C1f-cooking And Additives Flashcards
Why is cooking food a chemical change?
A new substance is formed
Process cannot be reversed
What is denaturing?
When protein molecules change shape when cooked
Eg eggs and meat
Why does the texture of eggs/ meat change when its cooked?
Shape of protein molecules changed permanently
Why is a potato easier to digest when cooked?
Cell walls rupture resulting in loss of rigid structure and softer texture
Starch grains swell up and spread out
What do antioxidants do?
Stop food from reacting with oxygen
What do food colours do?
Give food an improved colour
What do flavour enhancers do?
Improve flavour of food
What do emulsifiers do?
Help oil and water to mix and not seperate
How does an emulsifier help keep oil and water from separating?
Hydrophilic end(head) bonds with water molecules Hydrophobic end bonds with oil or fat molecules
What is thermal decomposition?
When a substance breaks down into simpler substances when heated
How does baking powder help make cakes rise?
Carbon dioxide is produced which makes the cake rise
What happens when a chemical change takes place?
A new substance is made
Process is irreversible
Energy change takes place
What is the word equation for the decomposition of sodium hydrogencarbonate?
Sodium hydrogencarbonate –> sodium carbonate + carbon dioxide + water
What is the balanced symbol equation for the decomposition of sodium hydrogencarbonate?
2NaHCO3–> Na2CO3+CO2+H2O
