Plant Oils Flashcards
At room temperature what are oils like?
Quite runny.
What can you do to oil to make it into margarine?
Hydrogenate the oil.
What do UNSATURATED oils contain?
Double bonds between some of the carbon atoms in their carbon chains.
Oils and fats contain what?
Long-chain molecules with lots of carbon atoms.
Oils and fats can either be what?
Saturated or unsaturated.
What will a unsaturated oil do to bromine water?
Decolourise it.
As the bromine water opens up the double bond joins on.
What do MONOUNSATURATED fats contain?
One C=C double bond somewhere in their carbon chains.
What do POLYUNSATURATED fats contain?
More than one C=C double bond.
How can unsaturated oils be hardened?
By reacting them with hydrogen in the presence of a nickel catalyst at about 60’C.
By reacting UNSATURATED oil with hydrogen in the presence of a nickel catalyst at about 60’C, what is this process called?
Hydrogenation.
In hydrogenation what does the hydrogen do?
It reacts with the double-bonded carbons and opens up the double bonds.
Hydrogenated oil have a higher what compared to unsaturated oils?
Higher melting point.
More solid at room temperature.
Useful for spreads/baking cakes/pastries.
What is margarine made from?
Partially hydrogenated vegetable oil.
Turning all the double bonds in vegetable oil to single bonds would make the margarine too hard and difficult to spread.
Hydrogenating most of the vegetable oils makes what?
Margarine with a nice, buttery, spreadable consistency.
How is partially hydrogenating vegetable oil better than butter?
They are a lot cheaper and they keep longer.
eg makes biscuits cheaper and gives them a longer shelf life.
Give a negative about hydrogenating vegetable oils?
You end up with a lot of so called trans fats.
Evidence to suggest these trans fats are very bad for you.
Vegetable oils tend to be what?
Animals fats tend to be what?
Veg oil - Unsaturated.
Ani fat - Saturated.
What is healthier saturated fats or unsaturated fats?
Unsaturated fats.
Why are saturated fats bad for you?
Increase the amount of cholesterol in the blood.
Which can block up arteries and increase risk of heat disease.
What do natural unsaturated fats do?
Reduce the amount of blood cholesterol.
Give examples of natural unsaturated fats?
Olive oil.
Sunflower oil.
Because of trans fats partially hydrogenated vegetable oil does what?
Increases the amount of cholesterol in the blood.
Increase risk of heart disease.
Cooking food in oil makes the food more what?
Fattening.
