Is the un-moldy part of tomato paste still safe to eat?
I would take caution before consuming the sauce. It is possible that you may have killed mold however there could still be toxins. There are a lot of variables in these types of situations, such as whether or not those who are consuming the sauce have an allergy to mold. That is why a typical response is when in doubt, throw it out. I would say if you insist on keeping it taking a very small taste and give it about 30 minutes and see if you start developing a rash, throat starts feeling itchy / funny. But this can be extremely unsafe and I would advise against it.