C1F - Cooking & Food Additives Flashcards Preview

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Flashcards in C1F - Cooking & Food Additives Deck (22):
0

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

1

Is cooking food a chemical change. Why ?

Yes because a new substance is formed and the process can't be reversed

2

What stops food from reacting with oxygen ?

Antioxidants

3

Food colours do what ?

Give an improved colour

4

What improves the taste of food ?

Flavour enhancers

5

Emulsifiers help to do what ?

Oil and water to mix instead of separating

6

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

7

How are microbes killed when cooking ?

High temperatures

8

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

9

What happens to protein molecules when you heat them ?

They change shape

10

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

11

Why is it hard for humans to eat a raw potatoe ?

Each cell is surrounded by cellulose which humans can not digest

12

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

13

When you heat baking powder what does it undergo ?

Thermal decomposition

14

Explain the process of thermal decomposition ?

A substance breaks down into a simpler substance when heated. Usually helped along by a catalyst.

15

Why is thermal composition different from a lot of reactions ?

Only one substance to start with

16

What does makes the cake rise ?

Carbon dioxide which is released by thermal decomposition

17

Word equation for thermal decomposition ?

Sodium hydrogencarbonate + Sodium carbonate = Carbon Dioxide + Water

18

How would you check for carbon dioxide ?

It will turn limewater cloudy

19

What parts of emulsifiers love water ?

Hydrophillic

20

What part of emulsifiers love oil ?

Hydrophobic

21

Explain how emulsifiers do their job ?

They keep the oil and water from separating as the hydrophilic end bonds with water and hydrophobic end bonds with oil. Joining them rather than separating.