1. Oils from plants C1.6

2. What do I need to know? Recall that oils can be obtained from plants Describe the properties of oils and formation of emulsions Explain why saturated fats are solid and unsaturated fats are liquids

3. Vegetable oils Oils can be extracted from fruits, seeds, flowers and nuts. The plant material is crushed and the oil removed by pressing or steam distillation. Water and other impurities are then removed.

6. Vegetable oils Vegetable oils are important fuels and foods and they provide us with energy and nutrients.

7. Cooking with vegetable oil Vegetable oils have higher boiling points than water. This means they can be used to cook food more quickly than boiling. This also increases the energy the food releases when it is eaten.

9. Emulsions Oils do not dissolve in water. This is because they FLOAT Oils can be used to make emulsions – these are thicker than water and have useful properties.

11. What do we use emulsions for? Emulsions are good for coating surfaces eg paint and cosmetics. They have an appealing texture in food eg ice cream and mayonnaise

12. Oil and water? What will happen to a mixture of oil and water over time? It will separate

13. Emulsifiers Emulsifiers keep the product in an emulsion and stop it separating out Emulsifiers are molecules that have one part that is attracted to water and one that is attracted to oil. An example is washing up liquid.

14. Emulsifiers Emulsifiers have a head that is attracted to water and a tail that is attracted to the oil.

17. Unsaturated oils Unsaturated fats like olive oil have double bonds and decolorize bromine water. When making margarine hydrogen is passed through the oil in the presence of a nickel catalyst at 60°C This fills up the molecule with hydrogen making it a solid fat.