Hi D
As an emergency; frozen food and pre cooked food is fine and I have broken a few of my own 'rules' on more than one occasion, but *ideally* the food should be uncooked and unfrozen.
Cooking a food and freezing a food denatures some of the essential vitamins, proteins etc that is found in the food. Okay, I am no nutritionist but its a fact that, even for humans, the best way to eat a food is raw. Perhaps googling for human foods and freezing/cooking will be helpful?
SanV - yeah the krill from a shop is raw but frozen. Ideally, cephalopod food should be fresh and raw, do you have a seafood shop near you?
cheers
Colin