Rubbing eggplants in salt
I've heard that salting an eggplant (aubergine) before cooking/frying it is necessary not only to reduce the amount of liquid in the result but also to rid the eggplant of some bitterness. I see, online, some support for the claim that the taste of salt removes bitterness, but that would not require pre-salting: one could simply add salt to the dish. And that same Web page also says eggplants on the market generally lack bitterness anyway. On the other hand, various other Web pages (example) matter-of-factly describe pre-salting eggplants to rid them of bitterness. So my questions are: Is it true pre-salting reduces bitterness to an extent that regular salting of a dish does not, and, if so, are eggplants on the market (in the States, say) bitter enough to make bitterness-reduction advisable?