Preservation by quick-freezing of raw foods and cooked foods

During the cooking and freezing process, foods undergo physical and/or chemical changes. If it is found that these changes are detrimental to the product, then recipe modification is required. The following products require some modification: sauces, casseroles, stews, cold desserts, batters, vegetables and egg dishes.

Rapid freezing of foodstuffs can be achieved by a variety of methods using different types of equipment, for example:

• Plate freezer.
• Blast freezer.
• Low-temperature immersion freezer.
• Still-air cold room.
• Spray freezer.
• Freeze flow.

A very wide variety of foods are frozen, either cooked or in an uncooked state.

Cooked foods: whole cooked meals, braised meat, cream sponges, and puff pastry items.

Raw foods: fillets of fish, fish fingers, poultry, peas, French beans, broad beans, spinach, sprouts, broccoli, strawberries, raspberries, blackcurrant.

With most frozen foods, cooking instructions are given; these should be followed to obtain the best results.

Fillets of fish may be thawed out before cooking; vegetables are cooked in their frozen state. Fruit is thawed before use and as it is usually frozen with sugar the fruit is served with the liquor.

Advantages of using frozen foods.

• Frozen foods are ready prepared, therefore saving time and labor.
• Portion control and costing are easily assessed.
• Foods are always ‘in season’
• Storage is compact.
• Additional stocks are to hand.
• Quality is guaranteed.
• Very little vitamin C is lost from fruits and vegetables even after several months in a deep freeze.