To keep an apple slice from turning brown, you put something acidic or a light protective coating on it, like lemon juice, salt water, or honey water.

Quick Scoop

Here are easy things you can put on apple slices to slow browning:

  1. Lemon juice (or other citrus juice) 🧃
    • Lightly brush or toss slices with lemon, lime, or orange juice.
 * The acid lowers pH and slows the browning enzyme (polyphenol oxidase).
  1. Salt water (very mild)
    • Mix about 1/2 teaspoon salt in 1 cup cold water, soak slices for a few minutes, then drain and rinse.
 * This helps block the browning reaction without leaving them too salty when rinsed.
  1. Honey water
    • Stir about 1 tablespoon honey into 1 cup water, soak apple slices for ~5 minutes, then drain.
 * Honey can help neutralize the browning enzyme and adds slight sweetness.
  1. Pineapple or other citrus-based juices
    • A quick dip in pineapple, orange, or lemon-lime soda can also slow browning because of their acidity and vitamin C.
  1. Commercial fruit-preserver (citric/ascorbic acid)
    • Products made from citric or ascorbic acid can be sprinkled or mixed with water and used as a soak.
  1. Plain cold water + airtight storage
    • Even just keeping slices submerged in cold water and then storing in an airtight container slows contact with oxygen.

Mini how-to (example)

  • Slice your apple.
  • Mix 1 tablespoon lemon juice with 1 cup cold water.
  • Soak slices for 3–5 minutes, drain, and pat dry.
  • Pack in an airtight container or bag.

They’ll stay looking fresher for hours, especially for snacks or lunchboxes.

TL;DR: Put something mildly acidic or a light honey/salt solution on the apple slice—lemon juice, salt water, or honey water are the most common kitchen fixes to keep it from turning brown.

Information gathered from public forums or data available on the internet and portrayed here.