While a browned avocado is safe to eat, there’s no disputing its lack of appeal. The verdant hue of the fresh fruit makes for much prettier guacamole, tacos, toast, and sandwiches.
Cooking Tips
We Tried 11 Ways to Keep Avocados from Browning
From blanching to vacuum sealing to a dip in onion juice, we tried every trick in the book. Here’s what actually worked.
By and
Published May 21, 2024.
But avocados brown rapidly, and while there are many tricks across the internet for staving off that transition, some of them are pretty impractical, and some don’t even work at all.
We wanted to crown a winning avocado preservation method once and for all. So we devised a game plan with the help of Senior Science Research Editor Paul Adams, gathered a case of avocados, and headed to the kitchen.
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Why Do Avocados Turn Brown?
Avocado discoloration is the result of a series of reactions that occur when an enzyme called polyphenol oxidase (PPO) causes a class of compounds called phenols to react with oxygen.
These reactions require air and occur most readily when the pH is between 5 and 7. One of their end products is melanin, a brown pigment.
Broadly speaking, an avocado’s enzymatic browning can be prevented through four methods:
- Damaging the PPO
- Limiting the amount of oxygen present
- Changing the pH
- Introducing compounds such as antioxidants that preemptively react with oxygen
Help! I Cut My Avocado Too Soon. Will It Still Ripen?
Good news: If you store it properly, a cut avocado will continue to ripen and be just as creamy as if you'd opened it at peak ripeness.11 Possible Ways to Prevent Avocados from Turning Brown
Armed with the knowledge of what causes avocado browning, we put the following strategies to the test:
Methods that damage the PPO:
- Dipping in grain alcohol
- Dipping the cut side in boiling water for 10 seconds
- Dipping in onion juice
Methods that limit oxygen:
- Wrapping tightly in plastic wrap
- Vacuum sealing
- Submerging in water
- Submerging in oil
Methods that react with oxygen:
- Dipping in vitamin E oil
Methods that react with oxygen and change the pH:
- Dipping in an ascorbic acid solution
- Dipping in lime juice
- Dipping in lemon juice
One Sure-Fire Way to Keep an Avocado Green
Only one method staved off every speck of browning, and that was vacuum sealing. Enclosed in this airtight environment, avocados stayed a pristine green for 5 days. But even if you have a vacuum sealer, who wants to haul it out and use a whole bag to stave off a little browning?
The Best (and Most Practical) Way to Prevent Avocado Browning
The other methods didn’t prevent browning entirely (and one method, blanching, flat out failed). Most also came with significant side effects.
Lemon and lime juice and ascorbic acid worked well enough but made the avocado taste sour. And putting the avocado face down in water or oil were decent methods, but the first turned it mushy and the second greasy. And making onion juice just for the sake of keeping an avocado green is impractical, to say the least. Ditto for rounding up vitamin E oil and grain alcohol.
For our money, tightly covering the avocado with plastic wrap and refrigerating it is the best method. It’s easy and practical, and while it won’t keep an avocado totally green, we found the discoloration was minimal. Plus, there’s zero flavor change.
Here’s a chart of our results.
