5 easy ways to keep apples from turning brown

• Apples turn brown due to a particular enzyme that's activated when the fruit is exposed to air.
• Soaking apples in certain liquids, like lemon juice and salt water, can delay this process.
• Storing apples in the fridge in a low-humidity crisper drawer can also prolong their freshness.

Biting into a juicy apple or cutting it into slices — only to find the fruit quickly turns brown — can be a bummer. But the truth is, this browning effect has nothing to do with freshness.

According to Aaron Browning, executive chef at Queenie's Supper Club, apples turn brown after being exposed to air because oxygen activates a specific enzyme in the fruit called polyphenol oxidase (PPO). This sets a chain of chemical reactions in motion that produce brown-colored pigments. It usually takes just 5 to 15 minutes for this to begin, says Browning, depending on how much PPO that particular variety of apple has.

"Oxidized apples that have browned are entirely safe to eat and can still be fresh, but many people find the appearance to be less appetizing," says Jessica Randhawa, head chef and recipe creator behind The Forked Spoon.

Since cutting apples exposes them to air, Browning advises only slicing them right before you plan to eat them.

Here are some other popular tactics for preventing apples from turning brown.

1. Lemon juice

According to Browning, this is one of the most effective ways to preserve apples.

Lemons contain high amounts of citric acid, which can help to completely deactivate the enzyme in apples that triggers browning. Randhawa recommends placing apple slices in a bag and tossing them with lemon juice (about 2 to 3 tablespoons per apple) until all surfaces are evenly coated.

Let them soak in the lemon juice for at least five minutes or until you're ready to use them. You can also use a vegetable brush to coat the slices.

While this strategy can delay browning for several hours, it also tends to alter the flavor, adding a tanginess that may not be suitable for all recipes. To prevent this, try soaking apples in a mixture of ¼ cup lemon juice and 1 quart of water.

Quick tip: If you don't like the taste of lemon juice, orange and pineapple juice are also very acidic and can have a similar effect.

2. Salt water

Sodium is a natural preservative that can keep oxygen away from the surface of the apple slices, says Randhawa. She recommends mixing ⅓ teaspoon table salt with 1 cup of water and soaking apples for at least 8 to 10 minutes. Browning says you can then store them in an airtight bag or container in the fridge for a day or so.

When you're ready to eat them, Browning advises giving the apples a quick rinse with tap water to wash away any salty flavor.

3. Honey water

Honey is another natural preservative, thanks to a particular compound that deactivates the browning enzyme in apples. The advantage of using honey over some other options is that it won't significantly alter the flavor of the apples. However, Browning notes that one potential drawback is that honey may add some extra sugar depending on how much is absorbed or left on the surface.

Experts recommend dissolving 1 to 2 tablespoons of honey in 1 cup of room temperature water and soaking apples in this mixture for one to five minutes before rinsing them under cold water. If you're not ready to eat them right away, refrigerate them in a plastic bag overnight and they should still be fresh.

4. Lemon-lime soda

Like lemon juice, Browning says lemon-lime soda also has citric acid that can stave off the browning process — but typically not as much as pure lemon juice.

Try soaking apple slices in lemon-lime soda for three to six minutes, then rinsing under tap water. This method should keep apples fresh for several hours, even at room temperature, and potentially longer if you store them in the fridge.

5. Plain water

If you're pressed for time or don't have any of the above ingredients, even just soaking apple slices in water can help delay browning a bit by minimizing oxygen exposure. Just submerge apple slices in room temperature tap water and seal them in a bag, eliminating as much air as possible.

Quick tip: Apples produce a gas called ethylene that can speed up the ripening process for many other fruits and vegetables when in close proximity, says Randhawa. Avoid storing apples with other ethylene-producing produce, like avocados, bananas, peaches, pears, kiwi, and peppers.

Can you freeze apples?

According to Randhawa, you can also freeze apples for later use — but since the texture may be compromised after thawing, she says this method is best when you're using the apples for baking or smoothies.

Browning recommends peeling and slicing the apple into eighths, then soaking the slices in a bath of 4 cups of water with 2 tablespoons of lemon juice for five minutes.

After draining them, arrange the slices on a parchment-lined baking sheet and freeze for four to ten hours. Finally, transfer the slices to a freezer bag labeled with the date. Frozen apples can last up to a year, says Browning.

Insider's takeaway

It's natural for apples to turn brown when exposed to oxygen, and they're still perfectly safe to eat. Still, if you want to delay this process, try soaking apple slices in lemon or pineapple juice, salt water, lemon-lime soda, or honey water. Even submerging them in plain water will do in a pinch.

Keep in mind that some of these solutions — particularly lemon juice — may affect the flavor of the apples, depending on how long they soak. However, you can rinse off the apple slices with tap water to help restore some of their natural taste.

Always store apples in the fridge in a low-humidity crisper drawer and away from other ethylene-producing fruits and veggies whenever possible to prevent them from ripening too quickly.