Why do people use lemon juice on fruit salad to keep it from browning?
Because the citric acid or ascorbic acid in lemons keep fresh cut fruits from browning from the air they are exposed to, also known as oxidizing. Limes have the same effect. There is a commercial product called fruitfresh which can be used for a substitute. See the related link for more information. This can also be used on apples, avacadoes, potato salads and any other salad that brown due to contact with air.
