Changing Properties- Proteins

Question 1

When food is cooked proteins ……….

Answer 1

Denature, unravel and changes shape.
Can be denatured in different ways:
Physical agitation 
Temperature change 
Acids

Question 2

Denatured protein molecules ………

Answer 2

Coagulate

Denatured proteins collide with other protein molecules and coagulate.
This allows water to become trapped between the molecules.
Changes appearance and texture of the food.
If overcooked the proteins tighten which forces water out so becomes dry an chewy

Question 3

Foams are formed when……..

Answer 3

Air is trapped.
Liquids containing protein become agitated and denature.
This stretches the protein and air becomes trapped through coagulation.

Over whisking can break the new bonds and the air escapes and the foam collapse.

Question 4

Gluten allows doughs to ………

Answer 4

Stretch and rise.
Gluten is formed when water is added to the flour to make the dough.
Molecules of gluten are coiled and are able to bend and stretch which gives elasticity.
Doughs are kneaded to work the gluten which causes the strand to get longer, stronger and stretchier.
At a high temperature the gluten coagulates and the dough stays stretched.