Commercial Freezing

Question 1

How many different types of commercial freezing are there?

Answer 1

There are four different types

Question 2

Name the four different types of commercial freezing.

Answer 2

Blast freezing
Plate/contact freezing
Cryogenic freezing
Fluidised bed freezing

Question 3

At what temperature does blast freezing take place?

Answer 3

-30 degrees Celsius to -40 degrees Celsius

Question 4

How long does it take to freeze food using the blast freezing method of freezing?

Answer 4

2 and a half hours

Question 5

What foods can be blast frozen?

Answer 5

Fruit
Vegetables
Meat

Question 6

Describe how foods are blast frozen

2 points

Answer 6

Food is subjected to a blast of cold air (-30 to -40 degrees Celsius)
The cold air circulates around food as it travels through a specially designed tunnel on a conveyor belt

Question 7

At what temperature does plate/contact freezing take place?

Answer 7

-30 to -40 degrees Celsius

Question 8

How long does it take for foods to be plate/contact frozen?

Answer 8

1 hour to 90 minutes

Question 9

What foods can be plate/contact frozen?

Answer 9

Thin pieces of meat or fish

Meat or fish products e.g. fishfingers

Question 10

Describe how foods are plate/contact frozen plates

2 points

Answer 10

Food is placed on or between cool metal plates in an insulated cabinet
Food is frozen by direct contact with the metal surfaces which have been cooled by the circulation of a refrigerant e.g. ammonia at -30 to -40 degrees Celsius

Question 11

At what temperature does cryogenic freezing take place?

Answer 11

-196 degrees Celsius

Question 12

How long does it take to cryogenically freeze food?

Answer 12

A few minutes

Question 13

What foods can be cryogenically frozen?

Answer 13

Small fruits such as strawberries

Shellfish such as prawns

Question 14

Describe how foods are cryogenically frozen.

3 points

Answer 14

Cryogenic freezing is the most expensive method of commercial freezing
Cryogenic freezing produces the most superior products due to the very low temperatures of -196 degrees Celsius creating tiny ice crystals in food cells
Food is placed on a conveyor belt and moved into the insulated chamber where it is cooled by spraying with liquid nitrogen

Question 15

At what temperature does fluidised bed freezing take place?

Answer 15

-30 to -40 degrees Celsius

Question 16

How long does it take for fluidised bed freezing to freeze food?

Answer 16

10 to 15 minutes

Question 17

What foods can be frozen using the fluidised bed freezing method?

Answer 17

Small foods such as peas, sweetcorn and raspberries

Question 18

Describe how foods are frozen using the fluidised bed freezing method.
3 points

Answer 18

Food is subjected to a blast of cold air (-30 to -40 degrees Celsius) from underneath a perforated conveyor belt as it travels through a specially designed tunnel
This freezes the pieces of food separately so they don’t stick together
The constant movement of the food prevents the food from sticking together