According to TV last night, in order to have a strong body which doesn't catch a cold easily, it is important to have lots of saliva in our mouth. I went to a convenience store to buy dried ume (japanese plum) . It was sweet and salty, but strange taste. I think it contains an artificial preservatives. Taking lots of salt isn't good either. Apparently, it is effective enough just looking at the photograph of a pickled ume and get lots of saliva, without eating something sour. But pickled ume doesn't make C' mouth watery. Not enough 'ume' experience yet.