Once peeled and cut, fruits like apples and bananas can start to turn brow. Generally, the way to prevent this is by tossing the fruit in acid such as lemon juice, or, for a less tart option, pineapple juice.  In this creamy fruit salad recipe, the yogurt is acidic, and it is mixed with orange juice. That is why making a fruit salad with yogurt dressing will prevent the fruit from turning brown rapidly. I still recommend eating it within a couple of days.