3.4.1.1.2 High risk foods and control of microorganism growth Quiz: AQA Food Preparation and Nutrition, Unit 3

The 20 questions

1. What is a high-risk food?

   • A ready-to-eat, moist food high in protein that supports bacterial growth and needs no further cooking
   • A sugar-rich confectionery that is kept sealed in a cupboard and stays safe for a whole year
   • A dry food low in protein that can be kept at room temperature for many months without spoiling
   • A raw vegetable that is always washed thoroughly and then eaten without any preparation or cooking

2. Which of these is a high-risk food that must be chilled promptly after cooking?

   • Plain sugar kept in a jar on a dry kitchen shelf
   • Cooked chicken that is ready to eat
   • Dried pasta stored in a sealed box in a cupboard
   • Whole uncut melon kept in a fruit bowl on the side

3. Which of these is a high-risk food that should be cooled and refrigerated quickly after cooking?

   • Cooked rice
   • Plain flour in a bag
   • Dried lentils stored in a sealed jar
   • Whole uncut melon

4. Why should cooked meat be cooled and refrigerated quickly?

   • So enzymes can caramelise the meat surface while it sits in the fridge
   • So bacteria do not multiply in the warm, moist meat while it cools
   • So the fat can emulsify and make the meat moister when it is served
   • So the protein can gelatinise and set firm in the cold environment

5. Cream-filled desserts are served after a long time out of the fridge. What is the main concern?

   • Bacteria may have multiplied to unsafe levels in the moist, high-protein dessert
   • Sugar may have crystallised and made the dessert too hard to eat
   • Starch may have dextrinised and turned the dessert gritty and dry
   • Fat may have caramelised and turned the cream an unappealing brown

6. Which action controls micro-organism growth by adjusting pH?

   • Increasing the time a food stays at room temperature before serving
   • Heating a food to just above freezing point for storage
   • Adding acid such as vinegar or lemon juice to the food
   • Adding extra water to the food to dilute it in the pan

7. What is the most effective way to keep high-risk food safe during service?

   • Keep the food warm at about 30°C and let it stand for several hours on the bench
   • Keep the food at room temperature in a sealed bowl overnight
   • Keep cold food below 5°C and hot food above 63°C, and serve it promptly
   • Keep the food in a dry cupboard at around 20°C for a whole week

8. What is the main reason for covering cooked food while it cools?

   • To stop bacteria and pests from the air reaching the food as it cools
   • To stop the fat from emulsifying into the surrounding liquid as it cools
   • To stop the protein from gelatinising in the bowl as it cools
   • To stop the food from caramelising on its surface as it cools

9. A stew made in advance is reheated for service. What should be done?

   • Heat it only until the top is steaming, then serve it at once
   • Reheat it to 50°C and hold it for several hours before serving at the table
   • Warm it gently to about 40°C so that it stays soft and tender
   • Reheat it until the centre reaches 75°C throughout before serving

10. Why should cooked food not be reheated more than once?

    • Each reheating denatures the protein, which then becomes indigestible
    • Each reheating makes the starch dextrinise into a crunchy, dry crust
    • Each reheating and cooling gives bacteria time to multiply
    • Each reheating dissolves the fat, which then separates from the food

11. Why is cooked egg custard considered a high-risk food?

    • It is moist and high in protein, so bacteria can grow in it
    • It is dry and high in starch, so bacteria cannot grow in it
    • It is high in sugar and low in water, which stops micro-organisms
    • It is acidic with a pH below 2, so bacteria cannot survive in it

12. Which of these is a safe way to serve high-risk food on a buffet?

    • Leaving cooked meat uncovered on a worktop overnight to cool slowly
    • Keeping hot food above 63°C in a hot-holding unit
    • Leaving cold food on the buffet table at room temperature for hours
    • Holding salad in a warm room to soften it before the guests arrive

13. Why should cooked food be cooled quickly rather than left out to cool?

    • So the proteins can coagulate more firmly at a lower temperature
    • So the fat can emulsify and set the food into a firm block
    • So the starch can gelatinise fully as it cools into a thick gel
    • So it passes through the danger zone quickly, which limits bacterial growth

14. Why is uncovered gravy left in a warm pan at risk?

    • Contamination from the air and slow cooling keep it in the growth range for longer
    • Uncovered gravy gelatinises its starch, which feeds the bacteria more readily as it cools
    • Uncovered gravy caramelises on its surface, which feeds bacteria on the top
    • Uncovered gravy absorbs fat and emulsifies, which speeds up bacterial growth

15. Which storage action gives the best control of bacteria in high-risk food that must be kept cold?

    • Storing it at 30°C in a warm cupboard with a towel placed over it
    • Storing it at 10°C in a cool room with the fridge door left open
    • Storing it at 20°C in the kitchen with the bowl left uncovered
    • Storing it at 0 to below 5°C in a correctly running fridge

16. Why does acid not make a high-risk food completely safe on its own?

    • Acid destroys the protein so that the food can no longer be digested
    • Acid turns bacteria into enzymes, which then spoil the food from within
    • Some bacteria tolerate acid and can still grow, so cooking and chilling are still needed
    • Acid speeds the growth of all bacteria, which makes the food more dangerous

17. Why should raw meat be stored below cooked foods in a fridge?

    • To keep the raw meat warmer than the cooked food on the same shelf
    • To stop drips of raw meat juice contaminating the cooked food
    • To allow the enzymes in the raw meat to caramelise slowly
    • To stop the fat in the raw meat emulsifying with the cooked food

18. A cook uses the same chopping board for raw chicken and cooked salad. Which principle is broken?

    • Separating raw and cooked foods to avoid cross-contamination
    • Using a temperature probe to check that the food is cooked
    • Keeping the food cold below 5°C in the fridge at all times, including during the whole working day
    • Reheating food to 75°C before it is served to the guests

19. Which food is not typically classed as high-risk?

    • Cooked egg custard kept at room temperature after making
    • Cooked rice left out for several hours at room temperature
    • Dry, uncooked rice stored in a sealed box
    • Cooked meat left on a warm buffet for the afternoon

20. Which storage gives the lowest risk for a prepared salad that is served the next day?

    • Covered in a warm kitchen at around 25°C overnight
    • Covered and kept in a fridge below 5°C, then eaten the same day
    • Uncovered in a bowl on the buffet for most of the afternoon in a warm room
    • Uncovered on a warm bench for several hours before serving

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