Plant Oils Flashcards Preview

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Flashcards in Plant Oils Deck (27)
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1
Q

Some [ ] and [ ] contain a lot of oil

A

Plants and seeds

2
Q

What can plant oil be used for?

A

Food or fuel

3
Q

How can oil be extracted from plants? (Traditional method)

A

1) The plant material is crushed

2) Press the crushed plant material between metal plates and squash the oil out

4
Q

What does distillation do?

A

Refines oil, and removes water, solvents and impurities

5
Q

Apart from crushing, how else can you get oil from plants?

A

Using solvents

6
Q

How is oil separated fro crushed plant material?

A

A centrifuge

7
Q

Why are vegetable oils used in food?

A

1) Provide a lot of energy - high energy content
2) There are other nutrients in vegetable oils
3) vegetable oils contain essential fatty acids, which the body needs for many metabolic processes

8
Q

Why are vegetable oils used in fuel?

A

1) They provide a lot of energy

9
Q

Why is a very useful fuel made from vegetable oils? Describe it.

A

Biodiesel - has similar properties to ordinary diesel - it burns the same way, so you can use it to fuel a diesel engine

10
Q

What do unsaturated oil contain?

A

C=C bonds

11
Q

What type of molecules do oils and fats contain?

A

Long-chain molecules with lots of carbon atoms

12
Q

Oils and fats can either be [ ] or [ ]

A

Saturated or unsaturated

13
Q

What will an unsaturated fat do to bromine water

A

Make the bromine water turn colourless - decolourise it

14
Q

What are monounsaturated fats?

A

Fats that contain ONE C=C double bond somewhere in their carbon chains

15
Q

What are polyunsaturated fats?

A

Fats that contain MORE than one C=C double bond

16
Q

Unsaturated oils can be [ ]

A

Hydrogenated

17
Q

What state are vegetable oils at room temperature?

A

Liquid

18
Q

What is hydrogenation?

A

Vegetable oils can be hardened by reaction them with hydrogen in the presence of a nickel catalyst at about 60 °C.
The hydrogen reacts with the double-bonded carbons ad opens out the double bonds

19
Q

Can you draw the diagram for a hydrogenation reaction of ethene?

A

Answer page 61

20
Q

What differences do hydrogenated oils have from normal oil? Why is that useful?

A

1) Higher melting points - therefore more solid at room temp. This makes them useful as spreads

21
Q

Describe the hydrogenation of margarine

A

Usually made from partially hydrogenated vegetable oil - turning ALL the double bonds to single bonds would make the margarine too hard and difficult to spread

22
Q

Why are partially hydrogenated vegetable oils used instead of butter in processed foods?

A

They are a lot cheaper than butter and they keep a lot longer

23
Q

What is the disadvantage of partially hydrogenated vegetable oils?

A

You end up with a lot of trans fats. There’s evidence to suggest that trans fats are very bad for you.

24
Q

Vegetables oils tend to be [ ], while animals fats tend to be [ ]

A

Vegetable: Unsaturated
Animal: Saturated

25
Q

Which is unhealthier, saturated or unsaturated? Why?

A

Saturated fats (generally) - they increase the amount of cholesterol in the blood, which can block up the arteries and increase the risk of heart disease

26
Q

Describe unsaturated fats in relation to cholesterol

A

Natural unsaturated fats reduce the amount of blood cholesterol. But because of the trans fats, partially hydrogenated vegetable oil increases the amount of cholesterol in the blood

27
Q

What does cooking food in oil make the food?

A

More fattening