Fruits Processing Questions and Answers – Freezers

This set of Fruits Processing Multiple Choice Questions & Answers (MCQs) focuses on “Freezers”.

1. What is blast freezer?
a) Promotes rapid freezing
b) Promotes slow freezing
c) Promotes both rapid and slow freezing
d) Constant temperature maintenance
View Answer

Answer: a
Explanation: A blast freezer promotes rapid freezing. The faster the freezing leads to the smaller size of the crystals. Air blast freezing is the process of taking a product at a temperature and freezing it rapidly. Generally, the time taken to reach its desired storage temperature is 12 to 48 hours. It varies from product to product.

2. What is cryonics?
a) Low temperature freezing
b) High temperature freezing
c) Constant temperature freezing
d) Very high temperature freezing
View Answer

Answer: a
Explanation: Cryonics is the low-temperature freezing. Gases like nitrogen and carbon dioxide are often used for cryogenic freezing. The microbes are inactivated in the product. Thus, this process increases the shelf life of the product.

3. Why is quick freezing a preferred method?
a) Smaller ice crystals are formed
b) Very big ice crystals are formed
c) No ice crystals are formed
d) Big ice crystals are formed
View Answer

Answer: a
Explanation: In quick freezing, smaller ice crystals are formed. Hence there is less mechanical destruction of intact cells of the food. There is a shorter period of solidification and therefore less time for diffusion of soluble materials and separation of ice.

4. What liquid freezes things instantly?
a) Liquid nitrogen
b) Liquid ammonia
c) Dry carbon dioxide
d) Ethanol
View Answer

Answer: a
Explanation: Liquid nitrogen freezes things instantly. The rapid freezing is done by submerging the sample in liquid nitrogen or a mixture of dry ice and ethanol. Rapid freezing produces small crystals. It increases the quality of the food. The structure of the product does not affect much after thawing.

5. Does flash freezing kill bacteria?
a) True
b) False
View Answer

Answer: b
Explanation: Freezing foods renders bacteria inactive but doesn’t actually kill anything. Once the thawing process is done, the microbes are activated. Cooking it to the recommended temperature is the only way to ensure that the food is safe. Cooking it to the recommended temperature is the only way to ensure that the food is safe.

6. What is the meaning of IQF?
a) Individually quick frozen
b) Individually quick freeze
c) Intermediate quick frozen
d) Instant quick frozen
View Answer

Answer: a
Explanation: Freezing is a technology known as the individually quick-frozen (IQF) method. IQF is a method that does not allow large ice crystals to form in fruit cells. Also, since each piece is individually frozen, particles do not cohere. The final product is not frozen into a solid block.

7. Which of the following part is not present in the chest freezers?
a) Fan
b) Temperature controller
c) Defrost unit
d) Compressor
View Answer

Answer: a
Explanation: Chest freezers are the most economical freezer. Chest freezers do not have a fan, which limits the air circulation. It causes the temperature to be inconsistent, although as long as it can maintain a temperature below freezing, it will not affect the foods negatively.

8. Which of the following chiller is powered by steam?
a) Absorption
b) Evaporative
c) Centrifugal
d) Adsorption
View Answer

Answer: a
Explanation: The refrigerant in the absorption chillers is absorbed by the fluid sorbent. The commonly used refrigerant ammonia and water. The liquid sorbents used in this type of chillers are lithium bromide and water. The refrigerant is desorbed from solution at high temperatures.

9. Which of the following injury happens due to dehydration and oxidation?
a) Freezer burn
b) Chilling injury
c) Frost bite
d) Cold shrink
View Answer

Answer: a
Explanation: When a frozen food is damaged by dehydration and oxidation, then it called as freezer burn. The food is securely wrapped in air-tight packaging to prevent oxidation and dehydration. The food appears greyish brown with leathery spots on the product. It is generally due to inappropriate storage conditions.

10. What is chilling injury in fruits?
a) Caused by temperatures above the freezing point
b) Caused by temperatures below the freezing point
c) Caused by temperatures at the freezing point
d) Caused by temperatures variation
View Answer

Answer: a
Explanation: Chilling injury is the damage to plant parts caused by temperatures above the freezing point. Plants of tropical and subtropical origin are most susceptible. Chilling-injured leaves become purple or reddish and finally wilt. Both fruit and flowers of sensitive type can be injured.

11. At what temperature do chilling injury occurs?
a) 0 to 10°C
b) 10 to 15°C
c) -2 to -10°C
d) -5 to 10°C
View Answer

Answer: a
Explanation: Chilling injury is a form of cold damage. It occurs to certain species when exposed to non-freezing temperatures. Chilling injury can occur at temperatures from 0 to 10°C. It decreases the shelf life of the product. The appearance of the fruit is degraded.

12. What is frost damage?
a) Caused by temperatures above the freezing point
b) Occurs due to ice formation inside the plant tissue
c) Caused by temperatures at the freezing point
d) Occurs due to ice formation outside the plant tissue
View Answer

Answer: b
Explanation: Frost damage occurs when ice is formed inside the plant tissue and injures the plant cells. Frost damage may have a drastic effect upon the entire plant or affect only a small part of the plant tissue. This damage reduces yield of the produce. The quality of the product is also affected.

13. What is a chill unit??
a) Plant’s exposure to chilling temperatures
b) Chilling temperature of the freezer
c) Chilling temperature of the chiller
d) Ice formation of the plant
View Answer

Answer: a
Explanation: A chilling unit in agriculture is a metric of a plant’s exposure to chilling temperatures. Chilling temperatures depends on the freezing point and species. It helps to design storage conditions for the product.

14. What is advantage of contact freezer??
a) Designed to fit in limited space requirements
b) Easy to clean
c) Requirement of skill labor
d) Quick ice formation
View Answer

Answer: a
Explanation: Contact plate freezer can quickly freeze products by moving up and down the inside aluminum plates. The products exchange heat with two plates. Refrigeration system can be equipped as per different requirement and is flexible. It can be used on land or on vessel. It designed to fit in limited space requirements.

15. What is the other name for sharp freezing?
a) Slow freezing
b) Quick freezing
c) Instant freezing
d) Individual quick freezing
View Answer

Answer: a
Explanation: Slow freezing occurs when food is directly placed in the freezing rooms called sharp freezers. It is also known as sharp freezing. This method involves freezing by circulation of air by convection. The circulation of air is through a specially insulated tunnel, either naturally or with the help of fans.

Sanfoundry Global Education & Learning Series – Fruits Processing.

To practice all areas of Fruits Processing, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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