3.3.1.1.1 Why food is cooked and effects of preparation on food Quiz: AQA Food Preparation and Nutrition, Unit 2

The 20 questions

1. Which of these is a reason food is cooked?

   • To reduce the variety of foods eaten by the family at each meal
   • To remove all the vitamins from the food so that it lasts longer
   • To increase the amount of saturated fat in the food for flavour
   • To make food safe to eat by destroying harmful micro-organisms

2. Which reason for cooking food relates to making it easier to chew and digest?

   • Developing flavour
   • Improving shelf life
   • Improving texture
   • Giving variety in the diet

3. Which effect of cooking on starch helps make a food easier to digest?

   • Starch becomes insoluble in water when heated, so it cannot be digested
   • Starch turns into fat when heated, which makes the food harder to digest
   • Starch is destroyed by heat, so the food contains no carbohydrate after cooking
   • Starch swells and gelatinises when heated, which makes it easier to digest

4. Which change in colour can occur when meat is cooked?

   • It turns from yellow to bright green as the fat is removed
   • It turns from brown to bright blue as the protein dissolves
   • It turns from pink to brown or grey as the myoglobin changes
   • It stays unchanged, because heat has no effect on the colour of meat

5. How does cooking improve the flavour of food?

   • Heat develops flavours through chemical reactions such as browning
   • Heat adds salt to the food, which makes it taste stronger overall
   • Heat adds sugar to the food, which makes it taste sweeter overall
   • Heat removes all flavour from the food by evaporating it into the air

6. Which effect of cooking helps extend the shelf life of a food?

   • Destroying micro-organisms that would cause food to spoil
   • Adding water to the food so that it spoils more slowly
   • Removing all the fat, which reduces the number of spoiling bacteria
   • Increasing the sugar content so that the food stays fresh longer

7. A student cooks a stew for a long time. Which effect is most likely on the meat?

   • The connective tissue breaks down, making the meat more tender
   • The fat turns into starch, which makes the meat firm and tough
   • The protein becomes insoluble, so the meat stays tough and dry
   • The meat loses all its protein, leaving only fat and water

8. Which change happens to a vegetable when it is cooked in water?

   • Cell walls soften and the vegetable becomes easier to chew
   • Cell walls turn into fat, which makes the vegetable greasy
   • Cell walls harden and the vegetable becomes harder to chew
   • Cell walls dissolve completely, leaving no structure in the vegetable

9. Which statement about cooking and appearance is accurate?

   • Cooking never changes the colour of a food, whatever method is used
   • Cooking always makes food paler, because heat removes all colour
   • Cooking can change the colour of food, such as browning bread or roasting meat
   • Cooking only changes the smell of food, not its colour or texture

10. Why does cooking improve the digestibility of protein?

    • Heat denatures protein, which makes it easier for digestive enzymes to act on
    • Heat turns protein into starch, which the body can digest more easily
    • Heat adds fat to protein, which helps the body absorb the protein more quickly
    • Heat removes all protein from the food, so the body digests it more easily

11. A recipe needs a food to be cooked to kill bacteria. Which factor is most important?

    • Cooking at a low temperature for a very short time to keep the vitamins
    • Cooking to a high enough temperature for long enough to destroy bacteria
    • Cooking only in the microwave with the lid left open to keep it dry
    • Cooking in a cold pan for a long time to preserve the fat in the food

12. Which effect of cooking on a food can make it more palatable?

    • Reduced flavour, texture and appearance of the food
    • Reduced aroma and a softer, mushy texture overall
    • Increased bitterness and a dull, grey appearance overall
    • Improved flavour, texture and appearance

13. Explain why cooking vegetables can change their texture.

    • Heat hardens the cell walls and starch, so the vegetable becomes firmer
    • Heat removes the water from the vegetable, which makes it crisp and hard
    • Heat dissolves the vegetable fibre completely, leaving only the juice behind
    • Heat softens the cell walls and starch, so the vegetable becomes less firm

14. Which food is safer to eat after cooking, because micro-organisms are destroyed?

    • Chicken cooked until it is no longer pink and the juices run clear
    • Eggs cooked until the yolk is runny and the white is still transparent
    • Chicken eaten raw with the juices still pink and blood-red
    • Minced meat left pink in the middle after a short cooking time

15. Why is it important to cool cooked food quickly?

    • To make the food less nutritious so that it is safer to store
    • To prevent bacteria multiplying in the food, which would make it unsafe
    • To remove the flavour from the food so it is more neutral in taste
    • To increase the number of bacteria so the food develops a stronger flavour

16. Which of these is a reason that cooking increases the variety of a diet?

    • Cooking allows many different foods to be prepared, such as grains, meat and pulses
    • Cooking removes the flavour from food so that all foods taste the same
    • Cooking limits all foods to one type of preparation, which lowers the variety
    • Cooking reduces the number of foods that can be eaten, which lowers the variety

17. Explain why cooking can make food safer to eat.

    • Heat destroys harmful micro-organisms and their toxins, reducing the risk of food poisoning
    • Heat increases the number of micro-organisms in the food, so the body builds up immunity
    • Heat adds nutrients to the food, which strengthens the body's defence against germs
    • Heat removes the flavour from the food, so there is less reason to eat it

18. Which effect of cooking on protein in an egg is a change in its structure?

    • Converting, which makes the egg white turn into starch
    • Denaturation, which makes the egg white set and become firmer
    • Dissolving, which makes the egg white turn into a thin fat
    • Condensing, which makes the egg white disappear completely

19. Which effect of cooking can improve the digestion of food?

    • Removing all protein, which leaves food that is harder to digest
    • Removing all fibre, which makes food harder to chew and digest
    • Softening tough food, which makes it easier to chew and digest
    • Hardening food, which makes it much harder to chew and digest

20. Which statement about cooking and nutrients is accurate?

    • No nutrients are ever lost in cooking, whatever method or time is used
    • Cooking adds nutrients to food so the nutritional value always increases
    • All nutrients are always lost in cooking, so cooking should always be avoided
    • Some nutrients are lost in cooking, so the method chosen affects the final nutritional value

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