Cooked properly, a beef tenderloin is a sensory delight. It is cut from the most tender part of the animal and should have a fair amount of delicate marbling to add to the lovely texture. Like any meat, though, beef tenderloin is only delicious if it is fresh, not spoiled. A spoiled tenderloin is not only unpleasant to look at and smell, it is also dangerous to eat because of the bacterial growth. Determining whether a tenderloin is fresh enough to eat doesn't require any special instruments, just your eyes, hands and nose.
Remove the tenderloin from any packaging. This can mask the signs of a spoiled tenderloin, such as smell and texture.
Examine the meat visually, taking care to look at all portions of the tenderloin. If there are any discolored or moldy spots the tenderloin is not safe to eat and should be discarded.
Smell the tenderloin, noting any bad or off smells. Fresh beef has very little scent. If there is a scent, rinse the meat under a cold tap and smell it again, to make sure the scent is coming from the meat and not a result of the packaging.
Touch the tenderloin. If there are any overly mushy or hard spots, the tenderloin might be spoiled.