Salt water beats lemon juice for keeping cut fruit from browning.

Salt water is the best trick for keeping sliced apples from browning in a lunchbox.

Those apples go brown because the cut surface reacts with oxygen. A quick soak in lightly salted water stops that enzyme reaction for a few hours, and as long as you don’t go overboard, it doesn’t make the fruit taste salty.

Use about half a teaspoon of salt per cup of water, let the apple slices soak for 3–5 minutes, drain them well, and pack them like normal. Honey water also works — two tablespoons of honey dissolved in a cup of water — but salt water is cheaper and faster. Lemon juice works too, but it can leave a tangy flavor that overpowers the fruit.

Do this in the morning, pack in a small airtight container, and your kid’s apples should still look white at lunch. If you’re packing for a long day, nobody’s trick is perfect, but salt water buys you more than enough time.