Avocado slices can stay fresh and green for at least two days when wrapped tightly in cling film, as the plastic limits the fruit’s exposure to air, the primary cause of browning.
Cling film blocks oxygen
Avocados that have been cut are prone to browning due to a natural enzyme called polyphenol oxidase, which reacts with oxygen. Wrapping the fruit in cling film creates a sealed protective barrier, reducing the amount of oxygen that reaches the flesh. This slows down the browning process, keeping the fruit fresher for longer.
Food website advice
Food website Food Matters explains: “If we’re trying to prevent the oxidation of the avocado, cling film is a great choice. While it’s not entirely foolproof, and the use of single-use plastic is a growing burden on the environment, it’s a quick and easy option.
“Simply wrap the avo nice and tight (and that part is key) in the cling film of your choice. If you’re looking for a more sustainable option, try a reusable beeswax wrap.
“It is important to mention that this method proves quite successful for keeping guacamole fresh for a longer time. When storing it, gently press the wrap down onto the surface of the mixture in a bowl or container to remove all of the air, and you’ll have fresh guac for days.”
Additional storage tips
It’s also recommended that the wrapped avocado is placed inside an airtight container and put in the fridge, as the cold temperature helps the fruit stay greener for longer by inhibiting the enzymes that cause oxidation.
To help ensure freshness, you can also add a squeeze of lemon or lime juice to your avocado before storing it. These fruits contain citric acid, an antioxidant that inhibits polyphenol oxidase, which produces the brown pigment when it reacts with oxygen. Brushing the avocado flesh with lemon or lime juice creates a barrier that helps keep the fruit fresh and green, although it can slightly alter the overall flavour.
Experts at Real Simple add: “If the avocado is already sliced, your best course of action is to grab a food storage container. However, instead of using the corresponding top, cover the container with plastic wrap, making sure the wrap comes in direct contact with the avocado and there are no air pockets. This will help prevent oxygen from getting in and turning your bright green avo flesh brown.”
