Core Chemistry AQA Section 6

Extracting Vegetable Oil

-Some seeds nuts and fruit are rich in vegetabe oils which can be extracted by crushing and pressing the plant material followed by removing water and other impurities, some ois are extracted by distilling the plant material mixe d with water which produces a mixture of oil and water from which the oil can be separated.

-When eaten veg oils privude us with lots of energy and importanr nutrients, vegetabe oils release a ot of energy when the burn in air and so can be used as fuels and are used to make biofuels e.g biodiesel.

-The molecules in veg oils have hydrocarbon chains, those with carbon-carbon double bonds are unsaturated, if they gace several double bonds in each moecule they are caled polyunsatyrated. unsaturated oils react with bromine water turning it from orange to colourless. 

Cooking with Veg Oils

-The boiling points of veg oils are higher than water so food is cooked at high temperatures in oil meaning they cook faster. The colour, flavour and texture is changed as well. Some oil is absorbed so the energy content in the food increases.

-Unsaturated oils can be reacted with hydrogen so that ome or all carboin double bonds become single bonds. The reaction is hydrogenation and done at about…