2. Soda Water
Soda water or club soda is known for its ability to preserve freshly sliced fruits. Best of all, it doesn’t affect the taste of the banana. Use it as you would use fruit juices, soaking the slices in the soda water before serving or storing them. Tonic water, a beverage that looks the same, has a strong flavour that doesn’t go well with bananas.
3. Diluted Citric Acid
Citric acid (the same chemical that makes citrus fruits like lemons sour) is sold in a purified form as a canning additive. In this form, it is specifically used to keep stored fruits from discolouring. To use citric acid, add three teaspoons to a cup of water and blend. Soak the slices in the bath as normal. Please keep in mind to not use undiluted citric acid, as it is far too sour.
4. Diluted Vinegar
Vinegar can be used in addition to citric acid to keep fruits fresh. However, its sturdy sourness also makes it important to dilute it. As with citric acid, add a few teaspoons to a cup of water to make a bath and soak the banana portions as normal.
5. Limited Exposure to Air
Since banana slices turn brown when they are exposed to the oxygen in the air, preserving the fruit from physically touching the air will save you the browning reaction from occurring. One easy trick involves wax paper. Cut the slices so that they are all about the same slice and then lay them on a tray. Cut a square of wax paper to fit the tray, then lay it down over the slices and gently press it down so it sticks to each. The banana slices will be sandwiched between the paper and the tray without any air exposure. If you have a vacuum storage device you can also try packing the slices in an air-free container. To preserve whole bananas, cover the stalk with foil paper to prevent exposure to air.
Now that you know these tricks, you can easily buy more than 3-5 bananas a day