Extracting vegetable oil
Vegetable oils can be extracted from seeds, nuts and fruits by pressing or by distillation.
Vegetable oils provide nutrients and a lot of energy. They are important foods and can be used to make biofuels.
Unsaturated oils contain carbon-carbon double bonds, so they decolourise bromine water.
Cooking with vegetable oils
Vegetable oils are useful in cooking because of their high boiling points.
Cooking in oil increases the energy content of foods and changes the flavour, colour and texture of the food.
Vegetable oils can be hardened by reacting them with hydrogen at 60 degrees with a nickel catalyst. This makes them solids at room temperature that are suitable for spreading.
Oils do not dissolve in water but oils and water can be used to produce emulsions. These have special properties.
Emulsions made from vegetable oils are used in many foods.
Emulsifiers stop oil and water from separating into layers.
Emulsifiers have molecules in which one part is hydrophobic (water hating tail) and one part is hydrophillic (water loving head).
Vegetable oils are high in energy and provide nutrients.
Vegetable oils are believed to be better for health than saturated fats.
Emulsifiers improve the texture of foods enabling water and oil to mix. This makes fatty foods more palatable and tempting to eat.