Properties of Lipids - Emulsions

Question 1

What is an emulsion?

Answer 1

When two immiscible liquid are forced together

Question 2

What are the two different types of emulsions?

Answer 2

Temporary emulsions

Permanent emulsions

Question 3

What are emulsions normally composed of?

Answer 3

Oil in water

Water in oil

Question 4

Give an example of an oil in water emulsion

Answer 4

Milk

Question 5

Give an example of a water in oil emulsion

Answer 5

Butter

Question 6

What is a permanent emulsion?

Answer 6

An emulsion made when oil and water are forced together permanently in the presence of an emulsifier

Question 7

Give an example of a permanent emulsion

Answer 7

Mayonnaise = oil and vinegar + emulsifier

Question 8

What emulsifier is used in mayonnaise?

Answer 8

Lecithin from egg yolks

Question 9

What is a temporary emulsion?

2

Answer 9

An emulsion made when oil and water are forced together by shaking
This emulsion is temporary and will therefore separate when left standing

Question 10

Give an example of a temporary emulsion

Answer 10

French dressing = oil and water + shaking motion

Question 11

How does an emulsifier join an oil and a water together?

3

Answer 11

An emulsifier has a hydrophilic head and a hydrophobic tail
The hydrophilic head attaches to the water or vinegar while the hydrophobic tail attaches to the oil
This prevents the oil and water/vinegar from separating