Characteristics
Overview
Spoiled Beef. Consuming will damage your health.
The raid took your battery room, not your kitchen. The raiders left the food alone, but the fridge was wired to those batteries, and by the time you had power again, the beef inside had turned. The game texts never say whether a fridge needs power at all. If yours stopped keeping food the day the batteries went, you have your answer.
What you pulled out is spoiled beef, and its text is plain: consuming it will damage your health. It stings more than losing other meat, because raw beef comes from livestock you cannot count on finding every wipe.
Bin it and test the fridge with one stack before you trust it again. Fresh beef from the next herd goes on a fire as soon as it reaches base, and the team eats cooked beef.