Combine the flour, oat bran, sugar and baking powder and stir to mix well. Crush the orange segments slightly and add the oranges and their syrup, the egg whites and the vanilla to the flour mixture and stir just until the dry ingredients are moistened. Fold in blueberries. Fill muffin tins 3/4 full and bake at 350 for 15 to 18 min. Let sit 5 min.