
Rio has long been famous for its fruit juice bars. Any time of day or night you'll find cariocas bellying up to the bar - so to speak - to get their daily dose of natural vitamins. A couple of tropical fruits native to Brazil, cashew and acerola, pack more vitamin C than any other fruit. Then there's pineapple, passion fruit, mango, cupuaçu, etc. etc. I never miss a chance, and was once the butt of a friendly joke. I asked for a passion fruit juice and the guy helping me shouted to the back "the lady here wants a tranquilizer" (in Portuguese "um calmante," because of the known calming properties of that fruit). It was so unexpected that everyone started to laugh. But that's typical of Rio, I think, where everybody has a stand-up comic inside, just waiting for the right moment to pop out...
The "in" thing is to eat a bowl of açaí, a little black berry from a palm that grows wild in the Amazon. It is a great source of vitamins and energy. It is now available in the U.S.
Also, if you're in luck, you may find fresh pitanga juice. This is the tiny fruit from a tree native to Barbados, called "pitangueira" in Portuguese. It turns a deep dark red when ripe and it's quite tart. The pitangueira grows all over Brazil, from the North to the extreme South, and it's one of the things I miss the most. (It's in season in October, November, just like the jaboticaba.)