In this simple but easy experiment you will investigate the effect that oxygen has on the darkening of a fruit.
Things Required:
Apple
Vitamin C tablet
Directions:
Cut the unpeeled apple in half. Crush the vitamin C tablet and sprinkle the powder over the cut surface of one of the halves of the apple. Allow both the sections of the apple to set uncovered for one hour. Observe the colour of each section.
This Is What Happens:
The untreated section turns brown, but the section treated with vitamin C is unchanged.
Science Behind It:
Apples and other fruits, such as pears and bananas, discolour when bruised or peeled and exposed to air. This discolouration is caused by chemicals called enzymes. The enzymes are released by the damaged cells and react with oxygen to digest the cells of the fruits. Rapid colour and taste changes occur because of the reaction with oxygen. Vitamin C prevents the darkening by reacting with the enzyme before it can start digesting the cell tissue.
