Fats And Oils - Food Properties Flashcards
What is plasticity?
The ability of fat to soften over a range of temperatures and be shaped and spread with light pressure.
What is shortening?
The ability of fats to shorten the length of gluten molecules in pastry.
What is aeration?
The ability of fats to trap lots of air bubbles when beaten together with sugar.
What is emulsification?
Keeping drops of oil or fat suspended in a liquid and preventing them from separating out.
What does the plasticity of fats enable us to do?
Spread raw cake mixtures into a cake tin, piping buttercream onto cakes, spreading cream cheese onto cracker.
Why are fats plasticible?
Their chemical structure: they are composed of different triglycerides, containing different fatty acids. The triglycerides all have different melting points.
Finish the sentence:
The more unsaturated fatty acids a fat contains…
…the less solid it is and the less plasticity it has.
Why do ‘short’ dough mixture have a very crumbly texture when baked?
They have a high fat content, which is mixed in with the flour to prevent the gluten from forming long molecules.
Why are the fingertips used to rub the fat into a shortcrust pastry mix?
They are the coolest part of the body so won’t melt the fat.
What happens to the flour particles when the fat is rubbed in to a shortcrust pastry mixture?
They are coated with a waterproof fat layer.
What do the waterproof layers of fat surrounding the flour particles do in shortcrust pastry mixture?
When cold water is added to bind it together, the waterproof layers of fat prevent the formation of long gluten molecules (only short ones can form).
Why do we want short gluten molecules in pastry dough?
So that it is not stretchy and doesn’t spring back when rolled out like bread dough.
