Preheat the oven to 425 F. Line a 12-cup muffin pan with paper or foil liners.
In a large bowl, combine the flour, cornmeal, brown sugar, baking powder and salt. Stir to blend evenly.
In a separate bowl, combine the milk and egg whites. Add the apple and corn, whisk to mix evenly and pour over the flour mixture. Stir lightly until all are slightly moist. The batter will be lumpy.
Fill prepared muffin cups 2/3 full and bake about 30 minutes. Tops will spring back when touched.