Fish Processing

Question 1

How can fish be processed?

3

Answer 1

Freezing

Canning

Smoking

Question 2

Explain the process of freezing fish.

Answer 2

Fish can be frozen by commercial blast freezing at -30 degrees degrees Celsius, or home freezing at -25 degrees Celsius

Question 3

Fish can be frozen commercially using which method?

Answer 3

Blast freezing

Question 4

At what temperature does blast freezing take place?

Answer 4

-30 degrees Celsius

Question 5

At what temperature does home freezing take place?

Answer 5

-25 degrees Celsius

Question 6

List the effects of freezing on fish.

5

Answer 6

No effect on colour, flavour and texture

Microorganisms are inactivated

Some loss of B-group vitamins and extractives during drip loss when thawed

Freezer burn may occur if packaging is damaged

Oxidative rancidity and enzyme deterioration can occur if fish is stored in the freezer for too long

Question 7

What are not affected by freezing.

3

Answer 7

Colour

Flavour

Texture

Question 8

What does freezing do to microorganisms?

Answer 8

Inactivates them

Question 9

What does freezing inactive?

Answer 9

Microorganisms

Question 10

How does freezing affect vitamins?

Answer 10

There is some loss of B-group vitamins during drip loss when thawed

Question 11

What is lost during drip loss when thawed?

2

Answer 11

B-group vitamins

Extractives

Question 12

When can extractives be lost from frozen fish?

Answer 12

During drip loss when thawed

Question 13

What may happen during freezing is packaging is damaged?

Answer 13

Freezer burn may occur

Question 14

What may occur if fish is stored in the freezer for too long?

Answer 14

Oxidative rancidity

Enzyme deterioration

Question 15

When can oxidative rancidity and enzyme deterioration occur in frozen foods?

Answer 15

When they have been stored for two long

Question 16

Give three examples of foods which are suitable of being frozen?

Answer 16

Cod

Salmon

Fish products, e.g. fish fingers

Question 17

Explain the process of canning

2

Answer 17

Fish is placed in sterile cans, sealed and heated to high temperatures.

Fish may be canned in oil, brine, spring water or a sauce, e.g. tomato sauce

Question 18

Give four substances that fish can be canned in?

Answer 18

Oil

Brine

Spring water

Sauce, e.g. tomato sauce

Question 19

Give an example of a sauce that fish can be canned in.

Answer 19

Tomato sauce

Question 20

List the effects of canning.

6

Answer 20

Colour, flavour and texture are changed

Loss of B-group vitamins, particularly thiamine B1

Microorganisms and enzymes are destroyed

Canned fish provides calcium, as the canning process softens fish bones so they can be consumed

Vitamins A and D are provided if fish is canned in oil

Calorie and fat content can increase if fish is canned in oil or a sauce

Question 21

What are changed during the canning of fish?

3

Answer 21

Colour

Flavour

Texture

Question 22

What happens to vitamins during the canning of fish?

Answer 22

There is a loss B-group vitamins, particularly thiamine B1

Question 23

What is the main vitamin lost through canning?

Answer 23

Thiamine B1

Question 24

What are destroyed by canning?

Answer 24

Microorganisms

Enzymes

Question 25

What happens to microorganisms and enzymes during the canning process?

Answer 25

They are destroyed

Question 26

What vitamin content is increased in the canning process?

Answer 26

Vitamins A and D

Question 27

When are vitamins A and D increased in canned fish?

Answer 27

If the fish is canned in oil

Question 28

What is increased if fish is canned in oil? | 2

Answer 28

Calorie and fat content increase if fish is canned in oil or a sauce Vitamin A and D content is increased

Question 29

Give three examples of fish that can be canned.

Answer 29

Tinned mackerel Tinned tuna Tinned salmon

Question 30

Explain the process of smoking fish. | 2

Answer 30

Fish is put in brine or rubbed in salt to give flavour and to act as a preservative It is then smoked by either cold or hot smoking

Question 31

During the smoking of fish what is done to the fish to flavour it or act as a preservative?

Answer 31

Put in brine or rubbed in salt

Question 32

After fish has been put in brine or rubbed in salt what is done to it?

Answer 32

It is either cold or hot smoked

Question 33

Explain the process of cold smoking fish. | 3

Answer 33

Involves subjecting fish to smoke from wood chips The chemicals creosote and formaldehyde in the smoke prevent microorganism growth on fish flesh The temperature does not go beyond 27 degrees Celsius, so the fish must be cooked before being consumed

Question 34

What chemicals are present in smoke that preserve fish?

Answer 34

Creosote Formaldehyde

Question 35

How does creosote and formaldehyde help preserve fish?

Answer 35

They prevent microorganism growth on fish flesh

Question 36

What temperatures are reached in cold smoking?

Answer 36

The temperature does not go beyond 27 degrees Celsius

Question 37

Does cold smoked fish need to be cooked before use?

Answer 37

Yes as temperatures only go to 27 degrees Celsius

Question 38

Explain the process of hot smoking fish. | 2

Answer 38

Follows the same process as cold smoking, but the temperature is gradually increased to approximately 80 degrees Celsius Fish does not require further cooking to be consumed

Question 39

What temperatures are reached in hot smoking?

Answer 39

80 degrees Celsius

Question 40

Does hot smoked fish need to be cooked before being consumed?

Answer 40

No as high enough temperatures are reached

Question 41

List the effects of smoking fish. | 4

Answer 41

Microorganisms and enzymes are destroyed Colour is changed, e.g. white fish will usually develop a light yellow or brown colour Flavour is changed to a distinctive, smoky taste Salt content is increased

Question 42

What are destroyed during smoking?

Answer 42

Microorganisms and enzymes

Question 43

What happens to microorganisms and enzymes during smoking?

Answer 43

They are destroyed

Question 44

What happens to the colour of fish during smoking? | 2

Answer 44

Colour is changed White fish will develop a light yellow or brown colour

Question 45

What happens to the white colour of white fish during smoking?

Answer 45

It becomes light yellow or brown

Question 46

What happens to the flavour of fish during smoking?

Answer 46

Flavour is changed to a distinctive, smoky taste

Question 47

What happens to the salt content of fish during smoking?

Answer 47

The salt content is increased