6 Ways to Help Keep Avocado From Turning Brown

1. Wrap it or store it in an airtight container

Once avocados are cut, the PPO and a group of antioxidants called phenolic compounds found in the pulp are exposed to oxygen. The phenols then transition into pigment-creating compounds called quinones.

Then, quinones and their byproducts go through several reactions, forming the brown pigment.

This means that the enzymatic browning reaction is only triggered when PPO, phenolic compounds, and oxygen come in contact with one another. Thus, it can be preventedTrusted Source by removing oxygen from the cut surface.

Wrapping a cut avocado in plastic wrap or storing it in an airtight container may control oxygen exposure and delay browning.

However, keep in mind that the browning can resumeTrusted Source again you remove the avocado from the container and expose it to oxygen again.

2. Add lemon juice

Because PPO is crucial for controlling browning, targeting other factors that influence PPO’s activity may also helpTrusted Source prevent browning.

Aside from oxygen, modifying pH levels is another helpful way to keep your avocados from browning.

Since PPO is active at pH levels between 6–7.5 but inactive below pH 3, one way to influence PPO is through applying acidulants — chemical compounds that help lower pH levels.

Acidulants, such as citric and ascorbic acid found in lemon juice, help lower the pH of avocados and decrease the enzymatic activity, keeping them from turning brown.

Squeezing a little lemon juice on top of your cut avocado before storing it could help delay browning.

3. Store with an onion

Evidence shows that onion extract may preventTrusted Source enzymatic browning by inhibiting PPO activity.

ResearchersTrusted Source believe that since PPO is a copper-containing enzyme, onion’s sulfuric compounds and their derivatives may interact with copper at the enzyme’s active site and hinder its activity.

In fact, compounds containing a sulfhydryl group may disruptTrusted Source PPO-induced browning by up to 33%.

Storing your cut avocado with a sliced onion may also keep it from browning without affecting its flavor — as long as you make sure that the onion only remains in contact with the skin of the avocado and not the pulp.

4. Submerge in coconut water

Another way to keep your avocado from turning brown is by submerging it in coconut water.

Aside from limiting oxygen exposure, the antioxidant content of coconut water seems to play a roleTrusted Source in delaying PPO’s enzymatic reaction.

However, you may not want to leave your avocado submerged in water for too long, as it can lose its firmness and become mushy. This might be a useful technique when you only need to store an avocado overnight.

5. Add pineapple juice

As with lemon juice, coating your avocado with pineapple juice may keep it from turning brown.

In fact, two potential mechanisms explain the effect of pineapple juice on PPO.

Evidence suggestsTrusted Source that pineapple juice is comparable to sulfite — a widely used anti-browning agent that inhibits enzymatic browning. Pineapple juice’s browning-inhibition properties may alsoTrusted Source be a result of its antioxidant content.

Brushing a bit of the juice on your avocado’s exposed pulp may help delay browning.

6. Coat with honey

Adding a thin coat of honey to the surface of your cut avocado may also help delay avocado browning. Honey acts as a barrierTrusted Source that helps limit contact with oxygen while inactivating the PPO enzyme at the same time.

There are two proposed mechanisms behind honey’s effect on PPO’s activity.

Similarly to onions, antioxidants in honey may interfereTrusted Source with copper in the PPO active site, which would block the enzyme’s activity.

The second potential reason is that the presence of small peptides (amino acid chains) in honey reducesTrusted Source quinones, which would otherwise go through multiple reactions leading to the formation of the brown pigment.

Is it safe to eat an avocado after it’s browned?

Enzymatic browning creates a condition that affects the quality of avocados by deteriorating their nutritional and sensory properties.

However, avocados are safe to eat after they’ve turned brown. Just remove the browned surface, and you should still be able to enjoy the rest.

Nevertheless, if your avocado has an odd smell, it may indicate the presence of microbial deterioration, in which case you should discard it.

The takeaway

Avocado browning is a natural process that happens once you cut into it. This is due to the activity of an enzyme called polyphenol oxidase (PPO).

However, it can be delayed. Some of the ways you can prevent avocado browning are by wrapping it thoroughly, adding lemon or pineapple juice, or storing it with an onion.

While avocados are safe to eat after they’ve turned brown, their quality may be reduced. Be sure to discard them if they start to smell bad.