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Flashcards in Plant Oils Deck (37):

Define 'plant oil'

Oil extracted from a plant


Some fruits and seeds contain a lot of ____

Some fruits and seeds contain a lot of oil


Give 2 examples of fruits that contain a lot of oil

1. Avocados

2. Olives


Give 2 examples of seeds that contain a lot of oil

1. Sesame

2. Peanuts


What two things can plant oils be used for

1. Food

2. Fuel


What are the 2 steps to getting the oil out of the plant material (but not seperating)

1. Crushing the plant material

2. Press the crushed plant material between two metal plates and squash the oil out



Name the 2 ways oil can be separated from the crushed plant material

1. By using a centrifuge

2. By using solvents


What is teh next step after separating oil from crushed plant material, and what does it do?


Refines oil, and removes:

1. Water

2. Solvents

3. Impurities


Name 3 advantages of using vegetable oil in food

1. Provide a lot of energy as have a high energy content

2. Other nutrients in vegetable oils

3. Contain fatty acids; needed for many metabolic processes


What kind of nutrient do seed oils contain?

Vitamin E


Name 3 benefits of using vegetable oils in cooking

1. Higher boiling points than water - can cook food at higher temp.s and faster* speeds

2. Gives food a different flavour

3. Using oil to cook food increases the energy we get from eating it


(on exam you have to put cooks faster as result of higher boilng point than water to get the mark)


Why do oils give foods a different flavour?

1. Oil gives its own flavour

2. Many flavours come from chemicals that are soluble in oil - the oil 'carries' the flavour, making it more intense


Name 2 types of oil that can be processed and turned into fuels

1. Rapeseed

2. Soybean


What makes vegetable oils so suitable for use as fuels?

They contain a lot of energy


Name a particularly useful type of fuel made from vegetable oil



What makes biodiesel such a useful fuel?

It has similar properties to ordinary diesel - burns in the same way, so can use it to fuel a diesel engine (no modifications necessary)


Why do we need to hydrogenate oils to use them as spreads?

They are usually liquids at room temperature


Unsaturated oils contain which kind of carbon bond?

Double bonds between some of the carbon atoms in their carbon chains


What do oils and fats contain?

Long-chain molecules with lots of carbon atoms


Oils and fats are either ____ or ____

Oils and fats are either saturated or unsaturated


What will unsaturated oil do to bromine water, and why?

Decolourise it from orange to colourless, because the bromine opens up the double bond and joins on


How many carbon double bonds do monounsaturated fats contain?


Somewhere in their carbon chains


How many carbon double bonds do polyunsaturated fats contain?

More than one

In their carbon chains


What state are unsaturated vegetable fats at room temperature?



How do you harden/ hydrogenate unsaturated vegetable oils?

By reacting them with hydrogen in the presence of a nickle catalyst at a temp of 60oC


What happens during hydrogenation?

The hydrogen reacts with the double-bonded carbons and opens out the double bonds


Hydrogenated oils have ____ ____ ____ than unsaturated oils, making them ____ ____ at room temperature.

Hydrogenated oils have higher melting points than unsaturated oils, making them more solid at room temperature


How does being more solid at room temperature make hydrogenated oils more useful than unsaturated ones with baking?

Hydrogenated oils are useful as spreads for baking cakes and pastries


Margarine is usually made from ____ hydrogenated vegetable oil.


Margarine is usually made from partially hydrogenated vegetable oil.

Turning all the double bonds to single bonds would make maragarine too hard and difficult to spread. Hydrogenating most of them gives margarine a nice, buttery, spreadable consistency.


In what kind of food are partially hydrogenated vegetable oils usually used in instead of butter?

Processed foods


For what 2 reasons are partially hydrogenated vegetable oils used in processed foods instead of butter?

1. They are cheaper - makes biscuits cheaper

2. They keep longer - gives them a longer shelf life


Name a disadvantage of eating partially hydrogenateed vegetable oils

They contain a lot of 'trans fats'

Evidence to suggest that trans fats are very bad for you


Vegetable oils tend to be ____, while animal fats tend to be ____

Vegetable oils tend to be unsaturated, while animal fats tend to be saturated


Why are saturated fats generally less healthy than unsaturated fats?

Saturated fats increase the amount of cholesterol in the blood, which can block up the arteries and increase the risk of heart disease


Name an advantage of natural unsaturated fats such as olive oil and sunflower oil

They reduce the amount of blood cholesterol


Explain why partially hydrogenated vegetable oils are worse for you than the natural ones

Partially hydrogenated vegetable oils contain trans fats which increase the amount of cholesterol in the blood, increasing the risk of heart disease


Name a disadvantage to cooking food in any sort of vegetable oil

It makes the food more fattening