Task Think of some different types of ‘oil’ used for cooking. What is meant by ‘poly-unsaturated’?

Objectives To know how oils are made. To be able to describe what is meant by an emulsion. C1b – Emulsions Key Words Saturated Hydrogenated Emulsion

There are many types of vegetable oil Sunflower oil Olive oil Palm oil Peanut oil Soybean oil Coconut oil Rapeseed oil

There are 2 ways of extracting the oil from plants One; pressing – seeds are firstly crushed  pressed to extract the oil e.g. sunflower oil

There are 2 ways of extracting the oil from plants Two; using distillation – Plants/seeds crushed -Mixture mixed with water -Oil floats to top (impurities removed) -Oil placed in distillation flask -Oil mixture is heated -Oil evaporates -Oil is collected by condensing it. e.g. lavender oil

A) 3 B) 2 C) 4 D) 1

What the difference? Which is more healthier? Why? Butter Sunflower Oil Saturated FatUnsaturated Fat Heathier – poly is the best How do we test for unsaturation?

Saturated v Unsaturated No free bondsDouble bond – means it is reactive. Double bond can open and bromine can attach. Result - colourless solution

Saturated (NO double bond) Unsaturated (Double bond) Sunflower oil lard butter alkene alkane monomers polymers ethene Poly(ethene)

Imagine cooking a potato chip in water and then in oil. What would be the differences be in terms of the following a) Taste b)texture c) appearance d) smell Why do we cook with oil? Vegetable oil has a much higher boiling point compared to water as the forces between the molecules (intermolecular) are greater. This means the food cooks a lot quicker and gets hotter affecting the taste!

Key point; vegetable oils are unsaturated and liquid at room temperature. They can be hardened with hydrogen in the presence of a nickel catalyst at 60°C – this is called hydrogenation Unsaturated vegetable oil 60ºC Nickel Saturated, hydrogenated Hardened oil Used for fryingUseful as spreads The process of oil to spread – the Hardening Process

Which process is happening here? a)Catalysis b)Hardening c)Unsaturation d)polymerisation

Look at your tube of water and oil and answer the following questions Q1. Draw in pencil a diagram of the tube labelling clearly the water and oil layers Q2. Describe in your own words what you can see Q3 Can you think of a reason for this Q4 predict what would happen if you shake the tube Q5 Think about removing fat/grease from plates with just water – would that work? Do we need to add anything? What do you think that does?

Mixture (shaken for 2 minutes and left to stand) Time taken for the mixture to separate/minutes Oil (5ml) and vinegar (5ml) only in a boiling tube. Oil (5ml) and vinegar (5ml) with a spatula measure of mustard powder in a boiling tube. Experiment 1: Write your results in this table.

1 Put 5cm 3 of vinegar in a boiling tube and then add 5cm 3 of vegetable oil 2 Fit a bung to the boiling tube and shake for two minutes. 3After the 2 minutes of shaking, leave it to stand and time how long it takes for the two layers to separate. Record the time taken in the table. 4Add 5cm 3 of vinegar and a small spatula measure of mustard powder to a clean boiling tube. 5Make sure that a bung is fitted. Shake the mixture to dissolve the mustard powder. 6 Slowly add 5cm 3 of vegetable oil a little at a time, shaking in between additions. 7Shake the mixture for 2 minutes with the bung firmly on. 8Leave the mixture to stand and time how long it takes for the mixture to separate. Record your results in the table

Questions 1Does adding mustard powder make any difference to the separation time? 2What are the functions of mustard powder in the oil and vinegar dressing? 3Why do cooks not add too much mustard to their salad dressing? e.g. Yes, the speed of separation takes longer. e.g. its acts as an emulsifier helping the oil mix and not separate e.g. Adding the mustard to an acid oil mixture will result in the clumping of the mustard.

Oil and water are immiscible (they do not mix). To make them mix we need an emulsifier. The subsequent produce is called an emulsion. Emulsions in every day life are; Milk Mayonnaise Ice cream Salad cream Salad dressing. Emulsifiers keep the oil and water together. Without one you would see blobs of fat floating around!

Distillation Alkane Ethene Alkene Ethane Monomer Cracking Emulsion Catalyst Hydrocarbon Saturated Lard Olive Oil Unsaturated Polymer

An emulsifier has a head that is attracted to water And a tail which is attracted to oil This means it holds together the oil and fat evenly throughout Examples of emulsifiers are soap/detergent Egg yolk e.g. in mayonnaise Explain how emulsifier molecules do their job

Objectives To know how oils are made. To be able to describe what is meant by an emulsion. C1b – Emulsions – Review Time Key Words Saturated Hydrogenated Emulsion