[ELI5] – Why do fruits develop brown/bruised areas when we hit them?

Question

A bruise can only appear when there is circulation, right?

Then why do fruits and vegetables, especially bananas, develope brown spots/bruises when they get hit, even after they being desolidarized from their tree?

Is there still “circulation” in the fruit? Is it oxidation? Or a form of osmosis?

In: Biology

Answer 1

Well, at the most basic form it is just oxidation. Bruises happen when an enzyme called ‘polyphenoloxidase’ oxidises the phenolic compounds found in fruit tissue. So the phenolic compounds turn into brown spots (or ‘bruises’) because of oxidation. I don’t know if that made sense but enzyme oxides compounds basically. Sorry mine was a bit technical