> Most of the defense systems of the fruit are in its skin. And a lot of

And Stefan reminded just reminded me of another important point:

With many fruits the taste of the skin is very important for
the instinctive reaction. Oranges, for example: One should
eat oranges only if the skin tastes so good that it can be
removed by using only the teeth. Because our ancestors would
normal have done just that: Smell the fruit, take it in a
hand and bite into it or skin it with the teeth.

And we have found out that the taste of these fruit skins
becomes so attractive that one likes to bite into them when
the body really needs them.

-Karl