6 Simple Methods to Prevent Apples from Browning

Have you ever cut into an apple only to see its flesh start to darken right before your eyes? Here’s how to prevent that from occurring.

Imagine this: You’ve just brought home a bounty of fresh apples from the farmers market, envisioning all the delicious dishes you’ll create (think apple pie, applesauce, or caramel apple cheesecake!). Eager to indulge, you slice into one of those beautiful apples and admire its juicy, pristine, and crisp interior. But as you reach for the peanut butter, you glance back at the cutting board and are dismayed to see that the flesh has already begun to brown.

Regardless of how fresh your apples are, once sliced, they can start browning in as little as two minutes. What causes this beloved autumn fruit to spoil so quickly? While it’s impossible to stop the browning completely, there are effective ways to slow it down.

Home chefs have devised numerous inventive techniques to keep their sliced apples looking fresh, including applying lemon juice, or soaking them in honey water or lemon-lime soda. But which of these strategies truly work? We’ll delve into that shortly, but first, let’s explore why your perfectly ripe apple is changing color in the first place.

What causes sliced apples to turn brown?

Tenley Fitzgerald, the marketing vice president at Yes! Apples, a consortium of apple farms in New York, attributes this discoloration to a phenomenon known as enzymatic browning. To delve deeper into this topic, I consulted Christopher Watkins, a professor at Cornell University’s School of Integrative Plant Science Horticulture Section, who specializes in apple quality and storage longevity. Watkins clarifies that the browning occurs when naturally occurring phenolic compounds in the apple react with an enzyme called polyphenol oxidase (PPO). “Under normal conditions, phenols and PPO reside in different areas within the cell,” he says. However, slicing the apple damages the cellular membranes, enabling these components to interact. The PPO enzyme triggers a reaction between the phenolic compounds and oxygen, leading to the formation of brown-colored melanins—similar to the melanin responsible for pigmentation in human skin.

But what accounts for the differences in browning rates among apple varieties? Each type of apple has distinct levels of these compounds. “Some varieties may have high levels of phenolics but low enzyme activity, or vice versa,” Watkins notes. Additionally, antioxidants influence this process by slowing down the chemical reactions, which means apples rich in antioxidants tend to brown more slowly.

While brown apple slices may not be visually appealing, they are still safe to eat

McIntosh, Golden Delicious, and Fuji apples tend to brown fairly quickly, while Honeycrisp and Snapdragon apples exhibit a moderate browning rate. In contrast, Pink Lady, Empire, and Cortland varieties are known for their slow browning. According to Watkins, “Browning resistance can be genetically inherited through apple breeding programs.” Many well-liked apple types, such as the white-fleshed Pink Lady, are the result of these crossbreeding efforts. Interestingly, only one apple variety—Arctic apples—has been genetically modified to prevent browning altogether. This underscores the importance of selecting your apples carefully.

Additionally, environmental conditions like temperature and oxygen levels significantly influence how quickly an apple slice browns. Greater exposure to oxygen accelerates browning, while cooler temperatures slow down the process, as explained by Watkins.

Here are six effective strategies to prevent apples from browning:

When using apples in baking recipes like pies or crisps, browning isn’t a major concern since they will brown further during cooking. However, if you’re aiming for visually appealing slices for a charcuterie board, an apple tart, or lunches for kids, consider employing one of the following techniques to decelerate oxidation.

Keep in mind that these methods for maintaining the whiteness and crispness of apple slices are only temporary: all sliced apples will eventually brown (unless they are the genetically modified variety). It’s simply part of nature. Accept it. Although browned apple slices may not be the most attractive, they remain perfectly safe to consume. Fitzgerald notes that “browning does not alter the flavor of the apple or indicate spoilage.”

1. Select a low-browning apple.

To start off, it’s crucial to pick the right type of apple. Watkins recommends opting for varieties that are less prone to browning, such as Pink Lady, Empire, Cortland, RubyFrost, Ambrosia, Ginger Gold, or EverCrisp.

2. Immerse in Water.

One of the simplest ways to prevent apple slices from turning brown is to limit their exposure to air. There are various methods to achieve this (like using a rubber band to hold the slices together), but our preferred approach is straightforward and doesn’t require any special skills or tools. Just dip your apple slices in plain water. According to Watkins, “Water serves two purposes: it cleanses damaged cells and, more importantly, lowers the oxygen levels surrounding the slices.”

To do this, take a medium bowl filled with cold water and place your apple slices inside. Since they tend to float, cover the surface with a clean paper towel. The weight of the soaked towel will help keep the apple slices submerged.

3. Immerse in Saltwater.

Using salt as a preservative can help maintain the fresh appearance of apple slices. Simply dissolve ⅛ teaspoon of kosher or table salt in 1 cup of water. Add your apple slices and let them soak for 1 to 3 minutes (be cautious not to leave them too long to avoid a salty taste), then drain in a colander and rinse with fresh water.

4. Immerse in Honey Water.

According to Epi contributor Sheela Prakash, honey contains a compound that inhibits the enzyme responsible for browning. Mix 2 tablespoons of honey into 1 cup of water and soak your apple slices for 1 to 3 minutes. After soaking, drain and optionally rinse with fresh water (or skip rinsing if you prefer the honey flavor).

5. Apply Lemon Juice.  

As we mentioned earlier, apples rich in antioxidants are slower to brown. Even if you’re using apples with fewer antioxidants, you can apply a high-antioxidant ingredient like citrus juice to minimize browning.

A widely used technique for preventing browning is to rub the apple slices with lemon juice, which is a source of ascorbic acid (vitamin C). Watkins notes that commercially, apple slices are often treated with ascorbic acid to prevent discoloration. Any citrus juice - be it lemon, lime, orange, or even pineapple juice - will work because these juices contain citric acid that slows down the chemical reactions leading to browning. You could also sprinkle powdered citric acid on the fruit, though it might impart a strong sour taste.

If you choose to soak the apples, add 2 tablespoons of lemon (or another citrus) juice to the water for added protection against browning. Let them sit in this lemon-infused water for 1 to 3 minutes before draining and rinsing. Alternatively, you can directly squeeze lemon, lime, or orange juice onto the cut surfaces of the apples; keep in mind that this may give them a slight citrus flavor.

Bake those slices into an apple pancake and no one will be concerned about their color.

6. Store Apples at Low Temperatures in an Airtight Container.

To effectively prevent browning in apples, it’s crucial to limit their exposure to air. After employing one of the aforementioned techniques, store the treated apple slices in an airtight container or a resealable plastic bag with as much air removed as possible. While this helps reduce browning, Watkins cautions that if apples are deprived of oxygen for too long, they may ferment.

Keeping cut apples in the refrigerator will also aid in preserving their color. If you leave sliced apples at room temperature, they will brown significantly faster than if stored in a cooler environment. The lower temperatures slow down enzymatic reactions that cause browning, allowing you to keep cut apples in the fridge for up to 6 hours without concern.