Chapter 15 - The Science Behind Food Preparation and Cooking Flashcards
Explain the changes which take place when the cake is baking.
● Raising action takes place during baking. Air was
incorporated into the mixture during the cake-making
process [E.g creaming process.]
● This air, together with steam produced during the
baking process will expand the volume of the cake
during baking.
● As the gas expands, gluten from the flour in the
dough will stretch the dough and together with the
egg proteins, will hold the expanding particles
together.
● Moisture will evaporate as a result of the baking
which will lead to a firm structure.
Identify and describe a food science reaction that will occur when the shortcrust pastry is being baked in the oven.
● Dextrinisation
The process in which starch molecules is in contact with dry
heat. Starch molecules will be broken down into dextrins.
It will produce a toasted aroma and the dextrins will leave a brown surface. Process is irreversible.
Define coagulation.
Coagulation is a reaction in which proteins change from a liquid state to a semi-solid or solid state, in the presence of heat, pressure or acids.
Example: boiling egg
100g self-raising flour
100g butter
100g caster sugar
2 eggs
Name the cake-making method which would be used based on the recipe above
Creaming method
100 g plain flour 60 g egg, beaten 250 ml milk ¼ tsp salt ¼ tsp turmeric powder
State the type of batter used to make the Roti Jala.
Thin batter
● Plain flour- helps to provide structure / sets the shape of the batter
● Egg- helps to increase the volume of the batter
● Milk- Contribute to fluidity/ consistency of the batter
Suggest two reasons with examples for using batter.
● To coat and prevent food from breaking up
[Eg. Coating fish fillet with thick batter before frying the fish to make Fish Fillet.]
● To coat and prevent loss of nutrients due to the intense heat of frying food [Eg. Coating banana with thick batter to make Banana Fritter.]
Define the term smoking point and give one example.
The temperature at which fat breaks down into glycerol and fatty acids.
Example: Butter has a lower smoking point than sunflower oil.
Define the term melting point and give one example.
The temperature at which solid fats melts.
[Eg. Butter when cooked will melt into liquid butter.]
Define the term emulsion and give example.
Mixing 2 immiscible liquids together, through vigorous shaking immiscible liquids such as water and oil which do not mix.
An unstable emulsion can be stablised by adding an emulsifier. [Eg. is mayonnaise, creamy salad dressing or whole milk, butter, margarine.]
Give three reasons for including sauces and give an example for each.
- To improve flavor of a dish. [Eg. sauce on boiled pasta]
- To improve the appearance of the dish by adding colour. [Eg. Sauce on grilled fish or steamed tofu]
- To counteract the richness of food. [Eg. mint sauce on roasted lamb]
Explain how the process of gelatinisation occurs when the sauce is cooked.
Heating of starch in liquid, starch granules absorb the liquid swell and burst, releases starch into surrounding liquid, causes liquid to thicken.
Name the two type of sauce.
Roux sauce and blended sauce.
What is the difference between light roux and dark roux.
Light roux is used for making which sauce (Bechamel sauce) while dark roux is used for making brown sauce.
What is a blended sauce.
A blended sauce is thickened with starch such as corn starch or potato starch.
Example of blended sauces are sweet and sour sauce and custard sauce.
What is a roux sauce.
Roux sauce is made from cooked flour and fat mixture called roux. The sauce is made with equal quantities of fat and wheat flour. The fat is melted before flour is mixed in. The mixture must be stirred constantly during cooking to prevent the sauce from burning.
