Tomato skins are often removed because of their texture, but I've come across a few exceptions. Some dishes that involve boiling whole tomato, such as when cooking rice or making broth. This sidesteps the texture issue and requires less work, which may be enough of a reason, but I've heard claims that it contributes more.
I couldn't find a clear answer to what it contributes, exactly. Tomato skins apparently contain more pectin than the pulp, so it may act as a thickener. I also came across a few stray comments mention that it will add bitter and/or umami flavors.
Is there a well established purpose to boiling tomato skins? Does it thicken liquids or contribute a different flavor profile compared to the pulp?
