Plant Oils Flashcards
How can the oil be removed from plant matter?
> can be crushed
> oil extracted by being crushed between metal plates
> oil removed using a centrifuge or solvents
> distillation to refine and remove solvents, water and impurities
What are the benefits of using oil in food?
> provides more energy
> provides vitamins
> provides fatty acids
What are the benefits of using vegetable oil in cooking?
> it has a higher boiling point and so cooks food more quickly
> it provides more energy
> it can provide more flavour
- oil provides its own flavour
- most flavours are oil-soluble and so it carries other flavours well
What is meant by a monounsaturated fat?
> at fat with only 1 C–C bond somewhere in its molecule
What is meant by a polyunsaturated fat?
> a far with more than 1 C–C bond somewhere in its molecule
Describe the process of hydrogenation?
> vegetable oils are reacted with H2 at 60 degrees Celsius with a nickel catalyst
> breaks the double C bond as H bonds with the C atoms
How is margarine made and why?
> partially hydrogenated vegetable oil.
- if fully hydrogenated would be too hard
- gives it buttery spreadable texture
Why are partially hydrogenated vegetable oils often used in processed foods?
> they are cheaper than butter and last longer
Why are people against the use of partially hydrogenated vegetable oil?
> because there is evidence that ‘trans fat’ is bad for you
What are 2 consumer benefits of partially hydrogenated vegetable oil?
> it is spreadable
> is is hard enough to be used for baking
What are the health risks of saturated fats?
> especially animals fats, increase amount of cholesterol in the blood,
> can cause a buildup in the arteries, increasing chances of heart disease
What are the risks of partially hydrogenated vegetable oil?
> because it is a trans fat it increases blood cholesterol levels, again increasing risk of heart disease
