How to Help Prevent Cut Avocados from Darkening
To prevent cut avocados from turning brown, cut them lengthwise in half and remove the pits. Place avocado halves, cut-sides down, in a shallow dish partially filled with water mixed with a few tablespoons of lemon juice. Refrigerate up to 12 hours. It's a great way to prepare avocados ahead of time for salads. Cut avocados as desired just before serving.