Whole Wheat Blueberry Waffles

2 cups buttermilk
1 cup whole wheat flour
1 cup all-purpose flour
1 tablespoon sugar
3 tablespoons vegetable oil
2 teaspoons baking powder
1 teaspoon grated orange peel
1/4 teaspoon salt
3 egg whites or
1/2 cup cholesterol-free egg product
1 cup fresh or frozen (thawed and drained) blueberries

Heat waffle iron; brush lightly with oil if necessary. Beat all ingredients except blueberries just until smooth. Stir in blueberries. Pour batter from cup or pitcher onto hot waffle iron. Bake about 5 minutes or until steaming stops. Remove waffle carefully.