Scavenging.

[Clansmen63]

I am sure that there is a key to grocery store layouts (I seem to remember reading someplace) that some key was developed in order to make the customer walk through the store as it had been laid out in some way to lead from one item to the next (If this makes any sense to you). So if this is the case, find someone who works in grocery retail and ask them for the key, At least this way you would have a rough idea of the type of foods stuff likely to be in the tin relative to where it was placed in the store.

Though as has already been said, just take them all and open them later as required. Even if it is dog food or cat food and you didn’t want to eat it, it can be used as bait for other animals for your pot, such as hedgehogs love cat food, Mr. Fox is partial to some dog food etc. All tasty nutrition.