I've worked in a "fresh" vegetable packing factory once... I'll go with frozen food. Stuff like broccoli came in from the fields in crates on pallets and were put in cold storage, probably not frozen but close enough, and stayed there until they were individually wrapped. Frequently one of the crates or a whole pallet was moldy and had to be discarded. I have no idea how long it must've been in the cold storage for that to happen.

The place burned down a few years later, anyway; they stacked up pallets as high as the factory itself right next to it, iirc someone lit it.