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Flashcards in Revision Guide - Plant Oils Deck (23):
1

What bonds do unsaturated oils contain?

C=C double bonds

2

What sort of molecules do oils and fats contain?

Long-chain molecules with lots of carbon atoms

3

Are oils and fats saturated or unsaturated?

They can be either

4

What bonds do unsaturated oils contain?

Double bonds between some of the carbon atoms in their chains

5

What will unsaturated oils do to bromine water?

decolourise it

6

What bonds to monounsaturated oils contain?

ONE C=C double bond somewhere in their carbon chains

7

What bonds to polyunsaturated oils contain?

More than one C=C double bond 

8

How can unsaturated oils be hardered? How does this work?

By hydrogenation

Reacting them with hydrogen over a nickel catalyst at about 60 degreesC

→ The hydrogen reacts with the double-bonded carbons and opens out the double bonds

9

How are hydrogenated oils useful? why?

They can be useful as spreads for baking 

→ Because they have higher melting points than unsaturated oils so they're more solid at room temperature

10

What is used instead of butter in processed foods? Why?

Partially hydrogenated vegeatable oils 

→They're a lot cheaper than butter and they keep longer

Makes the food cheaper and have a long shelf life

11

What do partially hydrogenated vegetable oils contain?

Trans fats - which can be very bad for you?

12

Whats healthier: saturated or unsaturated fats? Why?

Saturated fats are less healthy, as they incease the amount of cholesterol in the blood, which can block up the arteries and increase the risk of heart disease

13

What can reduce the amount of blood cholesterol?

Natural unsaturated fats

14

What can increase the amount of blood cholesterol?

Saturated fats 

And partially hydrogenated vegetable oil

15

What does cooking food in oil do? heath wise

Makes it more fattening

16

What are emulsions made of?

Lots of droplets of one liquid suspended in another liquid

17

The more oil you have in an oil-in-water emulsion..

The thicker it is

18

Some oil-in-water emulsions?

Milk

Whipped cream

Ice cream

19

Non-food emulsion uses?

Body lotions - the smooth textures make it easy to rub into the skin

20

What are emulsifiers?

Molecules with one part thats attracted ti warer and another part thats attracted to oil or fat

21

In an emulsifier; what is the part thats attarcted to water called?

Hydrophilic

22

In an emulsifier; what is the part that is attracted to oil called?

Hyrophobic

23

Pro's and cons of emusifiers?

 ✓ They stop emulsions from sepearating out 

 ✓ Gives them a long shelf life

 ✓ Allow food companies to produce food thats lower in fat but still have a food texture

 

✗ Some people are allergic to certain emulsifiers