Apples selected for fresh applications should generally be more sweet than sour. Ideally, they will be firm and crisp, and more important, they should not brown quickly. Traditional choices for fresh presentations include Cortland and Golden Delicious. Newer varieties that work well include Cameo and Fuji.
If apples are old or have been stored improperly, they will brown more quickly than if freshly harvested. To further preserve whiteness, dip apples first in water enhanced with a small amount of lemon juice. The lemon juice slows the activity of enzymes that cause browning. Ascorbic acid (vitamin C) is sometimes used for this purpose, as well.