Photo: Sergio Sergo (Shutterstock)
TikTok recently discovered a scientific truth about avocados: the green flesh of a cut avocado won’t turn brown overnight if it isn’t exposed to air. Unfortunately, the hack that’s supposed to protect your avocado is an unsafe one, according to the FDA.
TikTok after TikTok shows people discovering to their amazement that a cut avocado stored in a container of water on the counter is still green after a day, or even a couple of days. Another variation on the hack is to store whole avocados in water in the fridge, where they’re supposed to stay good for weeks. (We even covered a similar hack earlier this year, so we can’t feel too superior.)
Why you shouldn’t store avocados in water
A spokesperson from the FDA told Good Morning America that the avocado-in-water-hack is actually a terrible idea. The skins of avocados can contain pathogens like Listeria and Salmonella, although normally these would only be present in small amounts. Rinsing the avocado before preparing it, and scrubbing it with a produce brush (if you don’t have one, you really should get one) will normally remove enough of the potential germs that they shouldn’t be an issue.
When you store an avocado in the fridge for weeks, though, those bacteria can multiply. Listeria is notoriously good at growing in refrigerator temperatures, which tend to slow the growth of other kinds of bacteria. Listeria can cause mild food poisoning in healthy adults, but is especially dangerous to babies if you contract listeriosis while pregnant.
After the avocado has spent a few days in the fridge, washing it is no longer likely to remove enough bacteria to keep it safe. FDA studies have found that when avocados are stored under water, bacteria from the skin can make their way into the edible flesh of the avocado, where it’s not possible to rinse or scrub them off.
How to keep a cut avocado from turning brown
Fortunately, you can keep a cut avocado from browning without dunking it in water at all. The reason avocados brown is that oxygen reacts with chemicals in the flesh, so all you have to do is either keep oxygen away from the cut surface of the avocado, or interfere with the chemical reaction that causes browning. Here are a few ways to do that:
Lemon or lime juice will interfere with the chemical reaction, since it contains antioxidants like citric acid and vitamin C. Simply coat the cut surface of the avocado with a little tart citrus juice. (Pro tip: this works for apples, too.)
Plastic wrap is another quick and easy way to stop avocados (and even prepared guacamole) from browning. Just press the film into the surface of the avocado, making sure not to trap in any air bubbles.
Spray oil can do the same job as plastic wrap: spritz the avocado, giving it a thin layer of oil that will keep oxygen away.
