How to freeze mango puree

The basic idea is that you want to reduce the ice crystals formed while freezing the food. Here is what I would suggest.

1. Put a metal pan in your freezer for 30 minutes to cool.
2. Prep your zucchini, trying to get the most surface area possible.
3. Spread out, trying to not overlap on your pan and place back in the freezer for about an hour.
4. Place in your freezer bag and seal with as much air out of it as possible.

A completely ideal way to freeze almost all veggies or fruits is to get a cooler and some dry ice, place your cut pieces in a metal bowl inside your cooler and leave it while the dry ice does its magic. You will have minimal ice crystals while giving you the closest taste from the original.

Yes, I've done this. The key is to ensure that the jam isn't filling the glass container completely so that as it freezes it has room to expand.

I used a typical Ball canning jar, which sealed well enough to keep ice crystals out for several months.

From what I understand, freezer canning is useful when you don't have a pressure canner but want to can lower acid items which otherwise might be dangerous to your health (if not pressure canned).