If you didn't take it, then your buddy did. Stuff doesn't just "despawn" from chests.

That being said, look around and see if maybe it's in a different chest, or something. The number of times I've moved stuff around or dumped what I'm carrying in a chest in a weird place is beyond counting; at this point, I'm surprised my wife doesn't slap me in the back of the head every time she walks by my desk, just on principle.

And all of that being said... just make some more. It's not difficult, and only barely time-consuming... unless you haven't bothered marking all the foraging spots on your map when you're wandering around, so you have no idea where to get more blueberries or whatever... and even then, that's on you for not prepping correctly.

Don't get bent out of shape over a few stacks of food; stuff happens.