Plant Oils And Their Uses

Question 1

What are vegetable oils important for and why?

Answer 1

They are important foods and fuels as they provide a lot of energy. They also provide us with nutrients

Question 2

Vegetable oils have a …. Boiling point than water. What does this allow them to be used for?

Answer 2

Higher
So they can be used to cook foods at higher temperature a than by boiling. This produces quicker cooking and different flavours but increases the energy that the food releases when it is eaten.

Question 3

What can oils be used to produce?

Answer 3

Emulsions

Question 4

Does oil dissolve in water?

Answer 4

No

Question 5

What are emulsions?

Answer 5

They are thicker than oil or water and have many uses that depend on their special properties. They provide better texture, coating ability and appearance, e.g. In salad dressings, ice cream, cosmetic tamed paints

Question 6

What do emulsifiers have?

Answer 6

Hydrophilic and hydrophobic properties

Question 7

Who can you test for unsaturated or saturated vegetable oils?

Answer 7

Unsaturated vegetable oils contain double carbon-carbon bonds. These can be detected using bromine water. Bromine water becomes colourless when shaken with an unsaturated vegetable oil, but it stays orange-brown when shaken with a saturated vegetable fat.
Bromine water can also be used to determine the amount of unsaturation of a vegetable oil. The more unsaturated a vegetable oil is, the more bromine water it can decolourise.

Question 8

How do you harden unsaturated vegetable oils and why would you do this?

Answer 8

Unsaturated vegetable oils can be ‘hardened’ in a reaction called hydrogenation.
During hydrogenation, vegetable oils/ unsaturated fats are pasted through a nickel catalyst, where they reacts with hydrogen gas at about 60ºC. The double bonds are converted to single bonds in the reaction. In this way unsaturated fats can be made into saturated fats – they are hardened.

Allows them to have a higher melting point
Be solid at room temperature
Good for commercial uses amazing cakes and pastries

Question 9

Some fruit, seeds and nuts are rich in oils that can be extracted. How can they be extracted?

Answer 9

The plant material is crushed and the oil removed by pressing or in some cases by distillation.
Water and other impurities are removed

Question 10

What is the purpose oh hydrogenation and what is the proces?

Answer 10

Unsaturated to saturated (e.g. oils to margarine)
Add hydrogen
Nicole catalyst
60oC