Certainly, if I were making a salad with canned beans, I would thoroughly rinse them first. But if I'm making soup or chili with canned black beans or kidney beans, should I drain and rinse them first? Goya brand beans have recipes on the side of the can that call for undrained beans.
On the one hand, I've heard claims that using the liquid in the can will increase gassiness, and that in some brands it can contain a lot of sodium. But I've also heard that it contains lots of soluble fiber that is lost if drained. Is there merit to either of these claims? Are there other nutrients that get lost if I drain and rinse? I always feel bad throwing out anything edible.