An answer related to Ladios's question.
As it hits the floor the energy of the impact is absorbed by the tissues that make up the banana.
When you drop some objects they will shatter, but fruit tissue is able to absorb some of the impact without shattering, but the harder it falls, the more damage will be done.
If the fruit is cold or very rich in water it will be more sensitive to impacts.
The tissue of the banana is made up of millions of tiny cells; each cell is contained by a cell wall. If you break these cell walls by dropping the banana or by biting into it, everything inside the cells will spill out.
This includes iron-rich chemicals called phenols, enzymes called polyphenol oxidase, and oxygen.
When these mix together they undergo an oxidation reaction. In this reaction the iron reacts with oxygen, the same thing happens if you leave your bike out in the rain for a long time, an oxidation reaction turns it rusty.
The bruise on the banana gets its brown colour from pigments called melanins which are produced by the reaction.
This column was supplied by Newcastle’s Centre for Life.