New Technique
I put my store-bought bananas in one of my reused plastic produce or grocery bags. I push out the air from the bag and close the bag tightly. I have stored bananas up to five weeks in the refrigerator this way without the skins turning dark or the flavor deteriorating quickly.
I just recently ate one which had been on the lower or middle shelf for five weeks. It was fine.
I saved it an extra week longer, by itself, in the plastic bag even though I had eaten the rest of them for four weeks prior. Those prior ones tasted good throughout that four week period.
Process Explaination
One thing taking place is that the ethylene gas is still active but greatly slowed by the chill. They still continue to ripen, but much slower.
The bags shield the the bananas from dehydration and oxygen. Bananas which are not protected by this plastic bag, chilled storage method apparently get oxidized. If something gets oxidized by a flame, for example, it turns black. The bananas do something similar when they are exposed to too much cold without protection.
