Fats & oils Flashcards
Why are edible fats important
•they provide a concentrated source of energy
•they are essential for the transport and storage of fat soluble vitamins in the body
What are edible fats and oils
Naturally occurring compounds
How can edible fats be achieved
• Animals sources- beef fat, lard
•vegetable sources- olive oil, sunflower oil, rapeseed oil
•marine sources- cod liver oil, Sardis oil, whale oil
Glycerol
Alcohol known as a triol as it contains 3 hydroxyl group
The long chained Carboxylic acids in edible fats and oils are know as
Fatty acids
Number of carbons atoms in the chain ranges to 4-20 these acids can be saturated or unsaturated
What do the fatty acids contain
Only carbon to carbon single bond and the unsaturated fatty acids contain at least one carbon to carbon double bond
Esters, fats and oils made in
Condensation
As glycerol molecules contain three hydroxide groups that will condense with
Fatty acid molecules to form the ester present in oils
What is an ester called that from glycerol
Glyceride
What are esters that are present fats and oils called
Triglycerides
Main difference between fats and oils
Fats are solid at room temperatures and oils are liquid
How can the main difference be looked at when it comes to melting points of ate and oils
By looking at the structures of fat and oil molecules and the strength of their IMF
the melting and boiling points of fats and oils is directly proportional to the number of what
Carbon to carbon double bonds
The more carbon to carbon double bond a fat or oil has the
Lower the melting point
Fats are made from mostly what
Saturated fatty acids
What does the shape of fatty acids allow molecules to do
Pack closely together and allow the formation of stronger IMF between molecules
What do the strong IMF result in
Fats being solid
Oils contain more what?
Unsaturated fatty acids and fats
What does the carbon carbon double bond cause?
A kink in the chain preventing the molecule from packing closely together
The greater the number of carbon carbon double bonds the
Weaker the Vanderwell forces resulting lower melting points
Due to their shape molecules tend to
Less compact than fat molecules which implies that their LDF are weaker than that of fat molecules
The weaker the LDF are
The less energy will be needed to break them resulting in oils having lower melting points and fats
Close packing in molecules allows what
More cross linking between the chains and comparison oil
What does more cross linking result in
Stronger intermolecular forces and higher melting points
The melting point of oil can be increased by reacting them with what?
Hydrogen in the presence of nickel catalyst
During this process, hydrogen molecules add what?
Some of the carbon carbon double bonds
What is this process known as?
Hydrogenation
What is the effect of this process
The degree of unsaturation in the oil is reduced which increases the melting point
Ie
Unsaturated liquid oil is turned into a solid
Chemical test that determines if a fat or oil is saturated
Add bromine water and if the molecules is unsaturated then the bromine water will de colourise
Oil does what to bromine
Decolourises, to a greater extent that fats due to their high degree of unsaturation
The more carbon to carbon double bonds an oil has the greater?
The volume of bromine solution that can be decoloursied
Fats and oils tend to be used as what
Long term energy sources
What about carbohydrates
Immediate sources of energy
What do fats and oils provide the body with
Essential fatty acids such as linoleic and linoec acid
Why is that important
For blood coagulation and brain development
Why are fats and oils necessary for as well for the body
Transport fat soluble vitamins around the body
Birman A & D are only soluble in fats due to them being non polar molecules like fats and acids
Lack of fats and oils in a DDIT do what
Results in Birman deficiencies
