Good question, Jospeh; I never tried freezing it. But theoretically it should work. Though I would leave out the bananas as their PPO might still affect the polyphenols of the other fruits. Either you blend them in after thawing the smoothie (but I guess, you think of freeezing because you want to avoid having to mess with the blender again), or you leave them out entirely. I guess the texture will suffer a bit, but you can try.