C1.7 Plant oils

Question 1

two methods of oil extraction

Answer 1

==pressing-crushing plantg material
=water and oil is evaporated
==Distillation involves boiling the plant and condensing the evaporated oils released
and removing water and other impurities

Question 2

Vegetabele oils

Answer 2

They can be saturated or unsaturated.

Unstaurated oils are healthier

Question 3

Hydrogenation

Answer 3

turning unsaturated oils into saturated oils -having a higher melting point so they are solids .
Needs:
=hydrogen
=nickel ctaalyst
=at 60C
• Oils that have been treated this way are called hydrogenated oils. Because they
are solids at room temperature, it means they can be made into spreads (e.g. butter
and margarine for bread, etc)

Question 4

EMULSION

Answer 4

mixture of oil and water

Question 5

Unsaturated oils

Answer 5

All vegetable oils have chains of carbon atoms with hydrogen atoms attached
• Some vegetable oils have carbon=carbon double bonds. These are unsaturated oils

Question 6

why are vegetable oils used for cooking

Answer 6

Vegetable oils are useful in cooking because:
- they have a high boiling point, and so foods can be cooked in them at very high
temperatures
- they allow food to absorb the oils, increasing their energy content

Question 7

E-numberas

Answer 7

We use food additives to improve the features of our foods

• Approved European food additives are allocated E-numbers

Question 8

How can we detect unknown food additives

Answer 8

• We can detect unknown food additives using chromatography, by comparing their
chromatograms against those of substances we already know
• We can also use a mass spectrometer