The problem with bananas is buying them in a big bunch. Unless you’re hosting a banana-split-making party, it’s hard to get through the entire bunch before one or two start turning. The solution in my house is to only buy 2 or 3 bananas at a time and/or plan on putting a few in the freezer for future fruit smoothies.
There’s a company in Asia that has found a solution to this problem. I have no idea if their product is performing well or poorly, but I love the outside-the-box thinking: