Processes Flashcards
What does gelatinisation involve?
Starch, heat and moisture
What happens during gelatinisation?
Intermolecular bonds of starch are broken in the presence of water and heat.
At what temperature do starch granules absorb water?
60 degrees
What happens during dextrinisation?
When foods containing starch are cooked by dry heat
What does dextrin contribute?
Flavour of crust
What is caramelisation?
The process of cooking sugar to form burnt and brown sugar
What happens during caramelisation
Texture of sugar changes from crystals to a syrup which cools down and becomes a brittle toffee
What is coagulation?
change in the structure of protein (from a liquid form to solid or a thicker liquid) brought about by heat, mechanical action or acids.
What happens during gluten formation?
Gluten is formed when two classes of water-insoluble proteins in wheat flour (glutenin and gliadin) are hydrated with water and mixed. gluten bonds are formed and a tough rubbery substance is created providing strength and structure.
What is gelatinisation?
process of breaking down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water.
What temperature are starch granules so swollen and start to burst?
80 degrees
What is denaturation?
Chemical bonds have broken and the protein molecule has unfolded and changed shape
What does plasticity mean?
the ability to be spread and shaped
What does butter do to get plasticity?
It creams together with the sugar and other ingred
Why can vegetable fat spreads be easily spread when they are chilled?
Due to the butter and oil, the oil allows the butter to be smoother and more spreadable
Why is the ability of fat to aerate the mixture important?
Creates good texture for the cake
During aeration tiny air bubbles are trapped which makes the mixture expand when heating creating millions of air pockets which gives a light and fluffy texture
What is shortening?
any fat that is a solid at room temperature and used to make crumbly pastry and other food products.
Name the disaccharides
sucrose, lactose, and maltose
Name the monosaccharides
glucose, fructose and galactose
Name the polysaccharides
cellulose, starch and glycogen
How are foams formed?
Liquids become agitated by whisk in/ or beating
This causes proteins to denature
Denatured proteins expand, trapping air in liquids
Coagulation happens - air gets trapped and foam is formed
What causes foams to fall apart?
Over-beating or over-whisking will break coagulation bonds, causing the air to escape and the foam to fall apart
