>>3774521How to keep bananas fresh
Two of the easiest ways to keep your bananas fresh is to:
Wrap the stems with plastic wrap. This method slows down the release of ethylene gas, which is responsible for ripening fruits.
Dip them in lemon juice or orange juice will prevent sliced bananas from browning. The citric acid in the juice helps to slow down the oxidation process, keeping the bananas looking fresh for longer.
What if your banana isn't ripe enough? There's a hack for ripening it, too! Preheat your oven to 300°F. With the peel still on, place the banana directly onto the oven’s baking rack. Check on the banana after 5 minutes. If it hasn't ripened enough, wait 5 more minutes or until the peel is dark brown. Let the banana cool for a few minutes before using it. The oven will help caramelize the sugars in the banana, making it sweeter and more flavorful.
https://www.msn.com/en-ca/foodanddrink/foodnews/how-to-keep-bananas-from-turning-brown/ar-AA1GDYeK?cmp_prftch=2&ocid=msedgntp&pc=U531 