C1.6 Plant Oils

Question 1

What’s oil used for?

Answer 1

Cooking
Cars
Cosmetics like soap and perfume
Biodiesel

Question 2

What’s pressing?

Answer 2

Fruits, seeds or nuts are crushed and pressed to extract the oil and then you remove the impurities
Eg. Sunflower and olive oil

Question 3

What’s distillation?

Answer 3

Plant seeds are crushed and it is mixed with water. Oil is placed in distillation flask and oil mixture is heated. The steam goes through the plant and the oil evaporates. Oil (and water) is collected by condensing it eg. lavender oil. Oil floats to the top - impurities are removed.

Question 4

Are saturated or unsaturated things more healthy?

Answer 4

Unsaturated are healthier

Have less energy

Question 5

Butters and oils, which ones are saturated and unsaturated?

Answer 5

Hard oils like butter and lard are saturated

Oils like vegetable oil are unsaturated

Question 6

What are properties of vegetable oils?

Answer 6

High boiling points
Quite viscous
Contains lots of stored ‘chemical energy’

Question 7

What are uses of vegetable oils?

Answer 7

Food ingredients
Fuel like biodiesel
Emulsifiers

Question 8

What are the two ways of extracting oil?

Answer 8

Pressing

Distillation

Question 9

What are the advantages of cooking with vegetable oil?

Answer 9

High boiling point
Cook at higher temperatures than by boiling
Cook faster
Different flavours
Food has higher energy storage

Question 10

What are the similarities and differences between fats and oils?

Answer 10

Both lipids
Fats are solids are room temp but oils are liquids
Fats are more saturated
Fats are generally an animal product where as oils are often a plant derived product

Question 11

What’s hydrogenation?

Answer 11

When you take unsaturated oils an turn them into saturated oils. This is done by adding hydrogen to the unsaturated oil. The temperature is 60 degrees c and in presence of a nickel catalyst.

Question 12

What’s the process of turning unsaturated oils into saturated fats?

Answer 12

Hydrogenation

Question 13

What are immiscible liquids?

Answer 13

They don’t mix together

Eg. Oil and water

Question 14

What are emulsions?

Answer 14

Substances that mix together in the presence of an emulsifier.
Eg. Paint and mayonnaise

Question 15

What’s an emulsifier?

Answer 15

Mixes together two immiscible substances. The substance made is an emulsion.

Question 16

What are the features of an emulsifier to bond oil and water?

Answer 16

They have a hydrophilic head which is attracted to water and a hydrophobic tail which is attracted to oil.
The tails dissolve in oil making tiny droplets. The surface of each oil droplet is charged by the heads sticking out into the water. As like charges repel, the oil droplets repel each other and this keeps them spread throughout the water, stopping the oil and water separating.

Question 17

Give some examples of emulsions.

Answer 17

Mayonnaise
Butter
Milk
Paint

Question 18

Why are emulsions useful?

Answer 18

Have different textures, tastes and coating properties

Question 19

What are additives?

Answer 19

They’re in processed foods to improve appearance, taste and shelf-life. And also stops ingredients separating- emulsifiers

Question 20

Food additives can be….

Answer 20

Emulsifiers
Flavour enhancers
Antioxidants
Food colours

Question 21

What are antioxidants?

Answer 21

An additive that improves shelf life because they stop reactions with oxygen.

Question 22

What are E numbers?

Answer 22

Represent additives

Question 23

How are unsaturated fats in vegetable oils good for you?

Answer 23

Include vitamin E so clear arteries and reduce heart disease and have lower cholesterol
But they cause obesity