Carbohydrates - Food Properties Flashcards
What are the two groups of carbohydrates?
Sugars and complex carbohydrates.
What is gelatinisation?
The swelling of starch granules when they are cooked with a liquid to the point where they burst and release starch molecules.
What is dextrinisation?
The breaking up of starch molecules into smaller groups of glucose molecules when they are exposed to dry heat.
What is caramelisation?
The breaking up of sucrose molecules when they are heated, which changes the colour, flavour and texture of the sugar as it becomes caramel.
Why is gelatinisation not included in this set?
It has its’ own set! Go revise it after this!
What is the effect of heat on starch molecules?
They break into smaller groups of glucose called dextrin.
What are carbohydrates made up of?
Carbon, hydrogen and oxygen.
What has happens when toast turns black?
It has gone past the dextrinisation stage: the oxygen and hydrogen have been evaporated by the heat as water and all that is left is carbon.
What is the first thing that happens when sugar is heated?
It melts, then forms a syrup and boils.
What happens as a sugar is boiling?
The molecules of sucrose start to break up.
Why does sugar change colour?
The hydrogen and oxygen atoms form water and evaporate. The colour of sugar will eventually turn black as this is the colour of carbon.
Why must you not stir a syrup as it caramelises?
It will crystallise into large, hard lumps.
What is the temperature of caramelising sugar?
160-170 degrees Celsius.
How would you get the sugar to come out of a onion and caramelise?
You would sautée or roast the onion in oil or fat.
