Plant Oils

Question 1

What does vegetable oil provide?

Answer 1

Lots of energy and important nutrients

Question 2

What are vegetable oils also used as?

Answer 2

Biofuels such as biodiesel

Question 3

What do vegetable oil molecules have?

Answer 3

Hydrocarbon chains

Question 4

If there are several double bonds in each molecule what are the bonds called?

Answer 4

Polysaturated

Question 5

What are carbon-carbon double bonds called?

Answer 5

Unsaturated

Question 6

What do unsaturated oils react with and what colour does it turn?

Answer 6

Bromine water which goes from orange to colourless if it is unsaturated

Question 7

What are the boiling points of vegetable oils?

Answer 7

Higher bp than water so food is cooked at higher temperatures in oil so it cooks faster

Question 8

What does vegetable oil change about your food?

Answer 8

Flavour and texture

Question 9

Does vegetable oil increase the energy content of your food?

Answer 9

Yes as the food absorbs the food increases

Question 10

What happens when unsaturated oils react with hydrogen?

Answer 10

The double bonds become single, this is called hydrogenation

Question 11

Give some details about the hydrogenation reaction

Answer 11

Done at about 60 degrees and uses a nickel catalyst

Question 12

What do hydrogenated oils have?

Answer 12

Higher melting points as they are more saturated

Question 13

What is hydrogenation also known as?

Answer 13

Hardening as they are solids at room temperature

Question 14

Does oil dissolve in water?

Answer 14

No but they can be used to make emulsions

Question 15

What’s an emulsion?

Answer 15

A mixture of liquids that do not dissolve each other

Question 16

What happens if you shake oil and water?

Answer 16

Tiny droplets form that can be slow to separate

Question 17

How do emulsions of oil and water compare to oil and water?

Answer 17

They are opaque and thicker. This improves texture, appearance and their ability to coat and stick to solids

Question 18

Examples of emulsions

Answer 18

Milk
Ice cream
Salad dressing
Mayo

Question 19

How can you recognise an emulsion?

Answer 19

Opaque and coats solids

Question 20

What are emulsifiers

Answer 20

Substances that help stop the oil and water from separating into layers

Question 21

How do emulsifiers work?

Answer 21

They have a hydrophilic head which is attracted to water and hydrophilic tail which is attracted to oil. The hydrophobic parts go into each oil droplet and so the droplets became surrounded by the hydrophilic parts. This keeps the droplets apart in the water, preventing them from joining together and separating out

Question 22

Why can you not see through an emulsion?

Answer 22

The liquids re,aim as tiny droplets and do not dissolve but in abolition Ruth’s substances dissolve which means they mix completely and the solution is clear

Question 23

Are unsaturated or saturated fats better for you?

Answer 23

Unsaturated

Question 24

What do saturated fats have links to?

Answer 24

Heart disease

Question 25

What is good about emulsions but also bad?

Answer 25

They make foods smoother and creamier but are High in fats so you are tempted to eat more

Question 26

How can vegetable oil be extracted from seeds, nuts and fruits?

Answer 26

Pressing or distillation followed by removing water and other impurities