Fats and Oils Flashcards
main use of fats and oils
- concentrated source of energy
- are essential for the transport and storage of fat-soluble vitamins in the body. non-polar structure allows them to dissolve essential vitamins such as A and D.
other uses of fats and oils
- edible oils used as fuels such as bio-diesel (more important as fuels from crude oil become scarcer/more expensive)
- lubricants for some agricultural machinery made from veg oil to prevent risk of harmful mineral oils contaminating future food stuffs.
structure of fats/oils
- 1x glycerol backbone (alcohol)
- 3x fatty acids (carboxylic acids)
- 3x ester linkages
what is glycerol also known as?
propan-1,2,3-triol
what homologous series do fats and oils belong to?
esters
in what reaction are fats and oils made?
esterification/condensation reaction
what can a fat or oil also be referred to as?
triglyceride
state of fats and oils at room temp
fats are solid
oils are liquids
what determines if the triglyceride is a fat or oil?
the structure of the fatty acid chain
where do fats tend to come from?
animals
where do oils tend to come from?
fish and plants
are fats and oils unsaturated or saturated?
fats are saturated
oils are saturated
do fats or oils have a higher mp
fats have higher mp
oils have lower mp
in other words, what is degree of unsaturation?
how many c=c are present
monounsaturated
one c=c
polyunsaturated
more than 1 c=c
testing degree of unsaturation
more unsaturated the fatty acid, the more bromine it can react with. (more C=C for Br-Br to add on to)
end point of titration colourless–>yellow when no more Br2 can add on as the fatty acid has become fully saturated.
iodine number
mass of iodine in grams that will react with 100g of oil
using iodine to test degree of unsaturation
the iodine reacts with the c=c bonds, so the greater the iodine number, the greater the number of double bonds.
determining degree of unsaturation using formula
it is saturated if it fits the general formula CnH2n+1
if it is not saturated there is 1 double bond for each pair of hydrogen’s lost.
x2+1
process used to convert oils into fats
hydrogenation
what happens to an oil when it is ‘hardened’?
hydrogen is added on to the c=c in the oil which reduces the degree of unsaturation which increases the melting point.
what catalyst is used in hardening of oils
nickel Ni catalyst
example of hardening of oils in real life
production of margarine
edible fats and oils are esters formed from the…
condensation reaction of glycerol with three fatty acid molecules
how many ester links can glycerol form with fatty acid molecules?
3
the greater the number of drops (longer titration)…
more unsaturated the oil.
end point of titration of fats/oils against bromine
when all double bonds have been used up
trace of bromine remains (no further decolouration)
