L3 - Postharvest Quality

Question 1

(Mechanical damage)

Disruption of cell membranes causes..?

Answer 1

• mixing enzymes and substrates
• release of elicitors
• browning
• release of aromas

Question 2

(Mechanical damage)

Disruption of cuticle causes…?

Answer 2

• increase in water loss
• increase in weight loss
• shriveling
• pathological infection

Question 3

What is the effect of bruising on respiration and ethylene production?

Answer 3

Both increase

Question 4

Senescence. Definition

Answer 4

It is the developmental stage towards death

Question 5

Senescence. Characteristics

Answer 5

• Endogenously controlled processes leading to death
• Genetically programmed
• Initiation of gene expression and enzymes activities
• Nucleus stays intact up to an advanced state of senescence
• Programmed Cell Death
• Ethylene

Question 6

Aging. Definition

Answer 6

Aging is not programmed.

Chronic degeneration, accumulation over time of sub-lethal damage
Exhausting of carbohydrates as respiratory substrate
Respiration rate: index of potential storage life

Question 7

Respiration rate : AGING

* the closer to the ground the lower the respiration rate

Answer 7

<5 : potato,onion grarlic
5-10 : carrot, celery,cabbage,head lettuce, cuccumber,tomato,pepper
12-20 : cauliflower, leaf lettuce, eggplant
20-30: brussels sprouts, spinach
>30 asparagus, broccoli
40-100 flowers (petals)

Question 8

Postharvest losses in industrialized countries

Food loss >40%

Answer 8

-focus on retail (improve post harvest management and communication within the chain)and
constumer (government and consumer awareness, quality aspects should match need and expectations)

Question 9

Post harvest losses in low income countries

Answer 9

-focus on post harvest (imporve infrastructure and educate) &
processing (improve product quality and search for new high value markets)

Question 10

Postharvest quality

Answer 10

1. Waste
2. Desirability (superior quality and shelf life)
3. Value (financial loss)