Adding protein to smoothies

I bought some egg whites in a carton that had some interesting smoothies recipes.  I've tried to add protein powder to smoothies, but they either alter the taste or texture, ruining the sweet fruit flavor that I like.  Egg whites in a carton don't really have any taste, and since they are pastuerized you can add them straight into the smoothie.  I generally don't use a recipe when I make smoothies (it's easier just to dump everything into the blender and mix), but here are the recipes from the egg white carton.

Basic
1/4 cup egg white
1/2 cup ripe banana, chopped
1/2 cup fruit juice
1/4 cup low-fat vanilla yogurt

Berry Powerful
1/4 cup egg white
1/2 cup frozen raspberries, blueberries or strawberries
1/2 cup cranberry juice
1/4 cup low-fat vanilla yogurt
1 tbsp liquid honey

Peachy cream-free (no fat, no lactose)
1/4 cup egg white
1 peeled, pitted peach, chopped
1/2 cup orange juice
1/4 silken tofu
1/2 tsp grated fresh ginger

Skinny Mini
1/4 cup egg white
1/2 cup chopped honeydew or cantaloupe
1/4 cup lime juice and water
1/4 tsp cardamom
1 tsp liquid honey

My favorite smoothie is strawberry banana with yogurt and milk, now I'll add egg white to it as well.