Yes, as long as you cook the mango first! You shouldn’t let frozen foods thaw, puree and re-freeze without cooking them. So if you use frozen mango to make the puree, serve immediately or store in the fridge for a few days, but do not freeze it again unless you cook it. If you cook the frozen mango (simmer or steam on the stovetop) and then puree it, it will be safe to freeze.