To prevent browning in fruits like bananas and apples, coat them with an acidic juice such as lemon juice, lime juice, or orange juice immediately after cutting. This inhibits the enzyme responsible for browning.
Browning, also known as enzymatic browning, occurs when enzymes in fruits react with oxygen in the air. This reaction causes the fruit to turn brown and can affect its appearance and taste. To prevent this, you need to inhibit the enzyme activity or create a barrier between the fruit and the air. Here's a step-by-step guide:
Prepare your acidic solution: Squeeze fresh lemon, lime, or orange juice into a bowl. You can also use pineapple juice or a diluted vinegar solution (1 tablespoon of vinegar per cup of water).
Cut the fruit: Slice or dice your bananas or apples as desired.
Coat the fruit: Immediately after cutting, toss the fruit pieces in the acidic juice, ensuring all surfaces are coated. For larger pieces, you can brush the juice onto the cut surfaces.
Storage (optional): If you're not serving the fruit immediately, store it in an airtight container in the refrigerator. This further minimizes exposure to oxygen.
The acidity in the juice lowers the pH level, inhibiting the enzyme polyphenol oxidase (PPO) that causes browning. The coating also acts as a barrier, preventing oxygen from reaching the fruit's surface.
Use a minimal amount of juice to avoid altering the fruit's flavor too much. A light coating is usually sufficient. Also, consider using pineapple juice, as it contains bromelain, an enzyme that can further inhibit browning.