Preheat oven to 350 F. Spray a 9x5 loaf pan with Pam.
Sift together flour, salt, baking soda and baking powder together in a mixong bowl, Set aside.
In a large mixing bowl, cream butter and gradually beat in sugar until light and fluffy. Beat in egg whites one at a time.
Alternate the flour mixture and bananas to the wet and mix thoroughly until blended.
Fold in fresh blueberries.
Transfer to a 9x5 loaf pan and bake 45-60 mintues or until a toothpick comes clean in center.
Enjoy ! It is fabulous!