Flashcards in C1F - Cooking & Food Additives Deck (22):
What happens if a chemical change takes place ?
1) There is a new substance made
2) The process is irreversible
3) An energy change takes place
Is cooking food a chemical change. Why ?
Yes because a new substance is formed and the process can't be reversed
What stops food from reacting with oxygen ?
Food colours do what ?
Give an improved colour
What improves the taste of food ?
Emulsifiers help to do what ?
Oil and water to mix instead of separating
Why would we need to cook food ?
1) better taste and texture
2) easier to digest
3) killing of microbes
4) some foods are poisonous when raw
How are microbes killed when cooking ?
Why can't we eat red kidney beans raw ?
They contain a poison that's only killed by at least 10 minutes of boiling and 2 hours cooking
What happens to protein molecules when you heat them ?
They change shape
Explain the denaturing process with proteins.
Energy from cooking will break some of the chemical bonds in the protein. Allowing it to change shape. This gives a more edible texture
Why is it hard for humans to eat a raw potatoe ?
Each cell is surrounded by cellulose which humans can not digest
How does cooking the potatoe help us to digest it ?
It ruptures the cell wall making it loose its rigid structure and have a softer texture and it makes the starch grains swell up and spread out making it easier to digest
When you heat baking powder what does it undergo ?
Explain the process of thermal decomposition ?
A substance breaks down into a simpler substance when heated. Usually helped along by a catalyst.
Why is thermal composition different from a lot of reactions ?
Only one substance to start with
What does makes the cake rise ?
Carbon dioxide which is released by thermal decomposition
Word equation for thermal decomposition ?
Sodium hydrogencarbonate + Sodium carbonate = Carbon Dioxide + Water
How would you check for carbon dioxide ?
It will turn limewater cloudy
What parts of emulsifiers love water ?
What part of emulsifiers love oil ?