Why does the olive tree produce a bitter tasting fruit?

Question

What is the survival value for the olive tree to produce a bitter tasting fruit, even when it is ripened? I realize some fruits and berries are species specific, i.e., meant for specific animals to eat and disperse the seed widely. Is this the case of the olive?

Answer 1

Water soluble polyphenols cause the bitter taste in olive fruits. That is why the separated oil (remember oil and water do not mix) does not taste bitter. The bitter taste however is specific to the taste receptors of animals that eat them. Birds that are involved in olive seed dispersal (the scientific term is "zoochory") do not taste the bitterness (just like chilli peppers do not "taste hot and spicy" to birds) , so seed dispersal by birds is unaffected.