6 Plant Oils

Question 1

Why are vegetable oils important foods?3

Answer 1

• they provide nutrients
• and have a high energy content
• different flavours

Question 2

What are unsaturated oils and how do we detect them?

Answer 2

• unsaturated oils contain carbon-carbon double bonds

- we can detect them as they de colorise bromine water

Question 3

What are the advantages of cooking with vegetable oils?4

Answer 3

• food cooks quicker
• the food turns a different colour
• the food becomes crispier
• the inside food is softer if you don’t cook it for too long

Question 4

why would frying with vegetable oils become more unhealthy?

Answer 4

• the energy content of fried food is much higher so regularly eating it would be unhealthy

Question 5

How do we turn vegetable oils into spreads?2

Answer 5

• vegetable oils are hardened by reacting them with hydrogen to increase melting points
• this makes them solids at room temperature which are suitable for spreading

Question 6

What are the boiling points of vegetable oils compared to normal foods?

Answer 6

Higher

Question 7

Do oils dissolve in water?

Answer 7

No

Question 8

What is an emulsifier?

Answer 8

Emulsifier stops oil and water from separator out into layers

Question 9

How do emulsifiers work?

Answer 9

• Because one part of its molecule dissolves in oil ( the hydrophobic part )
• one part dissolves in water ( the hydrophilic part )

Question 10

What are smooth foods generally made from?

Answer 10

A mixture of oil and water

Question 11

What is an emulsifier?

Answer 11

A substance which keeps immiscible liquids mixed so that they do not separate out into layers

Question 12

Why are emulsions made from vegetable oils so important?4

Answer 12

They are used in many foods such as salad dressings, ice creams, cosmetics and paint

Question 13

What are the benefits of vegetable oils?

Answer 13

• vegetable oils are high in energy and provide nutrients
• they are unsaturated and believed to be better for your health
• than saturated animal fats and hydrogenated vegetable oils

Question 14

What are the benefits and drawbacks of using emulsifiers?2

Answer 14

• they improve the texture of foods enabling water and oil to mix
• this makes fatty foods more palatable and tempting to eat

Question 15

How do we extract oils from plants?2

Answer 15

By pressing

Or distillation

Question 16

What is the test and result for unsaturated fats?

Answer 16

Bromine

Turns colourless

Question 17

Describe the reaction and conditions needed to harden a vegetable oil?

Answer 17

Reacts with hydrogen
Using a nickel catalyst
At about 60 degrees

Question 18

What is hydration?

Answer 18

A reaction with water or steam

Question 19

What part of an emulsifier is hydrophilic?

Answer 19

Tail

Question 20

What part of an emulsifier is hydrophobic?

Answer 20

Head

Question 21

What comes first in fractional distillation diesel or Petrol?

Answer 21

Diesel

Question 22

If something has E numbers what is it?

Answer 22

Safe

Question 23

What does unsaturated mean?

Answer 23

A carbon carbon double covalent bond

Question 24

What is an emulsion?

Answer 24

Mixture of liquids that do not dissolve in eachother

Question 25

What is the head of an emulsifier?

Answer 25

HYDROPHYLLIC ATTRACYED TO WATER

Question 26

What is the tail of an emulsifierV

Answer 26

HYDROPHOBIC ATTRACTED TO OIL

Question 27

How do you use distillation in the extraction of vegetable oil?

Answer 27

``` Plants boiled in water Oil and water both evaporate Collected by condensation Water and impurities removed Pure plant oil ```

Question 28

Describe how you can extract vegetable oil by pressing?

Answer 28

Collect seeds using combine harvester Crushed or pressed in a factory Impurities removed Processed to make useful products

Question 29

Advantages of using crops for ethanol?

Answer 29

``` Renewable Less energy needed Waste plant material used Carbon neutral Low risk Low technology ```

Question 30

Advantages of crude oil instead of crops for ethanol?

Answer 30

``` Continuous Fewer steps Conserves Food Pure ```

Question 31

Disadvantages of crude oil instead of crops for ethanol?

Answer 31

``` Running out High energy needed Not carbon neutral High safety risks High technology Risk of major spillage ```

Question 32

Disadvantages of using crops for ethanol?

Answer 32

``` Impure ethanol Batch (slow) process Food shortages Large areas need Destructing of habitat Slow to grow crops Labour intensive ```

Question 33

How does the boiling point of vegetable oils change compared to water?

Answer 33

Higher than water

Question 34

How is the high boiling point of vegetable oils useful?

Answer 34

Be used to cook foods at high temperatures | So quicker cooking

Question 35

Why are vegetable oils hardened?

Answer 35

They have a higher melting point so are solids at room temperature Thus can be used as spreads cakes and pastries

Question 36

HARDENING

Answer 36

60 degrees Nickel catalyst Add hydrogen

Question 37

Why harden something

Answer 37

It becomes solid at room temperature so can be used for spreads

Question 38

Properties of polymers depend on what?

Answer 38

Monomers used | Conditions of reaction