C1.6 - Plant Oils And Their Uses Flashcards
How is oil obtained from plants? (2)
- The plant is crushed.
2. The crushed material is pressed between metal plates to squeeze the oil out.
What can be used to get oil from plant materials? (2)
Solvents or a centrifuge.
What does distillation to to oil? (2)
- Refines it.
2. Removes water, solvents and impurities.
What are the benefits of cooking with vegetable oils? (3)
- Higher boiling points than water - can cook food faster at higher temperatures.
- Gives a different flavour.
- Increases the energy that we get from the food.
What will an unsaturated oil do to bromine water?
Decolourise the bromine water.
What is the difference between monounsaturated fats and polyunsaturated fats?
Monounsaturated fats contain one double C=C bound, whereas polyunsaturated fats contain more than one double C=C bond.
What are the necessary conditions for hydrogenation?
A nickel catalyst at about 60 degrees.
What is the difference in an oil once it has been hydrogenated?
It has a higher melting point and is more solid at room temperature.
What to animal fats do to blood cholesterol?
Increase it.
What do natural unsaturated fats do to blood cholesterol?
Decrease it.
What to partially hydrogenated vegetable oils do to blood cholesterol?
Increase it.
What are you at risk of if you eat foods high in animal fats/partially hydrogenated vegetable oil?
Heart disease.
What are the advantages of using vegetable oils in foods? (3)
- They provide lots of energy.
- They contain nutrients.
- They contain essential fatty acids.
What are the advantages of using emulsifiers? (2)
- They give food a longer shelf life because they prevent the ingredients from separating.
- They allow food companies to make food lower in fat that still has a good texture.
What is the disadvantage of using emulsifiers?
Some people are allergic to them e.g. egg yolk.
