Plant Oils Flashcards
How can vegetable oils be extracted from seeds?
By crushing and pressing the plant material followed by removing water and other impurities
What are some seeds, nuts and fruits rich in?
Vegetable oils
How are some oils extracted other then by crushing
By distil long the plant material mixed with water - this produced the mixture of oil and water from which the oil can be separated
What’s distillation?
Deprecation of a liquid from a mixture by evaporation followed by condensation
What do vegetable oils provide & what can they be used to make?
Nutrients and a lot of energy - they are important foods and can be used to make biofuels
What do unsaturated oils contain and why?
Contain carbon double Bonds so they can decolourise bromine water
Why can vegetable oils be used as fuels?
Because they release a lot of energy when they burn in the air - used to make biofuels such as biodiesel
Molecules in vegetable oils have what?
Hydrocarbon chains
What is it called if there are several double bonds in each molecule?
They care called polyunsaturated
The boiling points of vegetable oils is higher then what, so this means
Food is cooked at higher temps in oil - this means it cooks faster
What does vegetable oil change in foods?
The flavour, colour and texture of foods - some of the oil is absorbed by the food so the energy content of food increases
What can unsaturated oils be reacted with, what does this do? What is this called and what temp and what catalyst is it done with
Can be reacted with hydrogen so that some or all carbon double bonds become single bonds. Hydrogenation and is done at 60 C using a nickel catalyst
The properties of hydrogenated oils - what can they be used to make
Higher melting points because there more saturated and are solids at room temp this mean they can be used as spreads and cakes (hardening)
What’s emulsion?
Mixture of liquids that do not mix with each other
What do emulsions look like?
Opaque, can’t see through, thick coats solid (milk, cream, salad dressings)
