Home Freezing

Question 1

What are the 3 underlying principles of freezing?

Answer 1

Uses freezing temperatures to inactivate microorganism growth and slow downs enzyme activity

Converts water into ice making it unavailable to microorganisms

Food is wrapped which prevents re-entry of microorganisms, prevents freezer burn and maintains colour, flavour, texture

Question 2

What are the two methods of home freezing?

Answer 2

Quick freezing and slow freezing

Question 3

Describe quick freezing.

4 main points

Answer 3

Food is quickly frozen at -25 degrees in the fast-freeze section of the freezer

Small ice crystals are formed inside the food which cause little damage to cell walls

Nutritional value, texture, colour and flavour are retained on thawing

Freezer should be turned to -25 degrees Celsius 6 hours prior to freezing

Question 4

Describe slow freezing.

3 main points

Answer 4

Food is frozen slowly at 0 to -18 degrees Celsius in the ice box area of a fridge or storage area of freezer
Large ice crystals are formed which damage cell walls of food
There is a loss of nutritional value, texture, colour and flavour on thawing

Question 5

List foods suitable for freezing

6 points

Answer 5

Fruit

Blanched vegetables

Meat, fish, poultry

Soups and sauces (leave airspace for expansion)

Bread, cakes, pastries

Convenience foods e.g. pizza

Question 6

List foods unsuitable for freezing

4 points

Answer 6

Mayonnaise (oil and water will separate)

Eggs in shell (egg white expands and shell shatters)

Foods with high water content e.g. cucumber (cell walls will become damage and food will become limp when thawed)

Soft cheeses e.g. cream cheese (become dry and crumbly?

Question 7

What are the five main advantages of freezing?

Answer 7

Nutritional value and sensory characteristics are retained if frozen correctly

Saves time, as individuals can bulk-purchase perishable foods

Saves money as foods can be bulk frozen and used on busy days instead of takeaways

Out-of-season foods are available all year round

Avoids food waste

Question 8

What are the four main disadvantages of freezing?

Answer 8

Initial cost of freezer can be expensive

Bulk-freezing can be time consuming especially is foods have to be prepared and cooked

Packaging is required which can be expensive

Defrosting can be time consuming and laborious