Download Answers for S3 Credit Hygiene Assessment

Answers for S3 Credit Hygiene Assessment
KNOWLEDGE AND UNDERSTANDING
2.
(b) Identify two rules to follow when freezing food.
Explain why each rule is important for the food.
Rule 1 ___________________________________________________________
_________________________________________________________________
Explanation ______________________________________________________
_________________________________________________________________
_________________________________________________________________
Rule 2 ___________________________________________________________
_________________________________________________________________
Explanation ______________________________________________________
_________________________________________________________________
Question 2 (continued)
(b) Two rules to follow when freezing food
Rule
Explanation
• Use suitable packaging materials to
wrap the food
• This will help to prevent damage to
the food/may cause dehydration/
freezer burn
• Helps reduce spoilage of food
• Remove as much air as possible from
the package before freezing
• This will help to prevent oxidation/
damage of the food
• Do not place hot food in the freezer/
cool food before freezing
• Placing hot food in the freezer will
raise the temperature/may cause
bacteria to start multiplying
• Ensure the freezer is working below
-18°C (by using a thermometer)
• This will ensure that the food stays at
a point where microbial activities
cease/bacteria is dormant (so stays
safe to eat)
• This will ensure that the natural decay/
deterioration of the food is halted for a
considerable time
• Do not overload the freezer • Cold air needs to circulate around the
food
• Never refreeze food that has been
thawed (unless they have undergone a
cooking process)
• When the food is thawing, bacterial
growth will increase
• When you refreeze the food you are
refreezing the food which has an
increased bacteria content present
• Label foods with contents/date • Enables you to identify foods/check
storage times/use foods in rotation
• Read labels on prepacked food/check
suitability for freezing
• To ensure good quality/prevent waste
• To prevent food poisoning
• Freeze as quickly as possible/fast
freeze
• To retain texture/quality
• Blanch fruit/vegetables if required • To destroy enzymes/prevent food
spoilage
ONE MARK for each of two rules to follow when freezing food.
ONE MARK for each correct explanation.
TOTAL FOUR MARKS
Extra Esssential Knowledge
To achieve good results food must be frozen fast to below -18’C to preserve its
original colour, flavour and texture.
If food is frozen slowly, large ice crystal form. These expand during freezing, puncture
cell walls and destroy surrounding tissue. On thawing the nutrients are lost through
punctured cells, making food flabby and discoloured. So the faster the food is frozen, the
smaller the ice crystals and the more perfect the structure of the food.
The fast-freeze switch (also known as auto-freeze, super-freeze) enables the freezer motor
to override the thermostat. As a result, the temperature continues to fall as low as -24’C so
that fresh food can be frozen solid without raising the temperature of the already frozen
foods inside. This prevents a fluctuation of temperature and large crystals forming in the
already-frozen food.
Freezing Vegetables
Vegetables with a high water content such as tomatoes, salad greens, white cabbage must
be cooked before freezing. For long term storage you should first of all blanch vegetables.
This is necessary to stop enzymes working, which cause food spoilage and loss of flavour
and colour, even when frozen. To blanch broccoli , place heads in a wire basket and
plunge into fast boiling water for 3 minutes. Remove and plunge into ice-cold water or
under cold water tap for 3 minutes. Drain well, open freeze (place on plastic tray or foilline baking tray, spreading vegetables out so that they do not touch.) Fast-freeze until
solid, remove from the freezer, pack quickly into polythene bags or rigid containers, seal,
label and return to freezer.
Freezing Fruit
Use high quality fruit – must be ripe, and free from bruises and blemishes.
Two basic methods of preparing fruit are:1. Free flow or open freeze packing – good for raspberries. Method see above.
Advantage: The berries remain separated. You can remove a small amount of frozen
fruit without having to thaw the whole quantity.
2. Dry sugar pack –good for soft, juicy, whole or sliced fruit. Layer fruit and sugar
In a rigid container. Leave room for expansion. In thawing the fruit and sugar
will make its own syrup.
Discolouration (Enzymic browning) – can be prevented by addition of Vitamin C. Steep
sliced apples in a lemon juice and water solution. Pat dry before packing with sugar.
Effective Packaging for freezing food
For long periods of storage, packaging needs to eliminate as much air as possible and seal
the food so that it is protected from contamination when taken from the freezer to thaw
(defrost).
Dehydration will take place if food is insufficiently wrapped, as much air as possible is not
excluded, and if the food is stored for too long. It is therefore important to label and date
food.
Freezer burn is a brown or grey-ish white patches on the surface of frozen food. This is
caused by extreme dehydration which causes the tissues to go tough and spongy.
Oxidation may occur in meats and fish with a high fat content. Oxygen penetrates animal
tissues causing the fat to oxidise and go rancid. This can give the food an unpleasant “off”
smell. Salt will also cause this so foods such as bacon or butter have short storage lives.
Cross-flavourings. Highly flavoured foods such as garlic bread and onions, can, if not
properly wrapped transfer their smell and flavour to other items in the freezer. Always
double wrap in heavy-duty foil or place in a polythene bag.
Q2 KNOWLEDGE AND UNDERSTANDING
8 MARKS
Some pieces of information must appear on a food label by law.
Identify four of these pieces of information and explain their
importance to the consumer.
Information 1 ____________________________________________________
Importance ______________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_______________________________________________________________
Information 2 ____________________________________________________
Importance ______________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Information 3 ____________________________________________________
Importance ______________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Information 4 ____________________________________________________
Importance ______________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_______________________________________________________________
Answer Scheme for this SQA question is
Home Economics
Credit Paper 2008
Question 2 (c)
http://www.sqa.org.uk/pastpapers/findpastpaper.htm
?subject=Home+Economics