Lightly coat thirty-six 1-3/4-inch muffin pans with nonstick cooking spray; set aside.
In a medium bowl, stir together flour, sugar, baking powder, and salt. Make a well in center of flour mixture; set aside. In another bowl, stir together egg whites, orange juice, oil, and vanilla. Add egg white mixture all at once to flour mixture; stir just until moistened. Fold in blueberries. Spoon into prepared muffin cups, filling each about 2/3 full. Bake in a 400 degree F oven for 15 to 18 minutes or until golden and toothpick inserted into centers comes out clean. Cool in pans on wire racks for 5 minutes; remove from pans. Serve warm. Makes 36.