I actually just asked my mother-in-law about putting fruit into my composter
(I'm new to all of this as well).
Her motto was always that if it oxidized, it wasn't any good. Obviously, citrus fruit won't do that, but the excess sugars could have an adverse effect on it. As mentioned, I'm going by my mother in law's word.
Also, I'm not sure where you're from, but I'm from a very large city.
I managed to find this composting site specifically for NYers and it's certainly helped me. Maybe it'll help you too:http://www.nyccompost.org/