Why do bananas soften on the inside but stay green on the outside?

Question

Please advise on what factors could cause bananas to soften on the inside but remain somewhat green on the outside even after ripening with ethylene, i.e. the edible part of the banana is ripe/soft while the peel/skin shows no or little signs of ripening? (C.P.)

Answer

Exposure of bananas to temperatures above 30 C before and/or during ripening can inhibit ripening of the peel more than the flesh (edible portion).

Another possible reason for the disconnect between peel and flesh ripening is exposure to chilling temperatures between 10 and 13 C before ripening with ethylene.

                                                        
—Adel A. Kader