Preheat oven to 350 degrees.
Beat egg whites until frothy.
Add sugar, egg yolks, oil, vanilla, lemon juice and lemon rind, (or just juice if preferred).
Combine dry ingredients. Mix into wet ingredients.
Roll frozen blueberries in flour to coat. Reserve a handful of berries.
Fold rest of blueberries into batter.
Grease an angel food cake pan.
Put the handful of blueberries on bottom of pan.
Pour batter on top.
Bake at 350 degrees for 1 hour.
When cooled remove from pan and sprinkle with white sugar.