The book Ultra-Processed People by Chris van Tulleken really opened my eyes about UPF. I highly recommend it. Here is a video of him delivering a lecture at the royal institution about the topic: https://m.youtube.com/watch?v=j1oOoYnCfJs
I don't think adding kombu to dashi would count as UPF according to the book's definition.
I don't think adding kombu to dashi would count as UPF according to the book's definition.