A friend of ours got us a small package of umeboshi as a present. These are small, pickled Japanese plums, apparently from a very exclusive type of plum tree. They are very cute, and our friend said they are very expensive.
We tried one and have to say it was nearly inedible -- very, very salty, like eating pure salt. No other flavor is discernible. The label says that each 8 gram plum has 710 mg of salt, more than 4x the salt in a can of tuna fish! We eat all kinds of varied foods from all over the world but there's no way we could keep one of these down.
Are these really intended to be eaten straight, or is this a preservative, or a seasoning? One plum would be more than enough salt for a pot of soup. Or are they intended to be soaked and de-salted, like salt cod? The package did not give any instructions.
I've Googled around and there are numerous articles about the nutritional wonders of umeboshi, but I can't imagine that eating 700 mg of salt in one bite could possibly be good for you.