Question 1

If the fruits are coated with wax the rate of water loss can be reduced upto ;
A)20-30%
B)30-40%
C)40-50%
D)30-50%

Accepted Answer

Coating fruits with wax can significantly reduce the rate of water loss, and the reduction can range from 30% to 50%. This is because the wax coating acts as a barrier to water vapor, slowing down the process of transpiration and thus reducing water loss.

Question 2

Sweet potatoes can be cured at around 30°C and 90-95% RH for;
A)1-2 days prior to storage
B)2-5 days prior to storage
C)4-7 days prior to storage
D)7-8 days prior to storage

Accepted Answer

Sweet potatoes are typically cured at around 30°C and 90-95% relative humidity for 4-7 days prior to storage. This process helps heal any wounds, reduces the chances of rot, and improves sweetness by converting starches to sugars.

Question 3

In apples internal breakdown can be reduced during cold storage by treating with;
A)Sodium
B)Magnesium
C)Calcium
D)Potassium

Accepted Answer

Calcium treatments are known to reduce internal breakdown in apples during cold storage by enhancing the fruit's structural integrity and delaying senescence.

Question 4

The most common packing material used for mango and citrus in Pakistan is;
A)Plastic bins
B)Bamboo baskets
C)Polythene bags
D)Wooden crates

Accepted Answer

The answer of The most common packing material used for...

Question 5

The optimum storage temperature for apple ranges from;
A)0-1°C
B)2-5°C
C)5-10°C
D)10-15°C

Accepted Answer

The optimum storage temperature for apples is 0-1°C to slow down the ripening process, reduce moisture loss, and prevent spoilage, ensuring the apples remain fresh for a longer period.

Question 6

After harvest the rate of respiration increases in;
A)Tropical fruits
B)Non-climacteric fruits
C)Temperate fruits
D)Climacteric fruits

Accepted Answer

Climacteric fruits experience an increase in respiration rate after harvest, which is associated with the ripening process.

Question 7

Which is the best indicator of metabolic activities and potential storage life of fresh produce;
A)Rate of transpiration
B)Rate of respiration
C)Rate of ethylene production
D)Rate of weight loss

Accepted Answer

The rate of respiration is the best indicator of metabolic activities and potential storage life of fresh produce because it reflects the intensity of metabolic processes occurring within the produce, directly impacting its shelf life and quality.

Question 8

As storage period of most fruits is increased, acidity and vitamin C;
A)Increase
B)Decrease
C)Remain same
D)Acidity increases while vitamin c decreases

Accepted Answer

The answer of As storage period of most fruits is...

Question 9

During curing of tuber crops;
A)Excessive moisture is lost
B)A waxy layer is developed on the fruit
C)Storage life increases
D)All of above

Accepted Answer

During curing of tuber crops, excessive moisture is lost, a waxy layer is developed on the fruit, and storage life increases.

Question 10

The most common radiation dose used for extending shelf-life of fruits and vegetables ranges between;
A)0.01-3.0 kGy
B)5-10 kGy
C)10-20 kGy
D)20-30 kGy

Accepted Answer

The most common radiation dose for extending the shelf-life of fruits and vegetables is between 0.01-3.0 kGy. This range is effective for delaying ripening and sprouting, inhibiting pests, and reducing spoilage without compromising the quality of the produce.

Question 11

In controlled atmosphere storage;
A)Temperature and RH is controlled
B)Nitrogen concentration is controlled
C)Oxygen and carbon dioxide is controlled
D)All of the above

Accepted Answer

The answer of In controlled atmosphere storage;
A)Temperature and RH is...

Question 12

Chilling injury is common in;
A)Temperate fruits
B)Tropical and sub-tropical fruits
C)Deciduous fruits
D)None of above

Accepted Answer

Tropical and sub-tropical fruits are more susceptible to chilling injury because they are not adapted to cold temperatures. When exposed to temperatures below their optimal range but above freezing, physiological damage occurs, affecting their quality and shelf life.

Question 13

Which enzyme is involved in ethylene synthesis;
A)ACC synthase
B)ACC oxidase
C)Endoploygalacturonase
D)a & b

Accepted Answer

ACC synthase and ACC oxidase are both involved in the synthesis of ethylene in plants. ACC synthase converts S-adenosyl methionine to 1-aminocyclopropane-1-carboxylic acid (ACC), which is then converted to ethylene by ACC oxidase.

Question 14

Safe storage temperature for most mango cultivars is;
A)5-6°C
B)7-8°C
C)13°C
D)1-2°C

Accepted Answer

Most mango cultivars are best stored at temperatures around 13°C to prevent cold injury and to maintain quality during storage.

Question 15

During storage of most fresh produce the relative humidity should be;
A)50-60%
B)65-75%
C)70-80%
D)85-95%

Accepted Answer

Most fresh produce requires a high relative humidity level of 85-95% during storage to reduce water loss and wilting, maintaining freshness and extending shelf life.

Question 16

Which crop has higher respiration rate;
A)Cabbage
B)Grapefruit
C)Potato
D)Tomato

Accepted Answer

The answer of Which crop has higher respiration rate;
A)Cabbage
B)Grapefruit
C)Potato
D)Tomato...

Question 17

Silver thiosulphate extend vase life of cut flowers by;
A)Anti-bacterial properties
B)Anti-oxidant properties
C)Anti-ethylene properties
D)Anti-auxins properties

Accepted Answer

The answer of Silver thiosulphate extend vase life of cut...

Question 18

Which one is the non-climacteric fruit;
A)Apple
B)Mango
C)Peach
D)Citrus

Accepted Answer

Non-climacteric fruits, unlike climacteric fruits, do not continue to ripen once they are picked from the plant. Citrus fruits are an example of non-climacteric fruits, meaning they do not ripen or improve in quality after harvest.

Question 19

Internal browning in fresh produce is the result of ;
A)Depletion of carbohydrates
B)Action of polyphenoloxidase (PPO)
C)Loss of moisture
D)Loss of chlorophyll

Accepted Answer

Internal browning in fresh produce is primarily caused by the action of polyphenoloxidase (PPO), an enzyme that catalyzes the oxidation of phenolic compounds to quinones, which then polymerize to form brown pigments.

Question 20

In onions the maturity is determined by;
A)Bulb size
B)Bulb colour
C)Leaves colour
D)Tops drooping

Accepted Answer

The maturity of onions is typically determined by the tops drooping, which indicates that the plant has stopped growing and the bulbs are ready for harvest.

Quiz 31: Postharvest Practices and Storage Techniques for Fresh Produce

If the fruits are coated with wax the rate of water loss can be reduced upto ;

Sweet potatoes can be cured at around 30°C and 90-95% RH for;

In apples internal breakdown can be reduced during cold storage by treating with;

The most common packing material used for mango and citrus in Pakistan is;

The optimum storage temperature for apple ranges from;

After harvest the rate of respiration increases in;

Which is the best indicator of metabolic activities and potential storage life of fresh produce;

As storage period of most fruits is increased, acidity and vitamin C;

During curing of tuber crops;

The most common radiation dose used for extending shelf-life of fruits and vegetables ranges between;

In controlled atmosphere storage;

Chilling injury is common in;

Which enzyme is involved in ethylene synthesis;

Safe storage temperature for most mango cultivars is;

During storage of most fresh produce the relative humidity should be;

Which crop has higher respiration rate;

Silver thiosulphate extend vase life of cut flowers by;

Which one is the non-climacteric fruit;

Internal browning in fresh produce is the result of ;

In onions the maturity is determined by;