Credit Hygiene Homework/Revision
KNOWLEDGE AND UNDERSTANDING QUESTION 6 MARKS
3.
(b) The social club are holding an annual barbecue.
Identify and explain three points of advice they should follow to
reduce the risk of food poisoning.
Point of advice 1 _______________________________________________
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Explanation ___________________________________________________
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Point of advice 2 _______________________________________________
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Explanation ___________________________________________________
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Point of advice 3 _______________________________________________
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Explanation ___________________________________________________
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Question 3 (b)
Points of advice to reduce the risk of food poisoning
Defrosting
Point
• Defrost meat/poultry/fish/burgers/sausages/kebabs thoroughly.
Explanation
• If not defrosted then the food may not reach a high enough temperature to kill
harmful bacteria in the centre (leading to food poisoning).
• Barbecued food may burn on the outside and still be raw in the centre not
destroying harmful bacteria (leading to food poisoning).
Storage
Point
• Keep food out of the danger zone/below 5ºC and above 63ºC before cooking/
once cooked/after cooking.
Explanation
• Bacteria multiply rapidly in the danger zone which could lead to harmful
bacteria multiplying (that may cause food poisoning.)
Point
• Keep perishable foods in the refrigerator/cool box below 5ºC until ready for
preparing/cooking/serving.
Explanation
• To keep food cool to prevent bacteria multiplying (leading to food poisoning).
Point
• Cover all foods until ready for serving/keep raw meat in sealed container away
from ready to eat food.
Explanation
• Flies, insects, birds, pets may spread harmful bacteria onto food (leading to food
poisoning).
• Harmful bacteria may enter food (and lead to food poisoning).
• To prevent cross contamination.
Point
• Keep raw and cooked foods separately/keep raw meat away from ready to eat
food/don’t put cooked food on surface used for raw meat/store raw meat at
bottom of fridge.
• Wash salads/fruits/vegetables before use.
Explanation
• To avoid the spread of harmful bacteria (leading to food poisoning).
• To prevent cross contamination (from raw to cooked food).
Point
• Check use by dates on perishable foods.
Explanation
• To ensure bacterial count is within acceptable levels.
Page 18
CREDIT LEVEL
Question (b) continued
Cooking
Point
• Cook food thoroughly/to at least 75ºC or above/use temperature probe to check
centre of food is at least 75ºC/turn food regularly and move around the barbecue
to cook evenly/until juices run clear.
Explanation
• Kill any harmful bacteria (that may cause food poisoning).
• This will kill any harmful bacteria (that may cause food poisoning).
Reheating
Point
• Reheat food only once.
• Reheat food to 82ºC (for at least 2 minutes).
Explanation
• Harmful bacteria will have multiplied and may not be destroyed if food is heated
more than once.
Utensils
Point
• Use separate utensils/chopping boards/knives for raw and cooked food.
Explanation
• To avoid the spread of harmful bacteria (leading to food poisoning).
• To prevent cross contamination (from raw to cooked food).
Food handlers
Point
• Ensure food handlers wash hands/use anti-bacterial gel/wipes between touching
raw and cooked food/visiting toilet/touching bins.
Explanation
• To avoid the spread of harmful bacteria (leading to food poisoning)/to prevent
cross contamination.
Point
• Ensure food handlers follow rules on personal hygiene/wear a clean apron when
preparing/cooking/serving food at the barbecue.
Explanation
• To prevent the food becoming contaminated with harmful bacteria (which could
lead to food poisoning).
CREDIT LEVEL
Question 3 (b) continued
Point
• Food handlers preparing/cooking/serving food should not be suffering from
infections/diarrhoea.
• Food handlers should cover cuts with a waterproof dressing.
Explanation
• This could lead to harmful bacteria being transferred from the food handler to
the food (leading to food poisoning).
Point
• Ensure food handlers follow kitchen hygiene rules/use clean equipment/change
cloths regularly.
Explanation
• To prevent cross contamination.
Leftovers
Point
• Cool leftovers as quickly as possible, cover and refrigerate.
Explanation
• To prevent entry of harmful bacteria/prevent multiplication of harmful bacteria
(which may lead to food poisoning).
ONE MARK for each of three points of advice.
ONE MARK for each of three explanations.
TOTAL SIX MARKS
.
Q2 KU 4 MARKS
(a) Give two explanations how each of the following methods of preservation
prevent food spoilage.
(i) Freezing
Explanation 1 _______________________________________________
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Explanation 2 _______________________________________________
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(ii) Pickling
Explanation 1 _______________________________________________
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Explanation 2 _______________________________________________
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Explanation of
methods of food
preservation
(i) Freezing
Explanations:
• Initial blanching
retards the activity of
enzymes
• Freezing reduces the
temperature of food to
at least -18ºC/very cold
where
microbes/bacteria are
dormant (and cannot
spoil the food)
• During freezing, the
water in food is turned
to ice so bacteria
cannot multiply (and
cause
decay/deterioration)
• The process of
freezing causes
bacteria to become
dormant.
(ii) Pickling
Explanations:
• Initial boiling of the
ingredients will
destroy enzymes/micro
organisms (but not
spores)
• The high
concentration of
acid/vinegar prevents
growth of
yeast/bacteria
• The low pH inhibits
bacterial growth
• The initial high
concentration of salt
inhibits micro
organisms
• Sterilising the pickle
jars before use destroys
micro organisms
• Sealing the pickle
jars prevents
recontamination of the
food by bacteria (from
the atmosphere).
ONE MARK for each
of two explanations
relating to how each
method of preservation
prevents food spoilage.
TOTAL FOUR
MARKS
Q3 KU 6 MARKS
(c) Identify and explain three conditions that affect bacterial growth in food.
Condition 1
Explanation
Condition 2
Explanation
Condition 3
Explanation
Conditions that affect Bacterial Growth
Condition: Temperature/warmth/freezing/boiling
Explanation
• Bacteria need temperatures between 5° − 63°C to multiply/room temperature.
• At temperatures below 5°C growth of bacteria is slowed down.
• At temperatures below -18°C (domestic freezer) bacteria become dormant/cannot
multiply/freezing temperatures (but not if freezing is stated as a condition).
• At temperatures above 63°C most bacteria is destroyed.
Condition: Food
Explanation
• Food that contains high amounts of protein supports the multiplication of
bacteria.
Condition: Moisture
Explanation
• Bacteria cannot multiply in dry food/need moist food.
• Preserving methods such as freezing/drying/pickling/jam making/salting make
the moisture unavailable to the bacteria and thereby prevent its ability to
multiply.
Condition: Time
Explanation
• Bacteria require time if they are to multiply if other conditions are ideal/right.
• One bacterium can split into two every 10 minutes/quickly/binary fission.
Condition: Oxygen
Explanation
• Some bacteria require oxygen if they are to multiply.
• Aerobic bacteria need oxygen to multiply.
• Anaerobic bacteria do not need oxygen to multiply.
Condition: pH/acidic
Explanation
• Most bacteria prefer neutral conditions/between pH 6.6 and pH 7.5.(accept pH 7)
• Bacteria will not multiply in very acidic conditions/alkaline conditions (only
accept if pH is condition)
ONE MARK for each three correctly identified conditions affecting bacterial
multiplication.
ONE MARK for each of three correct explanations.
TOTAL SIX MARKS