Emulsions Flashcards
Where can you find emulsions happening?
Foods.
Paints.
Cosmetics.
What can emulsions be made from?
Oil and Water.
Oils don’s dissolve in where?
In water.
You can mix oil and water to make what?
An emulsion.
What are emulsions made up of?
Lots of droplets of one liquid suspended in another liquid.
Give an example of an emulsion?
Oil-in-water emulsion.
Oil droplets suspended in water.
Water-in-oil emulsion.
Water droplets suspended in oil.
Emulsions are thicker than what?
Oil and water.
What is mayonnaise an emulsion of?
Sunflower oil and vinegar.
Its thicker than either.
The physical properties of an emulsion make them suited for what?
Uses in food.
Eg salad dressing and in sauces.
Give an example of a food emulsion?
A salad dressing is made by shaking olive oil and vinegar together, it coats salad better than plain oil and plain vinegar.
The more oil you’ve got in an oil-in-water emulsion what is the emulsion going to be like?
Thicker.
Give an example of an oil-in-water emulsion?
Milk.
Its got not much oil but a lot of water.
About 3% of oil in full-fat milk.
How much oil is there in creams?
Single cream has 18% oil.
Double cream has nearly 50%.
Whipped cream and ice cream are examples of what emulsion?
Oil-in-water with an extra ingredient air.
What does air do in whipped cream?
Makes it fluffy.
Frothy consistency for use as a topping.
What does whipping air into ice creams do?
Gives it a softer texture.
Making it easier ti scoop out the tub.
Name a non-food emulsion.
Moisturising lotions are oil-in-water emulsions.
The smooth texture of an emulsion makes it easy to rub into the skin.
What are emulsifiers?
Molecules with one part attracted to water and another part attracted to oil or fat.
The bit that is attracted to water is called hydrophilic.
The bit that is attracted to oil is called hydrophobic.
What does the hydrophilic end of each emulsifier do?
Latches onto water molecules.
What does the hydrophobic end of each emulsifier do?
Cosies up to the oil molecules.
What happens when you shake oil and water with a bit of emulsifier.
The oils forms droplets surrounded by a coating of emulsifier with the hydrophilic bit facing outwards.
Other oil droplets are repelled by the hydrophilic bit of the emulsifier, while water molecules latch on.
So the emulsion won’t separate out.
Give 2 pros about emulsifiers.
Stop emulsions separating out giving them a longer shelf life.
Allows food companies to produce food that’s lower in fat but still has a good texture.
Name a con about emulsifiers.
People are allergic to emulsifiers.
Eg egg yolk is often used as an emulsifier so people allergic to eggs needs to check ingredients carefully.
