

Oxygen Requirements

Question 48

Accumulation of CO2 produced by the commodity in its ambient atmosphere can 1 e beneficial or harmful, depending upon each commodity's tolerance to elevated CO2 Ievels

Answer 48

Carbon dioxide Production

Question 49

The heat produced by respiration (vital heat), which is about 673 kcal for each mole of sugar (180 g) utilized, can be a major factor in establishing the refrigeration requirements during transport and storage.

Answer 49

Release of Heat Energy

Question 50

fruits ripen after being harvested

Answer 50

Climacteric fruits

Question 51

fruits do not ripen after harvesting

Answer 51

Non-climacteric fruits

Question 52

have an increased respiration rate

Answer 52

Climacteric fruits

Question 53

do not display any increase in the rate of resporation

Answer 53

Non-climacteric fruits

Question 54

Signs or indicators of the readiness of the plant to harvest The basis for determining harvest date It involves assessment of some characteristics that changes as the crop matures It is compromise between indices that ensure the best eating quality and those that provide the needed flexibility in marketing It is the sign of minimum acceptability for majority of consumers

Answer 54

Maturity indices

Question 55

The characteristics of the commodity at different stages of maturity using a particular type of index

Answer 55

Maturity Standards

Question 56

What are the techniques of maturity determination

Answer 56

1. Use of Subjective Indices 2. Use of Objective Indices 3. Predicting when to harvest based on units

Question 57

Uses senses – can be visual of physical means Easy and inexpensive to apply Disadvantages: Not accurate enough to set standards Inconvenient for large scale enterprise It influenced by growing conditions

Answer 57

Use of Subjective Indices

Question 58

These are measurable indices Includes measurement of time, chemical constituents, rate of physiological characteristics More difficult to determine and sometimes time consuming but provides accurate measure of readiness of the commodity to be harvested.

Answer 58

Use of Objective Indices

Question 59

Best to predict when to harvest based on the growing temperature Recently developed techniques of determining maturity. New objective and non-destructive methods of determining maturity but requires expensive equipment and are usually used for research studies

Answer 59

Predicting when to harvest based on heat units

Question 60

drying of leaves, fullness of fingers, for export market, calibration size for the indication of fullness of fingers (by caliper measurements), number of days from the appearance of the falsehand

Answer 60

Banana

Question 61

Polygon on the rind become larger and spaces widen

Answer 61

Breadfruit (Rimas)

Question 62

Change from green to yellow or colour break stage or when predominantly yellowish green.

Answer 62

Carambola (Balimbing)

Question 63

In Philippines, Malaysia and Inddonesia, it is considered mature when it falls on the ground and ripe if it gives off distinctive odor; change in peel color (green to tinge of yellow); increase in spine stiffness; sap from stem becomes clear and not thick enough to stick on the fruit.

Answer 63

Durian

Question 64

Curd is compact and bright green; florets not yet open

Answer 64

Broccoli

Question 65

Tender when pierced with the thumb nail

Answer 65

Gourd

Question 66

Harvest when 50 – 75% of the plant leaves fall down and neck is small

Answer 66

Onion

Question 67

Harvest when 1/3 or ½ of the flowers opened

Answer 67

Baby Aster

Question 68

Flowers are fully open

Answer 68

Birds of Paradise ( Sterilizia)

Question 69

Harvest when the flower is half open

Answer 69

Calla Lily

Question 70

For immediate usage: ½ of the petals are open or when first two petals begin to unfold - For Storage: first two florets show color

Answer 70

Roses

Question 71

A good index should be

Answer 71

- quick and easy to determine - reliable - Independent of ripeness for fruits - Show a significant relationship with consumer acceptance

Question 72

WHY IS MEASURING LOSSES IMPORTANT?

Answer 72

- To implement strategies to minimize wastage and improve profitability. - identify areas where improvements in handling, storage, threshing, shelling, milling, drying, packaging, or transportation are needed to maintain product quality.