Amazon free books are excellent on how to test meat.
FTA: The use of spices and their importance has contributed to the misconception that it was common to use them to disguise the taste of rotten meat. However, this was an uncommon practice perpetrated by underhanded butchers and vendors
I have bought at supermarkets some bad meat, almost always hamburger. They use smell proof plastic so I buy from the meat counter any hamburger if I can. I order groceries from home now and always put in the notes FRESH MEAT