Every time I think of things I miss from Brazil, I get a sweet taste in my mouth and a parade of tropical fruits in my mind... Fruits are a very important part of our diet and we always associate them to vitamins and cure of illness. If you feel weak, you should have some guaraná and-or açaí. If your metabolism is too slow, eat some papaya, or if it is too fast, eat some guava. If you have a cold, time for lime and cajú! and always have freshly squeezed orange juice! anyway, I found a webpage that has all that, but it is in Portuguese. However, no need to panic, enter the url in the babelfish page and you will have it translated (click on each fruit to see the translation, the names will not be translated, but descriptions are). I have checked the translation and it is good enough.
I recommend you do some homework and practice your fruit knowledge before going to Brazil. Someone mentioned to me the other day, how stomach sick his wife was in Brazil all the time. I was surprised since I never really heard that before, except for some occasional ones, which I am also famous for... Anyway, I asked him what type of food they were eating and he said that she loved Brazilian fruits, in particular papayas. That she ate several papayas a day.... Anyway, I recommend you read about Papayas (Mamão) before you eat several of them per day:
The papaya, rich in vitamin, B, C, match, carboidratos, calcium, iron and potassium, is laxative, calmante, diurético, assists in the digestion of foods and absorption of nutrients for the organism, attenuates the inflammations, the swells and the burnings, alliviates pains ..... (taken from http://www.frutasnobrasil.com/mamao.html Babel translation).
Let's have a fruit juice in Rio in one of the Juice Houses (casa de suco), you can have a different juice every day. Photo was taken from Copacabana Tropical Sucos Guide - great page in English about the Juice Houses in Rio.
Here is a list of fruits
