When bananas are exposed to temps below 45, you can pretty much guarantee the gray discloration will show up. I am not sure how much time they need of exposure at this temp. This is a great topic….maybe some expert will write in.

Many thanks to Mark Levin, of M. Levin Co., Inc, a major banana wholesaler from Philly. Mark wrote:

“Riding bananas with other fruits and vegetables this time of year does create problems. If you can balance the temperatures to be a little higher than normal (instead of 36….try riding the load at low to mid 40’s..)..Also we cover the bananas with newspaper individually to try to keep them warmer….They also make a plastic bag which fits over the whole pallet so as to keep it warmer and keeps the gas inside so the ripening process does not get disturbed as much.”

bananas should not be exposed to temps lower than 55 F or higher than 65F
Light-medium chill injury will occur after about an hour at 52F, after about 4 hrs at 53F, and after 12-24 hrs at 54F
You will see brown discoloration just under the peel

Thanks for the help with the chilling question! Very much appreciated.

My experience, and it was quite some time ago was that low temperatures hurt unripe bananas more than ripe ones. Consequently the exposure curves need another dimension, state of ripeness to be accurate.

It can be very hard for some people to be able to see the discoloration, especially as the bananas ripen. Its easier to see in green bananas.

If you have not very ripe, but chill damaged bananas, covering and putting some ripe bananas under the cover can help. I think that chill damaged bananas create less ethylene, although I am not sure of this.

I have not wholesaled produce in 45 years although I still am eating it.