!!OMG!! - WOT'S in WOTSITS?!! PLEASE CAN 'YOU' EXPLAIN THIS....?!

A friend asked me to check one of his fav snacks under my trusty microscope, as he was concerned about black specks he noticed on them.
I have no specialties and so my naivety is to be expected...
Incredibly, I have never seen air bubbles through a microscope and so .....and:
I've since discovered that the black discs are, in fact, 'air bubbles' - but why they are black membraned, I don't really understand....Other than that - the rest - does appear concerning - black dots/magnetic, etc....