This information might change your life. To prevent an avocado from browning, spray it with a little bit of cooking spray. When I first heard of this concept [1], I wasn't sure if it was true. But I tried it myself. I ate half an avocado and sprayed the remaining half with Pam. Then, I covered it with foil and refrigerated it. Days later, I pulled the avocado from the fridge and was shocked it see it was not brown at all. Seriously, try this; it's amazing!