3.3.2.2 Gelatinisation, dextrinisation and caramelisation Quiz: AQA Food Preparation and Nutrition, Unit 2

The 20 questions

1. What is gelatinisation in starch cookery?

   • Starch molecules break into smaller dextrin chains when toasted in a dry oven
   • Starch granules absorb liquid and swell when heated, thickening the mixture
   • Proteins unfold and link together, setting the mixture into a firm, cut gel
   • Sugars heat until they brown and form a bitter caramel flavour in the pan

2. Which term describes starch breaking down into dextrins under dry heat?

   • Coagulation
   • Dextrinisation
   • Gelatinisation
   • Caramelisation

3. What is caramelisation?

   • Sugars heated until they break down and brown, producing new flavours
   • Fat crystals melting and trapping air bubbles inside the cake batter
   • Protein molecules unfolding and joining to form a firm, set network
   • Starch granules absorbing water and swelling into a thick, glossy paste

4. When a roux is made, why must the liquid be added gradually and whisked in?

   • So the sugar caramelises evenly across the whole sauce at once
   • So the fat emulsifies completely before the starch is able to swell
   • So the proteins denature fully before the fat has a chance to melt
   • So the starch granules swell evenly without lumps forming

5. A sauce is made with 50g of cornflour to 300ml of liquid, and another with 25g. Which will be thicker?

   • The 25g sauce, because starch dilutes the liquid and makes it richer
   • The 50g sauce will caramelise in the pan and turn brown and sticky
   • Both will be the same, because the starch fully dissolves in either one
   • The 50g sauce, because it has more starch for the same volume of liquid

6. A cook heats sugar in a dry pan and it turns amber. What has happened?

   • The sugar has emulsified with air and produced a light, stable foam
   • The sugar has gelatinised into a thick starchy gel in the pan
   • The sugar has caramelised, producing brown colour and new flavour compounds
   • The sugar has denatured and coagulated into a set, protein-like mass

7. Bread browns and forms a crust in a hot oven. Which process is mainly responsible for the surface colour?

   • Coagulation of the egg protein on the outside of the loaf
   • Dextrinisation of the starch on the outside of the loaf
   • Hydrolysis of the protein on the outside into free amino acids
   • Emulsification of the butter fat on the outside of the loaf

8. At what approximate temperature range does starch gelatinise in a liquid?

   • Roughly 60°C to 80°C
   • Roughly 0°C to 5°C
   • Roughly 100°C to 120°C
   • Roughly 20°C to 30°C

9. Why can carrots caramelise when they are cooked in a little fat in a hot pan?

   • They contain fat that emulsifies with water when heated in a pan
   • They contain starch that dextrinises when it is simmered in cold water
   • They contain protein that coagulates into a firm, glossy glaze on the surface
   • They contain natural sugars that brown when heated strongly in dry conditions

10. A carrot glaze is made by heating carrots with butter and sugar until golden. Which process gives the glaze its flavour?

    • Gelatinisation of the carrot starch
    • Denaturation of the carrot protein
    • Caramelisation of the sugars
    • Shortening action of the butter fat

11. Why does a gravy thicken and turn glossy when cornflour is stirred in and brought to the boil?

    • The sugar caramelises and forms a dark coating on the surface of the gravy
    • The fat emulsifies and forms a cream that coats the back of a spoon
    • The protein coagulates and sets the liquid into a light, firm jelly
    • The starch granules gelatinise and swell, binding the liquid together

12. Which of these is an example of dextrinisation in cookery?

    • Whisked egg white becoming stiff and white in a bowl
    • A custard setting after being heated gently in a water bath
    • Toast turning golden brown when it is made under a hot grill
    • Mayonnaise thickening as oil is added slowly to the egg yolk

13. Which factor mainly controls the thickness of a starch-based sauce?

    • The colour of the saucepan that is used
    • The time of day when the sauce is made
    • The type of dish the sauce is served in
    • The ratio of starch to liquid

14. Why is a flour roux cooked for a short time before the liquid is added?

    • It removes the raw floury taste and develops a nutty colour
    • It emulsifies the fat so that the finished sauce stays smooth
    • It caramelises the flour sugars into a sweet, thick syrup
    • It denatures the flour protein into a firm gel before mixing

15. Why is a starch sauce cooked gently at a simmer rather than boiled hard?

    • Gentle heat denatures the starch so that the sauce sets firmly in the pan
    • Gentle heat emulsifies the starch with fat into a stable, layered sauce
    • Gentle heat caramelises the starch and gives the sauce a rich brown colour over time
    • Gentle heat fully gelatinises the starch and keeps the sauce thick and smooth

16. Why does caramelised sugar taste bitter if it is overheated?

    • Sugar emulsifies with the fat, releasing a bitter oily layer on the surface of the sauce
    • Sugar starts to gelatinise and forms a bitter, starchy paste in the pan
    • Sugar breaks down into compounds that taste bitter and burnt at high temperature
    • Sugar denatures and releases bitter protein fragments into the syrup

17. Which two starch processes are both used in cookery?

    • Gelatinisation and dextrinisation
    • Caramelisation and emulsification
    • Gelatinisation and coagulation
    • Dextrinisation and denaturation

18. Which cooking method most suits dextrinising starch on a flour-based crust?

    • Poaching in gently moving liquid
    • Steaming above a pan of boiling water
    • Simmering in a covered pan of water
    • Baking in a dry oven

19. What do caramelisation of sugars generally need?

    • Vigorous whisking to trap air bubbles inside the syrup
    • Dry, high heat that breaks the sugar down and browns it
    • A long soak in cold water to dissolve the sugar fully
    • A little acid added to make the sugar set into a firm gel

20. A flour-thickened sauce is to be smooth. Which order of steps is best?

    • Add the dry flour straight into boiling liquid, stir once, then cool it
    • Mix the flour with melted sugar, then add cold fat and whisk until firm
    • Heat the dry flour in a pan until brown, then add it to cold liquid
    • Mix the flour with a little cold liquid, then add it to hot liquid while stirring

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