Friends don't let friend's avocados turn brown.
If you’ve ever sliced open a ripe avocado and felt your mouth start to water, you know that there’s nothing more disappointing than when that same delicious flesh turns brown and unappetizing. Avocados contain an enzyme called polyphenol oxidase, which when in contact with oxygen in the air, causes avocados to turn brown. The best way then, to keep an avocado from turning brown, is to reduce its contact with air as much as possible and there are a couple of easy tricks for keeping that air away, and your avocados green, creamy and delicious.
The first? Leave the pit in the portion of the avocado you don't use! Making guacamole, toss a couple of pits into the mix to keep your dip vibrant green and be sure to add citrus acid from limes or lemons. If you're storing half an avocado, drizzle some lemon juice on the flesh and the pit, then wrap the avocado tightly in plastic wrap.
Voila! Mean, green and delicious avocados!