Banana - squashed, pureed, whizzed up, etc.

Iv just told my friend that a banana becomes syns if you puree it, squash it, or whizz it up, and she said that when you eat a banana, you chew it, and squash it, before you swallow....so what's the difference?? :sigh:

This has really made me want to ask why a banana has to be syned when it is broken down???