Storing Apples at 30F?
This temperature range would be a compromise between a very low temperature needed to limit natural decay or decay triggered by micro-organisms (the lower the temperature, the lesser the decay) and the formation of destructive ice crystals.

Only pure water freezes at 0°C (32°F) under atmospheric pressure. But the content of apple cells and cell walls is a rather complex aqueous solution, containing many natural cryoprotectants, among which the fruit's sugars. Therefore, the freezing point of apples might be as low as 30°F.